In 2016 research into the use of a bacterium called Wolbachia as a method of biocontrol was published showing that invasion of Ae. aegypti by the endosymbiotic bacteria allows mosquitos to be resistant to certain arboviruses such as dengue fever and Zika virus strains currently circulating. In 2017 Alphabet, Inc. started the Debug Project to infect males of this species with Wolbachia bacteria, interrupting the reproductive cycle of these animals.


The species was first named (as Culex aegypti) in 1757 by Fredric Hasselquist in his treatise Iter Palaestinum. Hasselquist was provided with the names and descriptions by his mentor, Carl Linnaeus. This work was later translated into German and published in 1762 as Reise nach Palästina. Since the latter is an uncritical reproduction of the former, they are both considered to antedate the starting point for zoological nomenclature in 1758. Nonetheless, the name Aedes aegypti was frequently used, starting with H. G. Dyar in 1920.
To stabilise the nomenclature, a petition to the International Commission on Zoological Nomenclature was made by P. F. Mattingly, Alan Stone, and Kenneth L. Knight in 1962. It also transpired that, although the name Aedes aegypti was universally used for the yellow fever mosquito, Linnaeus had actually described a species now known as Aedes (Ochlerotatus) caspius. In 1964, the commission ruled in favour of the proposal, validating Linnaeus' name, and transferring it to the species for which it was in general use.
The yellow fever mosquito belongs to the tribe Aedini of the dipteran family Culicidae and to the genus Aedes and subgenus Stegomyia. According to one recent analysis, the subgenus Stegomyia of the genus Aedes should be raised to the level of genus. The proposed name change has been ignored by most scientists; at least one scientific journal, the Journal of Medical Entomology, has officially encouraged authors dealing with aedile mosquitoes to continue to use the traditional names, unless they have particular reasons for not doing so. The generic name comes from the Ancient Greek ἀηδής, aēdēs, meaning "unpleasant" or "odious".


Two subspecies are commonly recognized:
Aedes aegypti subsp. aegypti
Aedes aegypti subsp. formosus
This classification is complicated by the results of Gloria-Soria et al., 2016. Although confirming the existence of these two major subspecies, Gloria-Sora et al. finds greater worldwide diversity than previously recognized and a large number of distinct populations separated by various geographic factors.


Aedes albopictus (Stegomyia albopicta), from the mosquito (Culicidae) family, also known as the (Asian) tiger mosquito or forest mosquito, is a mosquito native to the tropical and subtropical areas of Southeast Asia. In the past few centuries, however, this species has spread to many countries through the transport of goods and international travel. It is characterized by the white bands on its legs and body.
This mosquito has become a significant pest in many communities because it closely associates with humans (rather than living in wetlands), and typically flies and feeds in the daytime in addition to at dusk and dawn. The insect is called a tiger mosquito for its striped appearance, which resembles that of the tiger. Ae. albopictus is an epidemiologically important vector for the transmission of many viral pathogens, including the yellow fever virus, dengue fever, and Chikungunya fever, as well as several filarial nematodes such as Dirofilaria immitis. Aedes albopictus is capable of hosting the Zika virus and is considered a potential vector for Zika transmission among humans.


In 1894, a British-Australian entomologist, Frederick A. Askew Skuse, was the first to scientifically describe the Asian tiger mosquito, which he named Culex albopictus (lat. culex "gnat", "midge" and albopictus "white-painted"). Later, the species was assigned to the genus Aedes (gr. άηδής, "unpleasant") and referred to as Aedes albopictus. Like the yellow fever mosquito, it belongs to the subgenus Stegomyia (Gr. στέγος, "covered, roofed", referring to the scales that completely cover the dorsal surface in this subgenus, and μυία, "fly") within the genus Aedes. In 2004, scientists explored higher-level relationships and proposed a new classification within the genus Aedes and Stegomyia was elevated to the genus level, making Aedes albopictus now Stegomyia albopicta. This is, however, a controversial matter, and the use of Stegomyia albopicta versus Aedes albopictus is continually debated.


The adult Asian tiger mosquito is less than 10 mm (0.39 in) long from end to end with a striking white and black pattern. The variation of the body size in adult mosquitoes depends on the density of the larval population and food supply within the breeding water. Since these circumstances are seldom optimal, the average body size of adult mosquitoes is considerably smaller than 10 mm. For example, the average length of the abdomen was calculated to be 2.63 mm (0.104 in), the wings 2.7 mm (0.11 in), and the proboscis 1.88 mm (0.074 in).
The males are roughly 20% smaller than the females, but they are morphologically very similar. However, as in all mosquito species, the antennae of the males in comparison to the females are noticeably bushier and contain auditory receptors to detect the characteristic whine, almost inaudible to humans, of the female. The maxillary palps of the males are also longer than their proboscis, whereas the females' maxillary palps are much shorter. (This is typical for the males of the Culicinae.) In addition, the tarsus of the hind legs of the males is more silvery. Tarsomere IV is roughly 75% silver in the males whereas the females' is only about 60% silver.
The other characteristics do not differentiate between sexes. A single silvery-white line of tight scales begins between the eyes and continues down the dorsal side of the thorax. This characteristic marking is the easiest and surest way to identify the Asian tiger mosquito.
The proboscis is dark colored, the upper surface of the end segment of the palps is covered in silvery scales, and the labium does not feature a light line on its underside. The compound eyes are distinctly separated from one another. The scute, the dorsal portion of an insect's thoracic segment, is black alongside the characteristic white midline. On the side of the thorax, the scutellum, and the abdomen are numerous spots covered in white-silvery scales.
Such white-silvery scales can also be found on the tarsus, particularly on the hind legs that are commonly suspended in the air. The bases of tarsomeres I through IV have a ring of white scales, creating the appearance of white and black rings. On the fore legs and middle legs, only the first three tarsomeres have the ring of white scales, whereas tarsomere V on the hind legs is completely white. The femur of each leg is also black with white scales on the end of the "knee". The femora of the middle legs do not feature a silver line on the base of the upper side, whereas, the femora on the hind legs have short white lines on base of the upper side. The tibiae are black on the base and have no white scales.
The terga on segments II through VI of the abdomen are dark and have an almost triangular silvery-white marking on the base that is not aligned with the silvery bands of scales on the ventral side of the abdomen. The triangular marking and the silvery band are only aligned on abdominal segment VII. The transparent wings have white spots on the base of the costae. With older mosquito specimens, the scales could be partially worn off, making these characteristics not stand out as much.
As with other members of the mosquito family, the female is equipped with an elongated proboscis that she uses to collect blood to feed her eggs. The Asian tiger mosquito has a rapid bite and an agility that allows it to escape most attempts by people to swat it. By contrast, the male member of the species primarily feeds on nectar and does not bite.
The female lays her eggs near water, not directly into it as other mosquitoes do, but typically near a stagnant pool. However, any open container containing water will suffice for larvae development, even with less than an ounce (30mL) of water. It can also breed in running water, so stagnant pools of water are not its only breeding sites. It is more likely to lay eggs in water sources near flowers than in water sources without flowers. It has a short flight range (less than 200 m (220 yd)), so breeding sites are likely to be close to where this mosquito is found.
Other mosquito species may be visually confused with the tiger mosquito. Comparison with approved pictures is the best way to determine the species with certainty. Behavioral cues like almost-silent flight and difficulty in catching combined with knowledge of the range of local endemic mosquitoes may also aid this process.


Some mosquitoes in North America, such as Ochlerotatus canadensis, have a similar leg pattern. In North and South America, Ae. albopictus can be distinguished from Aedes taeniorhynchus since only Ae. albopictus has back markings.
In Europe, the mosquito Culiseta annulata, which is very common, but does not occur in high densities, can be mistaken for an Asian tiger mosquito because of its black-and-white-ringed legs. However, this species is missing the distinctive white line that runs from the middle of its head and down the thorax. It is also considerably larger than Ae. albopictus, is not black and white, but rather beige and grey striped, and has wings with noticeable veins and four dark, indistinct spots. The Tree Hole mosquito or Aedes geniculatus – a native to Europe and North Africa- has also been mistaken for Ae. albopictus. This is because the Tree Hole mosquito has very white scales on a very similar body.
In the eastern Mediterranean area, Ae. albopictus species can be mistaken for Aedes cretinus, which also belongs to the subgenus Stegomyia and uses similar breeding waters. Aedes cretinus also has a white stripe on the scute, but it ends shortly before the abdomen, and also has two additional stripes to the left and right of the middle stripe. So far Aedes cretinus is only located in Cyprus, Greece, Macedonia, Georgia and Turkey.
In Asia, the Asian tiger mosquito can be mistaken for other members of the subgenus Stegomyia, particularly the yellow fever mosquito Aedes aegypti (the most prevalent species in the tropics and subtropics), because both species display a similar black and white pattern. It can be hard to distinguish Ae. albopictus from the closely related Aedes scutellaris (India, Indonesia, Papua New Guinea, and the Philippines), Aedes pseudoalbopictus (India, Indonesia, Malaysia, Myanmar, Nepal, Taiwan, Thailand, and Vietnam) and Aedes seatoi (Thailand).


Like other mosquito species, only the females require a blood meal to develop their eggs. Apart from that, they feed on nectar and other sweet plant juices just as the males do. In regards to host location, carbon dioxide and organic substances produced from the host, humidity, and optical recognition play important roles.
The search for a host takes place in two phases. First, the mosquito exhibits a nonspecific searching behavior until it perceives host stimulants, whereupon it secondly takes a targeted approach. For catching tiger mosquitoes with special traps, carbon dioxide and a combination of chemicals that naturally occur in human skin (fatty acids, ammonia, and lactic acid) are the most attractive.
The Asian tiger mosquito particularly bites in forests during the day, so has been known as the forest day mosquito. Depending upon region and biotype, activity peaks differ, but for the most part, they rest during the morning and night hours. They search for their hosts inside and outside of human dwellings, but are particularly active outside. The size of the blood meal depends upon the size of the mosquito, but it is usually around 2 μl. Their bites are not necessarily painful, but they are more noticeable than those from other kinds of mosquitoes. Tiger mosquitoes generally tend to bite a human host more than once if they are able to.
Ae. albopictus also bites other mammals besides humans, as well as birds. The females are always on the search for a host and are persistent but cautious when it comes to their blood meal and host location. Their blood meal is often broken off before enough blood has been ingested for the development of their eggs, so Asian tiger mosquitoes bite multiple hosts during their development cycle of the egg, making them particularly efficient at transmitting diseases. The mannerism of biting diverse host species enables the Asian tiger mosquito to be a potential bridge vector for certain pathogens that can jump species boundaries, for example the West Nile virus.


Primarily, other mosquito larvae, flatworms, swimming beetles, fungi, ciliates, paramecia, protozoans which act as parasites, predatory copepods, and spiders are natural enemies of the larval stage of Asian tiger mosquitoes.
Toxorhynchites larvae, a mosquito genus that does not suck blood, feeds upon other mosquito larvae and are often found with tiger mosquito larvae. Flatworms and small swimming beetles are considered natural predators.
Fungi from the genus Coelomomyces (order Blastocladiales) develop inside the visceral cavity of mosquito larvae. The species Coelomomyces stegomyiae was first found on the Asian tiger mosquito.
Paramecia, or ciliates, can also affect Ae. albopictus larvae, and the first detected species was Lambornella stegomyiae (Hymenostomatida: Tetrahymenidae). The virulence, mortality rate, and subsequent possibilities of Lambornella being implemented as a biological remedy to control Ae. albopictus, however, has conflicting views.
Sporozoans of the genus Ascogregarina (Lecudinidae) infect the larval stage of mosquitoes. The species Ascogregarina taiwanensis was found in Asian tiger mosquitoes. When the adult mosquitoes emerge from their pupal case, they leave the infectious intermediary stage of parasites in the water and close off the infection cycle. Infected adults are generally smaller than non-infected adults and have an insignificantly higher mortality rate; therefore, food supply and larval density apparently play a role. In competitive situations, an infection with sporozoans can also reduce the biological fitness of other uninfected mosquitoes. However, the use of the parasites as an effective biological remedy to control mosquito populations is implausible because the host must reach the adult stage for the transmission of the parasites.
Though they do not commonly occur in the natural habitats of Asian tiger mosquitoes, predatory copepods from the family Cyclopidae seem to willingly feed on them given the opportunity. Relatives of different genera could therefore present a possibility in the control of tiger mosquitoes.
Predators of adult Ae. albopictus in Malaysia include various spider species. Up to 90% of the gathered spiders from rubber plantations and a cemetery fed upon Asian tiger mosquitoes. Whether the spiders would have an effect on the mosquito population is still unclear. Tiger mosquitoes were abundantly present despite the existence of the spiders.


The Asian tiger mosquito originally came from Southeast Asia. In 1966, parts of Asia and the island worlds of India and the Pacific Ocean were denoted as the area of circulation for the Asian tiger mosquito. Ae. albopictus as a native to tropical and subtropical regions with warm and humid climate, is active all year long; however, it has been adapting successfully to cooler, temperate regions, where they hibernate over winter. Eggs from strains in the temperate zones are more tolerant to the cold than ones from warmer regions. The species can even tolerate snow and temperatures under freezing. Adult tiger mosquitoes can survive throughout winter in suitable microhabitats.


Since the mid-1960s, the tiger mosquito has spread to Europe, the Americas, the Caribbean, Africa, and the Middle East. As of 2008 Ae. albopictus was one of the 100 world's worst invasive species according to the Global Invasive Species Database.
As of 2006, Ae. albopictus was not native to Australia and New Zealand. The species was introduced there multiple times, but has yet to establish itself. This is due to the well-organized entomological surveillance programs in the harbors and airports of these countries. Nevertheless, as of 2006 it has become domestic on the islands in the Torres Strait between Queensland, Australia, and New Guinea.
In Europe, Asian tiger mosquitos first emerged in Albania in 1979, introduced through a shipment of goods from China. In 1990–1991, they were most likely brought to Italy in used tires from Georgia (USA), and since then have spread throughout the entire mainland of Italy, as well as parts of Sicily and Sardinia. Since 1999, they have established themselves on the mainland of France, primarily southern France. In 2002, they were also discovered in a vacation town on the island of Corsica, but did not completely establish themselves there until 2005. In Belgium, they were detected in 2000 and 2013, in 2001 in Montenegro, 2003 in Canton Ticino in southern Switzerland, and Greece, 2004 in Spain and Croatia, 2005 in the Netherlands and Slovenia, and 2006 in Bosnia and Herzegovina. In the fall of 2007, the first tiger mosquito eggs were discovered in Rastatt (Baden-Wuerttemberg, Germany). Shortly before, they were found in the northern Alps of Switzerland in Canton Aargau. since 2010, it has also been sighted increasingly in Malta during summer. In September 2016, Public Health England found eggs, though no mosquitos, in a lorry park at Folkestone service station on the M20, near Westenhanger, which is 6 miles West of the Eurotunnel. The Swiss Autobahns are especially of concern. Governments and universities in Switzerland cooperate every year to monitor the invasion using traps at Autobahn rest stations, and also at airports and commercial hubs.
In the United States, this species invaded the Southern United States in the 1980s and rapidly spread northward into novel climate compared to its native range. It was initially found in 1983 in Memphis, Tennessee. then at the Port of Houston in a 1985 shipment of used tires, and spread across the South up the East Coast to become prevalent in the Northeast. It was not discovered in Southern California until 2001, then eradicated for over a decade; however, by 2011, it was again being found in Los Angeles County traps, then over the next two years expanded its range to Kern County and San Diego County.
As of 2013, North American land favoring the environmental conditions of the Asian tiger mosquito was expected to more than triple in size in the coming 20 years, especially in urban areas. As of 2017 Aedes albopictus mosquitoes have been identified in 1,368 counties in 40 U.S states. A 2019 study in Nature Microbiology that modeled expansion of Aedes albopictus due to climate change, urbanization, and human movement found that the species would likely continue to spread throughout the coming decades.
In Latin America, the Asian tiger mosquito was first discovered 1986 in Brazil and in 1988 in Argentina and Mexico, as well. Other parts of Latin America where the Asian tiger mosquito was discovered are the Dominican Republic in 1993, Bolivia, Cuba, Honduras, and Guatemala in 1995, El Salvador in 1996, Paraguay in 1999, Panama in 2002, and Uruguay and Nicaragua in 2003.
In Africa, the species was first detected in 1990 in South Africa. In Nigeria, it has been domestic since at least 1991. It spread to Cameroon in 1999/2000, to the Bioko Island of Equatorial Guinea in 2001, and to Gabon in 2006.
In the Middle East, the species was detected in Lebanon in 2003 and in Syria in 2005; the first record in Israel was published in 2003.


Ae. albopictus can outcompete and even eradicate other species with similar breeding habitats from the very start of its dispersal to other regions and biotopes. In Kolkata, for example, it was observed in the 1960s that egg depositing containers were being settled by the Asian tiger mosquito in city districts where the malaria mosquito (genus Anopheles) and yellow fever mosquito (Aedes aegypti) had both been eliminated by the application of DDT. This may be because primarily the inner walls of the houses were treated with DDT to kill the mosquitoes resting there and fight the malaria mosquito. The yellow fever mosquito also lingers particularly in the inside of buildings and would have been also affected. The Asian tiger mosquito rests in the vicinity of human dwellings would therefore have an advantage over the other two species. In other cases where the yellow fever mosquito was repressed by the Asian tiger mosquito, for instance in Florida, this explanation does not fit. Other hypotheses include competition in the larval breeding waters, differences in metabolism and reproductive biology, or a major susceptibility to sporozoans (Apicomplexa).
Another species which was suppressed by the migrating Ae. albopictus was Ae. guamensis in Guam.
The Asian tiger mosquito is similar, in terms of its close socialization with humans, to the common house mosquito (Culex pipiens). Among other differences in their biology, Culex pipiens prefers larger breeding waters and is more tolerant to cold. In this respect, no significant competition or suppression between the two species likely occurs.
A possible competition among mosquito species that all lay their eggs in knotholes and other similar places (Ae. cretinus, Ae. geniculatus, and Anopheles plumbeus) has yet to be observed.
In Europe, the Asian tiger mosquito apparently covers an extensive new niche. This means that no native, long-established species conflict with the dispersal of Ae. albopictus.


Ae. albopictus is known to transmit pathogens and viruses, such as the yellow fever virus, dengue fever, Chikungunya fever, and Usutu virus. There is some evidence supporting the role of Ae. albopictus in the transmission of Zika virus, which is primarily transmitted by the related Ae. aegypti.
The Asian tiger mosquito was responsible for the Chikungunya epidemic on the French Island La Réunion in 2005–2006. By September 2006, an estimated 266,000 people were infected with the virus, and 248 fatalities occurred on the island. The Asian tiger mosquito was also the transmitter of the virus in the first and only outbreak of Chikungunya fever on the European continent. This outbreak occurred in the Italian province of Ravenna in the summer of 2007, and infected over 200 people. Evidently, mutated strains of the Chikungunya virus are being directly transmitted through Ae. albopictus particularly well and in such a way that another dispersal of the disease in regions with the Asian tiger mosquito is feared.
On the basis of experimental evidence and probability estimates, the likelihood of mechanical or biological transmission of HIV by insects is virtually nonexistent.


Wolbachia infection are the most common infection in arthropods today, and over 40% of arthropods have contracted it. Wolbachia can be transmitted from parent to offspring or between breeding individuals. Wolbachia is easily transmitted within the Ae. albopictus mosquito due to the effects it has on fecundity in females. Once female Asian tiger mosquitos have contracted the infection, they produce more eggs, give birth more frequently, and live longer than uninfected females. In this way, Wolbachia provides a fitness advantage to the infected females and prevents uninfected females from reproducing. This allows control of the spread of diseases that many species carry by suppressing reproduction of the individuals with the harmful disease, but without the Wolbachia infection. Wolbachia can also be used to transfer certain genes into the population to further control the spread of diseases.


In the natural environment, Wolbachia and the Asian tiger mosquito are in a symbiotic relationship, so both species benefit from each other and can evolve together. The relationship between Wolbachia and its host might not have always been mutualistic, as Drosophila populations once experienced decreased fecundity in infected females, suggesting that Wolbachia evolved over time so that infected individuals would actually reproduce much more. The mechanism by which Wolbachia is inherited through maternal heredity is called cytoplasmic incompatibility. This changes the gamete cells of males and females, making some individuals unable to mate with each other. Although little is known about why cytoplasmic incompatibility exists, Wolbachia infection creates a fitness advantage for infected females, as they can mate with either infected or uninfected males. Despite this, infected males cannot reproduce with uninfected females. Therefore, over time, a population exposed to Wolbachia transitions from a few infected individuals to all individuals becoming infected, as the males that cannot reproduce successfully do not contribute to future generations. This is called population replacement, where the population's overall genotype is replaced by a new genotype. This shows how populations of Asian tiger mosquitoes can vary in number of Wolbachia-infected individuals, based on how often the infection is transmitted. Due to Wolbachia's ability to transmit from one host to the next, it can change the average genotype of a population, potentially reducing the population's gene flow with other nearby populations.


Also, bidirectional cytoplasmic incompatibility occurs when an infected male carrying one strain of Wolbachia reproduces with an infected female carrying a different strain of Wolbachia. This also results in failed reproduction. Bidirectional cytoplasmic incompatibility also has evolutionary implications for populations of Ae. albopictus and other vectors of the infection. This is because bidirectional cytoplasmic incompatibility in Wolbachia creates unviable offspring, reducing gene flow between two populations, which can eventually lead to speciation.


Ae. albopictus is very difficult to suppress or to control due to its remarkable ability to adapt to various environments, its close contact with humans, and its reproductive biology.
The containment of infestations is generally effected by public health services through area-wide integrated control plans, which aim to reduce the nuisance perceived by populations and the risks of viraemic transmission. Such plans consist of different activities that include entomological surveillance, larvicide treatments in public and private areas, information campaigns, and treatments against adult mosquitoes in the zones affected by suspected cases of transmissible viroses.
Efficient monitoring or surveillance is essential to prevent the spread and establishment of this species. In addition to the monitoring of ports, warehouses with imported plants, and stockpiles of tires, rest areas on highways and train stations should be monitored with appropriate methods.


The control of Asian tiger mosquitoes begins with destroying the places where they lay their eggs, which are never far from where people are being bitten, since they are weak fliers, with only about a 180-m (650-ft) lifetime flying radius. Puddles that last more than three days, sagging or plugged roof gutters, old tires holding water, litter, and any other possible containers or pools of standing water should be drained or removed. Bird baths, inlets to sewers and drainage systems holding stagnant water, flower pots, standing flower vases, knotholes, and other crevices that can collect water should be filled with sand or fine gravel to prevent mosquitoes from laying their eggs in them.
Any standing water in pools, catchment basins, etc., that cannot be drained, or dumped, can be periodically treated with properly labeled insecticides or Bacillus thuringiensis israelensis (Bti), often formed into doughnut-shaped "mosquito dunks". Bti produces toxins which are effective in killing larvae of mosquitoes and certain other dipterans, while having almost no effect on other organisms. Bti preparations are readily available at farm, garden, and pool suppliers.
Flowing water will not be a breeding spot, and water that contains minnows is not usually a problem, because the fish eat the mosquito larvae.


In any case, an efficient surveillance is essential to monitor the presence of tiger mosquitoes and the effect of control programs. Ovitraps are normally used for the monitoring of Ae. albopictus. They are black water containers with floating Styrofoam blocks or small wooden paddles that are in contact with the surface of the water. Female tiger mosquitoes lay their eggs on these surfaces. Through the identification of these eggs or of the larvae that hatch from these eggs in the laboratory, the presence and abundance of mosquito species can be estimated. Versions of these traps with an adhesive film (sticky traps) that catch the egg-depositing mosquitoes make the analysis much easier and quicker, but are more complicated in terms of handling. The results of ovitraps are often variable and depend on the availability of alternative egg-depositing waters. Due to this, it is best to use them in large numbers and in conjunction with other monitoring methods.
To date, few effective traps for adult Asian tiger mosquitoes are available. Those traps that catch other species of mosquitoes do not catch tiger mosquitoes efficiently. A form of an ovitrap called a lethal ovitrap mimics the breeding site for Ae. albopictus just like the monitoring tool, but it has the added benefit of containing chemicals that are toxic to the mosquitoes when they enter, but do not harm humans. These traps have had success in some countries to control Aedes mosquito populations. A new trap type has now been shown to catch significant numbers of Ae. albopictus. This device, with the help of a ventilator, produces an upward air current of ammonia, fatty acids, and lactic acids that takes a similar form and smell of a human body. With the addition of carbon dioxide, the efficacy of the trap is increased. This means a suitable tool is available for trapping adult tiger mosquitoes, and for example, examining the existence of viruses in the trapped mosquitoes. Previously, the mosquitoes had to be collected from volunteers to be studied, which is ethically questionable, especially during epidemics. Recent research also indicates this trap type may also have a use as a control tool; in a study in Cesena, Italy, the number of biting tiger mosquitoes was reduced in places where traps were installed.
An amino acid substitution mutation – F1534C – is overwhelmingly the most common voltage-gated sodium channel in A. albopictus in Singapore. This channel being the target of pyrethroids, this is suspected to be a knockdown resistance (kdr) mutation, and that that is the reason for its prevalence.


Although the Wolbachia infection is prevalent in arthropod species, especially the Asian tiger mosquito, it is a useful mechanism for inhibiting the spread of dengue. Ae. aegypti individuals, a close relative of Ae. albopictus, with an artificial Wolbachia infection, cannot transmit dengue, an infectious virus, but they can pass on the Wolbachia infection to other populations. This could lead to many more discoveries in disease control for Ae. albopictus and other mosquito species. In addition, due to the cytoplasmic incompatibility caused by Wolbachia, the artificial infection of males can serve as a biological control as they are unable to reproduce successfully with uninfected females (unidirectional CI). When artificially infected males are unable to reproduce, the population size can be controlled, thereby reducing the transmission of the harmful disease of interest. Artificial infection of males is achieved by the removal of cytoplasm from infected oocytes, which is then transferred into embryos prior to the blastoderm stage.


The long-tailed tit (Aegithalos caudatus), also named long-tailed bushtit, is a common bird found throughout Europe and the Palearctic. The genus name Aegithalos was a term used by Aristotle for some European tits, including the long-tailed tit.


The long-tailed tit was formally described by the Swedish naturalist Carl Linnaeus in 1758 in the tenth edition of his Systema Naturae under the binomial name Parus caudatus.  The specific epithet caudatus is the Latin word for "tailed". Linnaeus did not invent this Latin name. "Parus caudatus" had been used by earlier authors such as the Swiss naturalist Conrad Gessner in 1555, the Italian naturalist Ulisse Aldrovandi in 1599, and the English ornithologist Francis Willughby in 1676. Willughby listed the English name as the "long tail'd titmouse". Its previous common nickname in everyday English was the bum-towel, from the shape of its tail.
The long-tailed tit was first classified as a true tit of the Parus group. Parus has since been split from the Aegithalidae, with the latter becoming a distinct family containing three genera:
Aegithalos (long-tailed tits), five species including A. caudatus
Psaltria (pygmy bushtit), monotypic
Psaltriparus (American bushtit), monotypic.
This is the only representative of the Aegithalidae in northern Eurasia. The long-tailed tit exhibits complex global variation with 17 races recognised, divisible into three groups:
the A. c. caudatus group in northern Europe and Asia. A. c. caudatus has a pure white head
the A. c. europaeus group in southern and western Europe, north-east China, and Japan. Separating A. c. rosaceus from other members of the A. c. europaeus group though is problematic, relying on varying thickness of the crown stripes and amount of streaks and colour on the underparts
the A. c. alpinus group in Mediterranean Europe and south-west Asia.
The silver-throated bushtit (Aegithalos glaucogularis) from eastern China was formerly considered conspecific but the plumage is distinctive and there are significant genetic differences.
Where the groups meet there are extensive areas occupied by very variable ‘hybrids’. The British long-tailed tit, subspecies A. c. rosaceus, belongs to the A. c. europaeus group.


This species has been described as a tiny (at only 13–15 cm (5–6 in) in length, including its 7–9 cm (3–3+1⁄2 in) tail), round-bodied tit with a short, stubby bill and a very long, narrow tail. The sexes look the same and young birds undergo a complete moult to adult plumage before the first winter. The plumage is mainly black and white, with variable amounts of grey and pink.


Vocalisations are a valuable aid to locating and identifying these birds. When in flocks they issue constant contact calls and are often heard before they are seen. They have three main calls, a single high pitched pit, a ‘triple trill’ eez-eez-eez, and a rattling schnuur. The calls become faster and louder when the birds cross open ground or if an individual becomes separated from the group.


The long-tailed tit is globally widespread throughout temperate northern Europe and the Palearctic, into boreal Scandinavia and south into the Mediterranean zone. It inhabits deciduous and mixed woodland with a well-developed shrub layer, favouring edge habitats. It can also be found in scrub, heathland with scattered trees, bushes and hedges, in farmland and riverine woodland, parks and gardens. The bird's year-round diet of insects and social foraging bias habitat choice in winter towards deciduous woodland, typically of oak, ash and locally sycamore species. For nesting, strong preference is shown towards scrub areas. The nest is often built in thorny bushes less than 3 metres (10 feet) above the ground.


The long-tailed tit is insectivorous throughout the year. It eats predominantly arthropods, preferring the eggs and larvae of moths and butterflies. Occasional vegetable matter is taken in the autumn.


The nest of the long-tailed tit is constructed from four materials: lichen, feathers, spider egg cocoons and moss, with over 6,000 pieces used for a typical nest. The nest is a flexible sac with a small, round entrance on top, suspended either low in a gorse or bramble bush or high up in the forks of tree branches. The structural stability of the nest is provided by a mesh of moss and spider silk. The tiny leaves of the moss act as hooks and the spider silk of egg cocoons provides the loops; thus forming a natural form of velcro. The tit lines the outside with hundreds of flakes of pale lichens - this provides camouflage. Inside, it lines the nest with more than 2,000 downy feathers to insulate the nest. Nests suffer a high rate of predation with only 17% success.


Extensive work has been done at Wytham Wood, Oxfordshire, in Germany and Japan.
Outside the breeding season they form compact flocks of six to seventeen birds, composed of family parties (parents and offspring) from the previous breeding season, together with any extra adults that helped to raise a brood. These flocks will occupy and defend territories against neighbouring flocks. The driving force behind the flocking behaviour is thought to be that of winter roosting, being susceptible to cold; huddling increases survival through cold nights.
From July to February, the non-breeding season, long-tailed tits form flocks of relatives and non-relatives, roosting communally. When the breeding season begins, the flocks break up, and the birds attempt to breed in monogamous pairs. Males remain within the winter territory, while females have a tendency to wander to neighbouring territories.
Pairs whose nests fail have three choices: try again, abandon nesting for the season or help at a neighbouring nest. It has been shown that failed pairs split and help at the nests of male relatives, recognition being established vocally. The helped nests have greater success due to higher provisioning rates and better nest defence. At the end of the breeding season, in June and July, the birds reform the winter flocks in their winter territory.


Due to high predation, there is a high nest failure rate. If nest failure occurs after the beginning of May, failed breeders will not try to re-nest, but may become helpers at a nest of another, usually related, pair. In one study, around 50% of nests had one or more helpers. By helping close relatives, helpers gain indirect fitness benefits by increasing the survivability of related offspring. Helpers may also gain greater access to mates and territories in the future. Helpers also gain experience raising young and therefore their future offspring have greater survivability rates.
Males and females are equally likely to become helpers. Parents may allow the care of helpers to be additive to their own efforts, or on the other extreme, they may reduce their efforts with the care of the helpers. Juvenile males have a higher survivability than juvenile females, although the survival rate for adults of the two sexes is the same. Offspring that were raised with helpers have a higher survivability than offspring raised without. Failed breeders that became helpers have a higher survivability than failed breeders who did not. This may be because of the reduced energy expenditure from sharing a nest. This is similar to acorn woodpeckers and green wood hoopoes. However, failed breeders that did not help are more likely to breed successfully in subsequent years, so there may be a cost of helping. This may be due to helpers having relatively poorer body conditions at the end of the breeding season, similar to pied kingfisher and white-winged chough. Successful breeders have a survivability rate around the survivability of failed breeders who became helpers.


Globally, the species is common throughout its range, only becoming scarce at the edge of the distribution. The IUCN, BirdLife International and The British Trust for Ornithology (BTO) all list the long-tailed tit as a ‘species of least concern’, currently under little or no threat and reasonably abundant.
Due to their small size they are vulnerable to extreme cold weather, with population losses of up to 80% being recorded in times of prolonged cold. It is thought that populations rapidly return to previous levels due to high breeding potential.


Cramp, Stanley; Perrins, C.M., eds. (1993). "Aegithalos caudatus Long-tailed tit". Handbook of the Birds of Europe the Middle East and North Africa. The Birds of the Western Palearctic. Vol. VII: Flycatchers to Strikes. Oxford: Oxford University Press. pp. 133–145. ISBN 978-0-19-857510-8.


The common iora (Aegithina tiphia) is a small passerine bird found across the tropical Indian subcontinent and Southeast Asia, with populations showing plumage variations, some of which are designated as subspecies. A species found in scrub and forest, it is easily detected from its loud whistles and the bright colours. During the breeding season, males display by fluffing up their feathers and spiral in the air appearing like a green, black, yellow, and white ball.


In 1747 the English naturalist George Edwards included an illustration and a description of the common iora in the second volume of his A Natural History of Uncommon Birds. He used the English name "The Green Indian Fly-Catcher". Edwards based his hand-coloured etching on a specimen that had been sent from Bengal to the silk-pattern designer and naturalist Joseph Dandridge in London. When in 1758 the Swedish naturalist Carl Linnaeus updated his Systema Naturae for the tenth edition, he placed the common iora in the genus Motacilla. Linnaeus included a brief description, coined the binomial name Motacilla tiphia and cited Edwards' work. The common iora is now placed in the genus Aegithina that was introduced in 1816 by the French ornithologist Louis Jean Pierre Vieillot. The genus name Aegithina is from Ancient Greek aigithos or aiginthos, a mythical bird mentioned by Aristotle and other classical authors. The etymology of specific epithet tiphia is uncertain. It may be from the Ancient Greek tuphē, tiara, from Tiphys who in Greek mythology was the helmsman of the Argonauts.
Eleven subspecies are recognised:
A. t. multicolor (Gmelin, JF, 1789) – southwest India and Sri Lanka
A. t. deignani Hall, BP, 1957 – south, east India and north, central Myanmar
A. t. humei Baker, ECS, 1922 – central peninsular India
A. t. tiphia (Linnaeus, 1758) – north India to west Myanmar
A. t. septentrionalis Koelz, 1939 – northwest Himalayas
A. t. philipi Oustalet, 1886 – south-central China, east Myanmar, north Thailand and north, central Indochina
A. t. cambodiana Hall, BP, 1957 – southeast Thailand, Cambodia and south Vietnam
A. t. horizoptera Oberholser, 1912 – southeast Myanmar and southwest Thailand, Malay Peninsula, Sumatra and nearby islands
A. t. scapularis (Horsfield, 1821) – Java and Bali
A. t. viridis (Bonaparte, 1850) – central, south Borneo
A. t. aequanimis Bangs, 1922 – north Borneo and west Philippines


Ioras have a pointed and notched beak with a culmen that is straight. The common iora is sexually dimorphic, males in the breeding season have a black cap and back adding to a black wing and tail at all seasons. Females have greenish wings and an olive tail. The undersides of both are yellow and the two white bars on the wings of the male are particularly prominent in their breeding plumage. The males in breeding plumage have a very variable distribution of the black on the upperparts and can be confused with Marshall's iora, however, the latter always has white tips to the tail. The nominate subspecies is found along the Himalayas and males of this population are very similar to females or have only a small amount of black on the crown. In northwestern India, septentrionalis is brighter yellow than others and in the northern plains of India humei males in breeding plumage have a black cap and olive on the upper mantle. In southwestern India and Sri Lanka multicolor has the breeding males with a jet black cap and mantle. The forms in the rest of southern India are intermediate between multicolor and humei with more grey-green on the rump (formerly considered as deignani but now used for the Burmese population).
Several other populations across Southeast Asia are designated as subspecies including philipi of southern China and northern Thailand/Laos, deignani of Myanmar, horizoptera of southern Myanmar and the island chain of Sumatra, cambodiana of Cambodia, aeqanimis of Palawan and northern Borneo, viridis of Borneo and scapularis of Java and Bali.


Ioras forage in trees in small groups, gleaning among the branches for insects. They sometimes join mixed species feeding flocks. The call is a mixture of churrs, chattering and whistles, and the song is a trilled wheeeee-tee. They may sometimes imitate the calls of other birds such as drongos.
During the breeding season, mainly after the monsoons, the male performs an acrobatic courtship display, darting up into the air fluffing up all his feathers, especially those on the pale green rump, then spiralling down to the original perch. Once he lands, he spreads his tail and droops his wings. Two to four greenish white eggs are laid in a small and compact cup-shaped nest made out of grass and bound with cobwebs and placed in the fork of a tree. Both male and female incubate and eggs hatch after about 14 days. Nests predators include snakes, lizards, crow-pheasant and crows. Nests may also be brood-parasitized by the banded bay cuckoo.
Ioras moult twice in a year and the plumage variation makes them somewhat complicated for plumage based separation of the populations.
A species of Haemoproteus, H. aethiginae, was described from a specimen of the common iora from Goa.


The northern saw-whet owl (Aegolius acadicus) is a small owl native to North America. Saw-whet owls are one of the smallest owl species in North America. They can be found in dense thickets, often at eye level, although they can also be found some 20 feet up. Saw-whets are often in danger of being preyed upon by larger owls and raptors. Northern saw-whet owls are also migratory birds without any strict pattern.


The scientific description of one of the subspecies of this owl is attributed to the Rev. John Henry Keen who was a missionary in Canada in 1896. Adults are 17–22 cm (6.7–8.7 in) long with a 42–56.3 cm (16.5–22.2 in) wingspan.  They can weigh from 54 to 151 g (1.9 to 5.3 oz) with an average of around 80 g (2.8 oz), making them one of the smallest owls in North America. They are similar in size to the American robin. Northern saw-whet owls do not exhibit sexual dimorphism through their plumage and were often sexed by size dimorphism, where females are larger than males. Females on average weight 100 g and males on average weight 75 g. Northern saw-whet owls have porphyrin pigments in their flight feathers. When exposed to a UV light the ventral side of the wing, the feathers will fluoresce a neon pink. This is used in order to estimate molt and age in adult northern saw-whet owls.
The northern saw-whet owl has a round, light, white face with brown and cream streaks; they also have a dark beak and yellow eyes. Juveniles have dark a brown head and wings, and a tawny rust colored breast and belly. There is also a distinct white, Y shaped coloration between their eyes.  The juveniles can often be confused with the juvenile Boreal owls. Northern saw-whet owls resemble the short-eared owl, because they also lack ear tufts, but are much smaller. The underparts are pale with dark shaded areas; the upper parts are brown or reddish with white spots. They are quite common, but hard to spot.
There are two subspecies of the northern saw-whet owl: the Aegolius acadicus acadicus found all around North America and the non-migratory Aegolius acadicus brooksi endemic to the Haida Gwaii archipelago in British Columbia.  A.a. brooksi is identified by a darker, buffier plumage and has been proposed as a separate species, the Haida Gwaii saw-whet owl. Isolated populations of northern saw-whet owls in the Allegheny Plateau and Southern Appalachian Mountains have been found to be morphological different than mid-range owls and as genetically distinct as the subspecies A.a.brooksi in British Columbia.


The northern saw-whet owl makes a repeated tooting whistle sound. Some say they sound like a saw being sharpened on a whetstone. They usually make these sounds to find a mate, so they can be heard more often April through June when they are looking for mates. Despite being more common in spring, they do vocalize year round. The advertising too-too-too call has been heard up to 300 meters away through forest. At least 11 different vocalizations have been reported for the northern saw-whet owl. These include the Advertising call,  the Rapid call, Whine, Ksew call, Tssst call, Squeaks, Twittering call (similar to an American Woodcock), Guttural chuck, and begging calls of nestlings. Two additional calls only recorded in brooksi include the Transition Call and Alternate Whine. Non-vocal sounds such as bill snapping are used as a warning call by adults, juveniles and nestlings usually when approached up close or when in the hand.


The northern saw-whet owl's hearing is very sophisticated, due to vertically asymmetrical ears and different shape of the ear openings.  Because the sound reaches the ears at a different time and is of different intensity, the northern saw-whet owl can very precisely localize its prey.  Such accurate sound localization allows it to hunt in a complete darkness by hearing alone. A study by Beatini et al showed that the northern saw-whet owl had a possible frequency sensitivity of 0.7 to 8.6 kHz with the best sensitivity ranging from 1.6 to 7.1 kHz. This allows it to hunt in the dark purely by sound.


Their habitat is coniferous forests, sometimes mixed or deciduous woods, across North America. Most birds nest in coniferous type forests of the North but winter in mixed or deciduous woods. They also love riparian areas because of the abundance of prey there. They live in tree cavities and old nests made by other small raptors. Some are permanent residents, while others may migrate south in winter or move down from higher elevations. Their range covers most of North America south of the boreal forest, including southeastern and southcentral Alaska, southern Canada, most of the United States and the central mountains in Mexico.
Some have begun to move more southeast in Indiana and neighboring states. Buidin et al. did a study of how far north the northern saw-whet owls breed and they found that they can breed northward of 50° N, farther than ever recorded before. Their range is quite extensive and they can even breed in the far north where most birds migrate from to breed. They are an adaptive species that can do well in the cold.
There are two semi-isolated permanent populations in the eastern part of the United States. This first is a population along the West Virginia border in the Allegheny Plateau. The second population is in the higher elevations (>4000 ft) of the southern Appalachian Mountains of western North Carolina, eastern Tennessee, and southwestern Virginia. Although there are abundant populations in the Northern and Western Regions of North America, in some counties of North Carolina, it is currently listed as a threatened species due to a decline in suitable habitat. This is due to loss of boreal forests from hemlock woolly adelgid, logging, and pollution.


Northern saw-whet owls lay about four or six white-colored eggs in natural tree cavities or woodpecker holes. Males will often sing from a nest site and cache food in nest sites in order to attract a female. The father does the hunting while the mother watches and sits on her eggs. Females can have more than one clutch of eggs each breeding season with different males. Once the offspring in the first nest have developed their feathers the mother will leave the father to care for them and go find another male to reproduce with. This type of mating is sequential polyandry. They compete with boreal owls, starlings and squirrels for nest cavities and their nests may be destroyed or eaten by those creatures as well as nest predators such as martens and corvids. Saw-whet owls of all ages may be predated by any larger species of hawks or owls, of which there are at least a dozen that overlap in range including Accipiter hawks, which share with the saw-whet owls a preference for wooded habitats with dense thickets or brush.
In 2014 nesting northern saw-whet owls were found in breeding nest boxes in the Southern Appalachian mountains. This is the most southeastern known breeding area in the United States.


These birds wait on a high perch at night and swoop down on prey. They mainly eat small organisms with a strong focus on small mammals in their diet. Swengel and Swengel (1992) reviewed ten studies that found northern saw-whet owls eating almost exclusively mammals (88% to 100%), with most of the mammals being rodents (85% to 99+%).  Specifically in their Wisconsin study, the Swengels counted saw-whet owls as most often eating deer mice (Peromyscus; ~68% of captured prey), voles (Microtis pennsylvunicus and M. ochrogaster; ~16%), and shrews (~9%; Blarina brevicauda and Sorex cinereus). A similar study by Holt and Leroux (1996) in Montana found saw-whet owls eating more voles (60%) than other mammal species. Engel et al. (2015) also found in the saw-whet owl a strong preference for small mammals (89%), with 55% of prey being two species of voles.
Holt and Leroux compared the eating habits of northern saw-whet owls to northern pygmy owls and found that they prey on different animals for their main food source, with the saw-whet owl's diet 98% small mammals, while for pygmy owls over one-third of their prey was birds. Their study concluded that these owls could adapt depending on the prey and also with the other predators in the areas where they live.  Engel et al. (2015) in Chain O'Lakes State Park, Illinois, during the winter of 1987–88, compared northern saw-whet owls to long-eared owls.  Engel confirmed the saw-whet owl's strong preference for small mammals.  Their diet appeared varied in the winter, and was less tied to one mammal than was the long-eared owl; at times, northern saw-whet owls hunted larger prey, such as the meadow vole (M. pennsylvanicus).
Other mammals preyed on occasionally include shrews, squirrels (largely chipmunks and red squirrels), various other mice species, flying squirrels, moles and bats. Also supplementing the diet are small birds, with passerines such as swallows, sparrows, kinglets and chickadees favored. However, larger birds, up to the size of rock pigeon (which are typically about 4 times as heavy as a saw-whet owl) can even be taken. On the Pacific coast they may also eat crustaceans, frogs and aquatic insects. Like many owls, these birds have excellent hearing and exceptional vision in low light.


Aegopodium podagraria, commonly called ground elder, is a species of flowering plant in the carrot family Apiaceae that grows in shady places. The name "ground elder" comes from the superficial similarity of its leaves and flowers to those of elder (Sambucus), which is not closely related. Other common names include herb gerard, bishop's weed, goutweed, gout wort, snow-in-the-mountain, English masterwort and wild masterwort. It is the type species of the genus Aegopodium. It is native to Europe and Asia, but has been introduced around the world as an ornamental plant, where it occasionally poses an ecological threat as an invasive exotic plant.


This herbaceous perennial grows to a height of 100 cm (39 in) from underground rhizomes. The stems are erect, hollow, and grooved. The upper leaves are ternate, broad and toothed. It flowers in spring and early summer. Numerous flowers are grouped together in an umbrella-shaped flowerhead known as a compound umbel. The main umbel is further divided into several secondary umbels known as umbellets or umbellules. Each umbellet has 15 to 20 rays (pedicels) that are each topped with a single, small, five-petaled white flower. They are visited by many types of pollinating insects.
The fruits, produced in late summer and autumn, are small and have long curved styles.


Aegopodium podagraria is distributed widely in the temperate zone of western Asia and the whole of mainland Europe. It has been introduced elsewhere, including Ireland, the United Kingdom, the United States, Canada, Australia (including Tasmania), New Zealand, and Japan.


Seed dispersal and seedling establishment is typically limited by shading, and new establishments from seed are restricted to disturbed areas. However, Aegopodium podagraria readily spreads over large areas of ground by underground rhizomes. Once established, the plants are highly competitive, also in shaded environments, and can reduce the diversity of ground cover, and prevent the establishment of tree and shrub seedlings. Because of its limited seed dispersal ability, short-lived seed bank and seedling recruitment, the primary vector for dispersal to new areas are human plantings as an ornamental, medicinal or vegetable plant, as well as by accidentally spreading rhizomes by dumping of garden waste. It spreads rapidly under favorable growing conditions. Because of this it has been described as a nuisance species, and been labeled one of the "worst" garden weeds in perennial flower gardens.


A. podagraria has been introduced around the world, including in North America, Australia, New Zealand, and Japan, most commonly as an ornamental plant. It readily establishes and can become naturalized in boreal, moist-temperate, and moist-subtropical climates. It is an "aggressive" invader in the upper Great Lakes region and northeastern North America, Australia, Tasmania, and New Zealand. It can pose an ecological threat due to its invasive nature, with potential to crowd out native species. Because of its potential impacts on native communities and the difficulty of its control, it has been banned or restricted in some jurisdictions outside its native range, including in Connecticut, Massachusetts, Wisconsin, and Vermont in the USA.


Once established, goutweed is difficult to eradicate. The smallest piece of rhizome left in the ground will quickly form a sturdy new plant. All-green goutweed may be more persistent and spread more rapidly than ornamental, variegated goutweed varieties, making the all-green type particularly difficult to control. And all-green, wild type forms are known to reappear from seeds of variegated varieties.
Integrative management strategies that combine herbicide with landscape cloth, bark mulch, and hand weeding to control goutweed in a garden are largely unsuccessful because sprouting occurs from either rhizomes or root fragments left in the soil. Hand pulling, raking, and digging followed by monitoring to control goutweed may be effective; however, caution must be taken to remove the entire rhizome and root system. Removing flowers before seed set may help control the spread of goutweed. Because goutweed's starch reserves are typically depleted by spring, removal of leaves in spring could be effective in starving the plant. Once goutweed has been removed, the patch should be carefully monitored periodically for a few years. New shoots should be dug up and destroyed. Revegetation with other plant materials is recommended.
Systemic herbicides such as glyphosate are recommended because A. podagraria will regrow if merely defoliated.
The most effective means of control is to prevent its establishment in natural communities. It is thus recommended to plant goutweed only on sites not adjacent to wildlands and in gardens where root spread can be restricted (e.g., between a sidewalk and a house). However, the aggressive nature of this plant makes even this strategy risky. Several states have banned sales of goutweed (also known as bishop's weed).


A variegated form is grown as an ornamental plant. However, it is banned in several states due to its invasiveness. Seeds from the variegated form may revert to the more aggressive "green form."


In Eurasia, it is used as a food plant by the larvae of some species of Lepidoptera, including dot moth, grey dagger and grey pug, although A. podagraria is not the exclusive host to any of these species.


The tender leaves have been used in antiquity and throughout the Middle Ages as a spring leaf vegetable, much as spinach was used. It is commonly used for soup. Young leaves are preferred as a pot herb. It is best picked from when it appears (as early as February in the UK) to just before it flowers (May to June). If it is picked after this point, it takes on a pungent taste and has a laxative effect. However, it can be stopped from flowering by pinching out the flowers, ensuring the plant remains edible if used more sparingly as a pot herb.
It also had a history as a medicinal herb to treat gout and arthritis, applied in hot wraps externally upon boiling both leaves and roots together. Ingested, the leaves have a diuretic effect and act as a mild sedative. Its use as a medicinal herb has largely declined during the modern era.
The plant is said to have been introduced into Great Britain by the Romans as a food plant and into Northern Europe as a medicinal herb by monks. It is still found growing in patches surrounding many monastic ruins in Europe, and descriptions of its use are found among monastic writings, such as in Physica by Hildegard von Bingen.


The white-throated swift (Aeronautes saxatalis) is a swift of the family Apodidae native to western North America, south to cordilleran western Honduras. Its coastal range extends as far north as Northern California, while inland it has migratory populations found throughout the Great Basin and Rocky Mountain regions, ranging as far north as southern British Columbia. White-throated swifts are found in open areas near cliffs, rock faces, or man-made structures, where they roost. Swifts are social birds, and groups are often seen roosting and foraging for flying insects together.


The white-throated swift is medium-sized bird that is primarily black and white. Its back and wings are blackish-brown or black, and its breast, belly, chin, and throat are white. In newly molted adults, the dark feathers may have a slight greenish sheen, though this is rarely observable in the field. Sexes cannot be distinguished by plumage. Juvenile (first basic) plumage is similar to adult (definitive basic) plumage, but with the feathers on juveniles' heads and necks appearing duller and paler.
Adults are generally 15–18 centimeters in length, and have a tail with a relatively shallow 10 millimeter-deep notch. Adult swifts weigh between 28 and 36 grams, with a mean weight recorded as 32.5 grams, and there is no difference in size between males and females. The white-throated swift has a wingspan of 35.5 cm. White-throated swifts can appear similar to American black swifts and Vaux's swifts, which also occur in western North America, but they can be distinguished by their white underparts which both other species lack.


The order in which white-throated swifts are placed is debated, with some taxonomies placing them in Caprimulgiformes, but others putting them in Apodiformes. The difficulty in taxonomic placement is largely due to the morphological similarities between swifts which make determining the history of evolutionary divergence difficult. At lower taxonomic levels, White-throated swifts belong to the family Apodidae and the genus Aeronautes.Aeronautes includes only two other species, the Andean swift (Aeronautes andecolus) and the white-tipped swift (Aeronautes montivagus). There are two subspecies: A. s. saxatalis, and A. s. nigrior. The A. s. saxatalis subspecies comprises birds that winter in North America south to the Isthmus of Tehantepec in Oaxaca, Mexico, while birds of the A. s. nigrior subspecies are found wintering below Oaxaca south to Honduras. Birds of A. s. saxatalis tend to have a more prominent superciliary streak, darker upper parts, and a broader white abdominal streak than those of A. s. nigrior.


White-throated swifts are year-round residents of coastal and southern California, southern Arizona, southern New Mexico, western Texas, central Mexico, and the Sierra Madre Occidental and Oriental mountains. Migratory breeding populations can be found from Arizona and New Mexico north to southern British Columbia, and from central California east to eastern Colorado and Wyoming. In the southern part of its migratory range, birds arrive in mid-March and depart in mid-October, while in the northern portion, they do not arrive until mid-April to early-May, and depart in late-August to mid-September. There are two main areas in which non-breeding wintering populations can be found: the first includes southwestern California, eastern Arizona, the Texas Panhandle, while the second is in El Salvador, Guatemala, Honduras, and the Mexican state of Chiapas.


Swifts roost in cliffs, bluffs, and canyons, as well as man-made structures like bridges, overpasses, and walls of quarries. In natural settings, swifts form colonies of as many as 400–500 birds in protected cliff crevices that are generally 6–50 meters above the ground. White-throated swifts will sometimes roost and nest in amongst colonies of swallows, including cliff, violet-green, and northern rough-winged swallows. While foraging, white-throated swifts are found flying over meadows, agricultural fields, and open areas along the edges of ridges and hills.


White-throated swifts are rapid fliers who rarely land except to roost. Swifts usually fly 10–100 meters above the ground, and can be observed taking advantage of wind currents and updrafts to gain speed. White-throated swifts usually leave their roosts in the morning, and will remain flying and foraging all day until late afternoon or evening. While in flight, swifts can sometimes be observed bathing by hitting the surface of the water with their underside, which is followed by airborne preening. Occasionally, they will fight with one another while in flight, and may chase or strike other white-throated swifts or violet-green swallows (Tachycineta thalassina).


Swifts are aerial insectivores who frequently forage in areas of rising air along the edges of canyons, foothills, or mountains to capture insects. White-throated swifts have also been observed foraging over agricultural lands, and are known to follow harvesting machinery to capture insects disturbed by the equipment. Stomach content analysis has found that beetles, flies, bees, and true bugs (Hemiptera) constitute a majority of the white-throated swift's diet. Adult swifts nourish their nestlings by carrying a bolus of arthropods in their buccal cavity, and feeding it to the young. Swifts derive most of their water from their diet, but can also be skimming the surface of ponds to drink.
Known predators of White-throated swifts include peregrine falcons, prairie falcons, and American kestrels. When predators are detected, swifts are known to quickly lower their altitude and fly just above the vegetation. There is no data available on levels of nest predation.


White-throated swifts make vocalizations while in the air that are described as "staccato chattering", and may also make a sharp one- or two-note call or a shrill drawn-out "scree" call. In the morning and evening, "twittering" sounds may be made at their roost sites. Additionally, juveniles may make begging sounds that are higher-pitched versions of the adult's shrill scree call.


During the courtship season, white-throated swifts may perform gliding displays and plummeting courtship falls prior to forming monogamous pairs. Once a pair is established, nests made of plant material and feathers held together with saliva are built on rocky cliff faces or human-made structures. These nests are usually 8–10 centimeters across, and 2.5–2.8 centimeters deep, and may be used for several years in a row. An average of 4–5 white matte eggs are laid over the course of 4–6 days, with incubation generally beginning only after the last egg is laid. In southern parts of their range, egg-laying occurs in April, but in more northerly areas, clutches are usually laid throughout May, with a median first-egg date of May 13. The incubation period lasts on average 24 days, with swifts weighing approximately 2 grams upon hatching. Both parents feed the nestlings, and by the time of fledging, swifts may weigh up to 46 grams. There are no documented cases of swifts attempting a second brood if the first nest fails.


Across North America, white-throated swift populations have declined by 2.8% from 1966–1998, which is considered to be a significant decline. Such declines could be related to loss of roosting and nesting sites from quarrying, mining, and the demolition of older buildings, as well as reduction in food supply due to pesticide use. However, in certain areas swift populations appear to have increasing trends, and most populations appear stable. The patchy distribution of this species makes interpreting these data difficult, but the apparent overall decline is of concern given the concurrent declines of other aerial insectivores.


Aesculus californica, commonly known as the California buckeye or California horse-chestnut, is a species of buckeye native to California and southwestern Oregon.


It is a large deciduous shrub or small tree, up to 4–12 m (13–39 ft) tall, with gray bark often coated with lichens and mosses. It typically is multi-trunked, with a crown as broad as it is high. Trees are long lived, with an estimated lifespan between 250–280 (300 maximum) years. The leaves are dark green, palmately compound with five (rarely seven) leaflets. Each leaflet is 6–17 cm (2.4–6.7 in) long, with a finely toothed margin and (particularly in spring) downy surfaces. The leaves are tender and prone to damage from both spring freezing or snow and summer heat and desiccation.
The flowers are sweet-scented, white to pale pink, borne on erect panicles 15–20 cm (6–8 in) long and 5–8 cm (2–3 in) broad. The fruit is a fig-shaped capsule 5–8 cm (2–3 in) long, containing a large, round, orange-brown seed, measuring 2–7 cm (0.8–2.8 in). The seeds are poisonous and are the largest known of any temperate (non-tropical) plant species.
A. californica has adapted to its native Mediterranean climate by growing during the wet late winter and spring months and entering dormancy in the dry summer months, though those growing in coastal regions tend to hold on to their leaves until mid-autumn.


The only Aesculus variety native to the West, A. californica is widely distributed in California, growing along the central coast and in the lower elevations of the Sierra Nevada and Cascade Range. Its range extends to the foothills of the Siskiyou Mountains in the Rogue Valley in Oregon.  A small disjunct population is found in the Chino Hills near Chino, California.
It is found growing in a wide range of conditions from crowded, moist, semi-shaded canyon bottoms to dry south-facing slopes and hilltops. In the coastal ranges north of Big Sur it is found growing alone on slopes, or intermingled with valley oak (Quercus lobata), Oregon oak (Q. garryana), coast live oak (Q. agrifolia) and California bay laurel (Umbellularia californica). In the foothills of the Sierra Nevada, A. californica can be found standing alone in grassland at the lowest elevations, intermingled in blue oak woodlands at intermediate elevations, and in mixed evergreen forests of black oak (Q. kelloggii), gray pine (Pinus sabiniana), ponderosa pine (P. ponderosa) and interior live oak (Q. wislizeni) as it nears the limit of its range.


Native American tribes, including the Pomo, Yokuts, and Luiseño, used the poisonous nuts and seeds to stupefy schools of fish in small streams to make them easier to catch. The bark, leaves, and fruits contain the neurotoxic glycoside aesculin, which causes hemolysis of red blood cells. Buckeye also makes a good fireboard for a bow drill or hand drill.
Native groups occasionally used the plant as a food supply; after boiling and leaching the toxin out of the seeds or nut meats for several days, they could be ground into a flour or meal similar to that made from acorns. The nectar and pollen of the flowers is toxic to honeybees, so the trees should not be planted near apiaries. When the shoots are small and leaves are new, they are lower in toxins and are grazed by livestock and wildlife. The flowers are a rich nectar source for many species of butterflies, and squirrels and chipmunks consume the seeds.
It is used as an ornamental plant for its striking leaf buds, lime green foliage, fragrant white flowers, red-brown foliage in mid to late summer, and architectural silver branches through fall.
The tree also acts as a soil binder, which prevents erosion in hilly regions.


Callahan F. 2005 Kalmiopsis Journal, Vol. 12, 2005 Plant of the Year, California Buckeye (Aesculus californica (Spach.) Nutt.) Native Plant Society of Oregon ISSN 1055-419X. (.pdf)
Casebeer, M. (2004). Discover California Shrubs. Sonora, California: Hooker Press. ISBN 0-9665463-1-8.
Bakker, E. (1971). An Island Called California. Berkeley, California: University of California Press. ISBN 0-520-04948-9.
Jepson Flora Project: Aesculus californica
USDA Plants Profile for Aesculus californica (California buckeye)
Calflora database — Aesculus californica
Interactive Distribution Map of Aesculus californica
Aesculus californica — U.C. Photo gallery


Aesculus glabra, commonly known as Ohio buckeye, is a species of tree in the soapberry family (Sapindaceae) native to North America.
Its natural range is primarily in the Midwestern and lower Great Plains regions of the United States, extending southeast into the geological Black Belt of Alabama and Mississippi. It is also found locally in the extreme southwest of Ontario, on Walpole Island in Lake St. Clair.
It is found in a variety of natural habitats, including streambanks, upland mesic forests, and along the margins of old fields. It is typically found in calcareous areas.


The leaves are palmately compound with five 8–16 cm (3.1–6.3 in) long and broad. The flowers are produced in panicles in spring, red, yellow to yellow-green, each flower 2–3 cm (0.79–1.18 in) long with the stamens longer than the petals (unlike the related yellow buckeye, where the stamens are shorter than the petals). The fruit is a round capsule 4–5 cm (1.6–2.0 in) diameter, containing one nut-like seed, 2–3 cm (0.79–1.18 in) in diameter, brown with a whitish basal scar.
The inedible seeds contain tannic acid and are poisonous to both cattle and humans. The young foliage, shoots, and bark are also poisonous to some degree. However it is reported that Native Americans did eat buckeye fruit after boiling it to extract tannin.


Aesculus glabra has little use as a timber tree due to its soft, light wood. Although occasionally seen in cultivation, the large copiously produced fruits make it generally undesirable as a street tree.


The Ohio buckeye is the state tree of Ohio, and its name is an original term of endearment for the pioneers on the Ohio frontier. Subsequently, "buckeye" came to be used as the nickname and colloquial name for people from Ohio. Ohio State University adopted "Buckeyes" officially as its nickname in 1950, and also uses the name for its sports teams. It came to be applied to any student or graduate of the university.
Buckeye candy, made to resemble the tree's nut, is made by dipping a ball of peanut butter fudge in milk chocolate, leaving a circle of the peanut butter exposed. These are a popular treat in Ohio, especially during the Christmas and college football seasons.
Buckeyes (the nuts) are a recurring theme in Bill Watterson's comic, Calvin and Hobbes, often as one of Calvin's tools of torment. Watterson himself grew up in Chagrin Falls, Ohio.


Aesculus hippocastanum is a large tree, growing to about 39 metres (128 ft) tall with a domed crown of stout branches; on old trees the outer branches are often pendulous with curled-up tips. The leaves are opposite and palmately compound, with 5–7 leaflets; each leaflet is 13–30 cm (5–12 in) long, making the whole leaf up to 60 cm (24 in) across, with a 7–20 cm (3–8 in) petiole. The leaf scars left on twigs after the leaves have fallen have a distinctive horseshoe shape, complete with seven "nails". The flowers are usually white with a yellow to pink blotch at the base of the petals; they are produced in spring in erect panicles 10–30 cm (4–12 in) tall with about 20–50 flowers on each panicle. Its pollens are not poisonous for honey bees. Usually only 1–5 fruits develop on each panicle; the shell is a green, spiky capsule containing one (rarely two or three) nut-like seeds called conkers or horse-chestnuts. Each conker is 2–4 cm (3⁄4–1+1⁄2 in) in diameter, glossy nut-brown with a whitish scar at the base.


The common name horse chestnut originates from the similarity of the leaves and fruits to sweet chestnuts, Castanea sativa (a tree in a different family, the Fagaceae), together with the alleged observation that the fruit or seeds could help panting or coughing horses.
Although it is sometimes known as buckeye, for the resemblance of the seed to a deer's eye, the term buckeye is more commonly used for New World members of the genus Aesculus.


Aesculus hippocastanum is native to a small area in the Pindus Mountains mixed forests and Balkan mixed forests of South East Europe. However, it can be found in many parts of Europe as far north as Gästrikland in Sweden, as well as in many parks and cities in the northern United States and Canada.


It is widely cultivated in streets and parks throughout the temperate world, and has been particularly successful in places like Ireland, Great Britain and New Zealand, where they are commonly found in parks, streets and avenues. Cultivation for its spectacular spring flowers is successful in a wide range of temperate climatic conditions provided summers are not too hot, with trees being grown as far north as Edmonton, Alberta, Canada, the Faroe Islands, Reykjavík, Iceland and Harstad, Norway.
In Britain and Ireland, the seeds are used for the popular children's game conkers. During the First World War, there was a campaign to ask for everyone (including children) to collect the seeds and donate them to the government. The conkers were used as a source of starch for fermentation using the Clostridium acetobutylicum method devised by Chaim Weizmann to produce acetone for use as a solvent for the production of cordite, which was then used in military armaments. Weizmann's process could use any source of starch, but the government chose to ask for conkers to avoid causing starvation by depleting food sources. But conkers were found to be a poor source, and the factory only produced acetone for three months; however, they were collected again in the Second World War for the same reason.  In the US state of Ohio, the seeds of the related Aesculus glabra are called 'buckeyes' and give rise to one of the state's symbols and nicknames, the Buckeye State.
The seeds, especially those that are young and fresh, are slightly poisonous, containing alkaloid saponins and glucosides. Although not dangerous to touch, they cause sickness when eaten; consumed by horses, they can cause tremors and lack of coordination.
The horse-chestnut is a favourite subject for bonsai.
Though the seeds are said to repel spiders there is little evidence to support these claims. The presence of saponin may repel insects but it is not clear whether this is effective on spiders.
Aesculus hippocastanum is affected by the leaf-mining moth Cameraria ohridella, whose larvae feed on horse chestnut leaves. The moth was described from North Macedonia where the species was discovered in 1984 but took 18 years to reach Britain.
In Germany, they are commonly planted in beer gardens, particularly in Bavaria. Prior to the advent of mechanical refrigeration, brewers would dig cellars for lagering. To further protect the cellars from the summer heat, they would plant chestnut trees, which have spreading, dense canopies but shallow roots which would not intrude on the caverns. The practice of serving beer at these sites evolved into the modern beer garden.


The seed extract standardized to around 20 percent aescin (escin) is used for its venotonic effect, vascular protection, anti-inflammatory and free radical scavenging properties. Primary indication is chronic venous insufficiency. A Cochrane Review suggested that horse chestnut seed extract may be an efficacious and safe short-term treatment for chronic venous insufficiency, but definitive randomized controlled trials had not been conducted to confirm the efficacy.


Two preparations are considered: whole horse chestnut extract (whole HCE) and purified β-aescin. Historically, whole HCE has been used both for oral and IV routes (as of 2001). The rate of adverse effects is low; in a large German study, 0.6%, consisting mainly of gastrointestinal symptoms. Dizziness, headache and itching have been reported. One serious safety issue is rare cases of acute anaphylactic reactions, presumably in a context of whole HCE.
Another is the risk of acute kidney injury, "when patients, who had undergone cardiac surgery were given high doses of horse chestnut extract i.v. for postoperative oedema. The phenomenon was dose dependent as no alteration in kidney function was recorded with 340 μg/kg, mild kidney function impairment developed with 360 μg/kg and acute kidney injury with 510 μg/kg". This almost certainly took place in a context of whole HCE.
Three clinical trials were since performed to assess the effects of aescin on kidney function. A total of 83 subjects were studied; 18 healthy volunteers given 10 or 20 mg iv. for 6 days, 40 in-patients with normal kidney function given 10 mg iv. two times per day (except two children given 0.2 mg/kg), 12 patients with cerebral oedema and normal kidney function given a massive iv. dose on the day of surgery (49.2 ± 19.3 mg) and 15.4 ± 9.4 mg daily for the following 10 days and 13 patients with impaired kidney function due to glomerulonephritis or pyelonephritis, who were given 20–25 mg iv. daily for 6 days. "In all studies renal function was monitored daily resorting to the usual tests of renal function: blood urea nitrogen (BUN), serum creatinine, creatinine clearance, urinalysis. In a selected number of cases paraaminohippurate and labelled EDTA clearance were also measured. No signs of development of renal impairment in the patients with normal renal function or of worsening of renal function in the patients with renal impairment were recorded." It is concluded that aescin has excellent tolerability in a clinical setting.
Raw horse chestnut seed, leaf, bark and flower are toxic due to the presence of Aesculin and should not be ingested. Horse chestnut seed is classified by the FDA as an unsafe herb. The glycoside and saponin constituents are considered toxic.


A fine specimen of the horse-chestnut was the Anne Frank tree in the centre of Amsterdam, which she mentioned in her diary and which survived until August 2010, when a heavy wind blew it over. Eleven young specimens, sprouted from seeds from this tree, were transported to the United States. After a long quarantine in Indianapolis, each tree was shipped off to a new home at a notable museum or institution in the United States, such as the 9/11 Memorial Park, Central H.S. in Little Rock, and two Holocaust Centers. One of them was planted outdoors in March 2013 in front of the Children's Museum of Indianapolis, where they were originally quarantined.


Bleeding canker. Half of all horse-chestnuts in Great Britain are now showing symptoms to some degree of this potentially lethal bacterial infection.
Guignardia leaf blotch, caused by the fungus Guignardia aesculi
Wood rotting fungi, e.g. such as Armillaria and Ganoderma
Horse chestnut scale, caused by the insect Pulvinaria regalis
Horse-chestnut leaf miner, Cameraria ohridella, a leaf mining moth. Also affecting large numbers of UK trees.
Phytophthora bleeding canker, a fungal infection.


Aesculus pavia, known as red buckeye or firecracker plant (formerly Pavia Rubra), is a species of deciduous flowering plant. The small tree or shrub is native to the southern and eastern parts of the United States, found from Illinois to Virginia in the north and from Texas to Florida in the south. It is hardy far to the north of its native range, with successful cultivation poleward to Arboretum Mustila in Finland.
It has a number of local names, such as scarlet buckeye, woolly buckeye and firecracker plant.
The red buckeye is a large shrub or small tree. It reaches a height of 5–8 m (16–26 ft), often growing in a multi-stemmed form.  Its leaves are opposite, and are composed usually of five elliptical serrated leaflets, each 10–15 cm (4–6 in) long. It bears 10–18-centimetre-long (4–7 in) clusters of attractive dark red tubular flowers in the spring. The flowers are hermaphrodite. The smooth light brown fruits, about 2.5 cm (1 in) or so in diameter, reach maturity in early fall.
There are two varieties:
Aesculus pavia var. pavia: typical red buckeye.
Aesculus pavia var. flavescens: yellow-flowered red buckeye.
The yellow-flowered variety, var. flavescens, is found in higher country in Texas, and hybrids with intermediate flower color occur.
The flowers are attractive to hummingbirds as well as bees. The fruits are rich in saponins, which are poisonous to humans, although not particularly dangerous because they are not ingested easily. The seeds are poisonous. The oils can be extracted to make soap, although this is not viable commercially.
Ornamental cultivars such as the low-growing 'Humilis' have been selected for garden use.
Red buckeye has hybridized with common horse-chestnut (Aesculus hippocastanum) in cultivation, the hybrid being named Aesculus × carnea, red horse-chestnut. The hybrid is a medium-sized tree to 13.5–17 m (45–55 ft) tall, intermediate between the parent species in most respects, but inheriting the red flower color from A. pavia. It is a popular tree in large gardens and parks, most commonly the selected cultivar 'Briotii'.  Hybrids of red buckeye with yellow buckeye (A. flava) have also been found, and named Aesculus × hybrida.


Aeshna constricta, the lance-tipped darner, is a species of darner in the dragonfly family Aeshnidae. It is found in North America.
The IUCN conservation status of Aeshna constricta is "LC", least concern, with no immediate threat to the species' survival. The population is stable. The IUCN status was reviewed in 2017.


The brown hawker (Aeshna grandis) is a large dragonfly about 73 millimetres (2.9 in)  long. It is a distinctive species and is easily recognised, even in flight, by its brown body and bronze wings. At rest, blue spots on the second and third segments of the male's abdomen can be noticed; these are absent in female.
The flight time is mainly July to September. The nymph has stripes on the side of the thorax and distinct banding on the legs.


Aeshna grandis is common in central and eastern Europe. In Europe, it can be found everywhere from Ireland to the Urals, with some exceptions like Scotland, northernmost Scandinavia and the Iberian and Apennine peninsulas. There is a population in the Balkans.
It is widespread in England but commonest in the south-east; local in Ireland and rare in Scotland. It is found on well-vegetated ponds, lakes and canals. It patrols a regular hunting territory around margins which is vigorously defended against intruders.


Aeshna tuberculifera, the black-tipped darner, is a species of darner in the dragonfly family Aeshnidae. It is found in North America.
The IUCN conservation status of Aeshna tuberculifera is "LC", least concern, with no immediate threat to the species' survival. The population is stable. The IUCN status was reviewed in 2017.


The shadow darner (Aeshna umbrosa) is a species of dragonfly in the family Aeshnidae. It is found in almost all of Canada and most states in the United States.


The shadow darner is a large dragonfly with a length of 68 to 78 mm (2.7 to 3.1 in). The base is brownish black in color. Greenish crescent-shaped spots are found at the top of the thorax. The sides of the thorax are marked with two yellowish to yellowish-green diagonal stripes. Its abdomen is marked with bluish green spots. The male shadow darner has paddle-shaped anal appendages.
The naiad of the shadow darner is large in size, with a length of 38 to 43 mm (1.5 to 1.7 in). This naiad is long and slender, which is the typical shape of immature darners. It is mottled green and brown. The shadow darner has a vertically flattened cerci with a spike at the end, which is much brighter than the lance-tipped darner.


The shadow darner patrols along small marshy streams. It is often found feeding along woodland edges or even in deep shadow in full forest. Shadow darners can also be found near ditches, slow streams, and ponds. This darner has a long flight season of late April to November.
The shadow darner naiad feeds on a wide variety of aquatic insects, such as mosquito larvae, other aquatic fly larvae, mayfly larvae, and freshwater shrimp. They also feed on small fish and tadpoles. This adult will eat almost any soft-bodied flying insect, including mosquitoes, flies, butterflies, moths, mayflies, and stoneflies.


The naiad is an active predator and are able to swim by jet propulsion. They squirt water out from the ends of their abdomens. They will generally take several years to mature, and when the immature changes into a dragonfly, it does so at night. This behavior probably was evolved to avoid being eaten be daytime predators. The adult generally flies from late April to November, and does all of its hunting while on the wing. The shadow darner is able to regulate its body temperature which enables it to fly in temperatures too cold for most dragonflies. This dragonfly species in particular seems to be extremely cold tolerant. This dragonfly flies at dusk and in shaded areas, and it flies later into the fall than any species other than the yellow-legged meadowhawk (Sympetrum vicinum).


Male shadow darners establish and defend territories along the shores of slow streams and ponds. After mating, females fly singly, without the male attached, to lay their eggs in the stems and leaves of aquatic plants.


The crimson sunbird (Aethopyga siparaja) is a species of bird in the sunbird family which feed largely on nectar. They may also take insects, especially when feeding their young. Flight is fast and direct on their short wings. Most species can take nectar by hovering like a hummingbird, but usually perch to feed. It has also been unofficially announced as Singapore’s national bird by the Nature Society Singapore.


Crimson sunbirds are tiny, only 11 cm long. They have medium-length thin down-curved bills and brush-tipped tubular tongues, both adaptations to their nectar feeding. The adult male has a crimson breast and maroon back. The rump is yellow and the belly is olive.  The female has an olive-green back, yellowish breast and white tips to the outer tail feathers. In most of the range, males have a long green-blue tail, but A.s. nicobarica of the Nicobar Islands and the former subspecies A. vigorsii (Western crimson sunbird) of the Western Ghats of India lack the long central tail feathers. Their call is chee-cheewee.


The crimson sunbird is a resident breeder in tropical southern Asia from India, through Nepal, Bangladesh and Myanmar to Indonesia and Brunei Darussalam. Two or three eggs are laid in a suspended nest in a tree. This species occurs in forest and cultivated areas.


Agalinis heterophylla is a species of flowering plant in the family Orobanchaceae known as prairie false foxglove. It is found in northern Mexico (Tamaulipas) and the southeastern and central United States.


Agalinis purpurea (known by common names including purple false foxglove and purple gerardia) is an annual forb native to the eastern United States and Canada, which produces purple flowers in late summer or early fall.


Agalinis purpurea is 10 to 120 centimeters tall. The stem is slender, with spreading branches. It has simple opposite leaves, which are 10 to 40 millimeters long, and only 0.5 to 2 millimeters wide. The flowers are racemose on the branches. They are borne on 1 to 8 millimeter long pedicles. Each flower is bilaterally symmetrical, with five 20 to 38 millimeter long petals fused into a corolla tube, and four stamens. The fruit is a round 4 to 6 millimeter long dry capsule that splits open when ripe.


Agalinis purpurea is widely distributed in the eastern United States, although local distribution may be spotty. It has been recorded in Alabama, Arkansas, Connecticut, Washington, D.C., Delaware, Florida, Georgia, Iowa, Illinois, Indiana, Kansas, Kentucky, Louisiana, Massachusetts, Maryland, Michigan, Minnesota, Missouri, Mississippi, North Carolina, Nebraska, New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Virginia, Wisconsin, and West Virginia. It has also been recorded in the Canadian province of Ontario. In Virginia, it grows in habitats such as marshes, swamps, interdune swales, and old fields. The presence of this species is dependent on appropriate habitat, and it may be eliminated from an area by development, changes in land use, or competition with invasive species.


Like other members of the genus Agalinis, this species is hemiparasitic on a variety of hosts, particularly graminoids. Agalinis purpurea uses haustoria to connect its roots with those of its host plants, but it also has green tissues, and performs photosynthesis.


This species is a member of the genus Agalinis, which was formerly placed in the family Scrophulariaceae, but has more recently been placed in the family Orobanchaceae, in keeping with the findings of the Angiosperm Phylogeny Group.


Agalinis tenuifolia, known by the common names common gerardia, slender false foxglove or common false foxglove, is an annual forb native to the eastern and southwestern United States, and Canada, which produces purple flowers in late summer or early fall.


Agalinis tenuifolia is 20 to 60 centimeters tall, with a slender, paniculately branched stem. Its simple opposite leaves are 20 to 50 millimeters long, and only 1 to 3.5 millimeters wide. The flowers are borne on 10 to 20 millimeter long pedicels. Each flower is bilaterally symmetrical, with five 10 to 15 millimeter long petals fused into a corolla tube, and four stamens. The fruit is a round 3 to 7 millimeter long dry capsule that splits open when ripe.


Agalinis tenuifolia is widely distributed in the eastern United States and Canada, although local distribution may be spotty. It has been recorded in the states of Alabama, Arkansas, Colorado, Connecticut, Washington, D.C., Delaware, Florida, Georgia, Iowa, Illinois, Indiana, Kansas, Kentucky, Louisiana, Massachusetts, Maryland, Maine, Michigan, Minnesota, Missouri, Mississippi, North Carolina, North Dakota, Nebraska, New Hampshire, New Jersey, New Mexico, New York, Ohio, Oklahoma, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Virginia, Vermont, Wisconsin, West Virginia, and Wyoming, as well as the Canadian provinces of Manitoba, New Brunswick, Ontario, and Quebec. Agalinis tenuifolia is listed as a species of special concern in the state of Rhode Island. In Virginia it grows in habitats including dry woods and barrens, but particularly in open disturbed areas such as old fields, however, in Michigan, it grows in moist or even marshy ground, including river banks. The presence of this species is dependent on appropriate habitat, and it may be eliminated from an area by development, changes in land use, or competition with invasive species.


Like other members of the genus Agalinis, this species is hemiparasitic on a variety of hosts, particularly graminoids. Agalinis tenuifolia uses haustoria to connect its roots with those of its host plants, but it also has green tissues, and performs photosynthesis.


The beetle is named for its golden-black colour, with a golden bloom on its elytron and thorax. It reaches a length of 10–22 millimetres (0.39–0.87 in).


Their flight time is from May to August. For the larval development the species is quite polyphagous with a wide variety of hosts, probably including Aconitum, Angelica, Anthriscus, Artemisia, Aster, Carduus, Cirsium, Chaerophyllum, Eupatorium, Foeniculum, Gentiana, Helleborus, Heracleum, Peucedanum, Salvia, Senecio, Urtica and Veratrum album. The larvae develop in the stalks of the host plant, working their way down while growing, cutting off the stalk and creating pupal cells near ground level. Adults emerge through a newly cut exit hole in the side of the stalk.


Agapanthus praecox (common agapanthus, blue lily, African lily,  or lily of the Nile) is a popular garden plant around the world, especially in Mediterranean climates. It is native to the Kwa-Zulu Natal and Western Cape provinces of South Africa. Local names include agapant, bloulelie, isicakathi and ubani. Most of the cultivated plants of the genus Agapanthus are hybrids or cultivars of this species. It is divided into three subspecies: subsp.praecox, subsp. orientalis and subsp. minimus.


Agapanthus praecox is a variable species with open-faced flowers. It is a perennial plant that can survive up to 75 years. Its evergreen leaves are 2 cm wide and 50 cm long. Its inflorescence is in umbel. The flowers of the agapanthus are blue, purple or white and bloom from late spring to summer. They give capsules filled with fine black seeds (to be kept cool in sand until sowing). Its stem reaches one meter high. Its roots are very powerful and can break concrete.


This subspecies occurs in the Eastern Cape province of South Africa. It usually grows to between 0.8 and 1 metre tall and has 10-11 leathery leaves. The blue flowers, appear from December to February. These have perianth segments which are greater than 50 mm in length.
Agapanthus praecox subsp. orientalis
This subspecies occurs in the Eastern Cape and southern KwaZulu-Natal. Although it is  about the same height as subsp. praecox, it has up to 20 poisonous, strap-like leaves per plant which are arching and are not leathery. These range in length from 20 to 70 cm long and 3 to 5 cm wide. Flower colour ranges from blue to white. Shiny black seeds are produced in three-sided capsules. These have perianth segments which are less than 50 mm in length.
Agapanthus praecox subsp. minimus
Occurring in the southeastern Western Cape and Eastern Cape, this subspecies is the smallest, ranging in height from 300 to 600 mm. It has a longer flowering season, from November to March. Flower colour includes white and various shades of blue.