There are many food plants for B. impatiens including: “Aster”, Cirsium, Eupatorium, Gelsemium, Malus, Pontederia, Rubus, Solidago, Trifolium, Crocus, Pieris, Rhododendron, barberry, mountain laurel, rose, clover, purple vetch, pickerel weed, purple loosestrife, buttonbush, Beggar’s ticks, goldenrod, boneset, burdock, and Impatiens from which the bee's name may come. The bees can eat the raw materials like pollen and nectar of the flowers but most bees in the colony eat honey that is made using the raw materials since it has higher nutritional value. To create honey, the bees consume the pollen and the nectar, and then regurgitate them, mixing them with enzymes in their stomachs.


Bombus impatiens are hosts to other bees. Ps. Laborious and Bombus citrinus are some examples of parasites. Also, Entromopox-like viruses and prokaryotes called Spiroplasmataceae have been found in the workers. However, there is no known harmful effect to B. impatiens.


Bees play in a significant role in pollinating crops. A decline in bee population leads to a decline in crop yield, which will then result in a reduction in the food supply and cause economic hardships for farmers. Commercially produced B. impatiens is one of the most important species of pollinator bees that are used by greenhouse industry in North America, including Canada and Mexico. They are efficient pollinators and natives to East North America. The interest in B. impatiens has been increased even more due to the decline of pollinator bee population like A. mellifera and the ban on importing B. terrestris into North America. They are used as pollinator bees for tomatoes, blueberries, raspberries, and pumpkins.


Bombus melanopygus, the black-tailed bumble bee, black tail bumble bee or orange-rumped bumblebee, is a species of bumblebee native to western North America.
This bee is widely distributed across western North America, from the Pacific to the Rocky Mountains, and from Alaska to Baja California.
There are two forms of the black-tailed bumblebee:
Red form (“red butts,” Bombus melanopygus melanopygus) found primarily in higher latitudes of  Oregon and points north, and in the Mountain West
Dark color form (Bombus melanopygus edwardsii) is most common in California and southern Oregon
(The second and third abdominal segments are red in northern populations and black in southern; individuals with black segments were previously known as Bombus edwardsii, a separate species. Genetic analyses support the conclusion that the two forms are the same species, with B. edwardsii as a synonym.)
This bumblebee can utilize a number of habitat types, including agricultural and urban areas. It is "one of the few bumblebees still found regularly in San Francisco". It feeds on many types of plants, including manzanitas, Ceanothus, goldenbushes, wild buckwheats, lupines, penstemons, rhododendrons, willows, sages, and clovers. It nests underground or aboveground in structures.
This species is a host to the zombie fly (Apocephalus borealis).


Bombus nevadensis, the Nevada bumblebee, is a species of bumblebee. It is native to North America, where it occurs from Alaska to California in the west, and east to Wisconsin, and in Arizona, New Mexico, and Mexico.


A bumblebee with a long proboscis (tongue) and a short, dense fur, the females (queens and workers) have an entirely black head, while the face and top of the head of the male are yellow. The thorax is yellow, sometimes with a hairless, black spot in the middle. The three first terga (abdominal segments) are yellow, while the rest of the abdomen is black. However, the tip of the tail is more or less red in the male. The average body length is 20 mm (0.79 in) for the queen, 17 mm (0.67 in) (worker) and 14 mm (0.55 in) (male).
The black and gold bumblebee (Bombus auricomus) is sometimes considered a subspecies of this species, B. nevadensis auricomus. Genetic and morphological evidence supports them as separate species.


This species inhabits open areas such as prairies and meadows. It usually nests underground. Food plants include milkvetches, thistles, melilots, bergamot, penstemons, phacelias, salvias, betony, and clovers.


Bombus pensylvanicus, the American bumblebee, is a threatened species of bumblebee native to North America. It occurs in eastern Canada, throughout much of the Eastern United States, and much of Mexico.
Once the most prevalent bumblebee in the southern United States, populations of Bombus pensylvanicus have decreased significantly in recent years, including in its scientific namesake state of Pennsylvania where its numbers are considered critically low. Overall, the population has dropped nearly 90% in just the last 20 years.
Bombus pensylvanicus tends to live and nest in open farmland and fields. It feeds on several food plants, favoring sunflowers and clovers, and functions as a pollinator.


Bombus pensylvanicus belongs to the order Hymenoptera (consisting of ants, wasps, bees, and sawflies), the family Apidae (consisting of Cuckoo, Digger, Carpenter, Bumble, and Honeybees), the Subfamily Apinae (consisting of Honey, Orchid, Bumble, Long-horned, and Digger Bees), and the genus Bombus (consisting of bumblebees). Within Bombus, B. pensylvanicus belongs to the subgenus Thoracobombus, which includes species such as Bombus armeniacus, Bombus pauloensis, Bombus dahlbomii, Bombus fervidus, Bombus humilis, Bombus morio, Bombus muscorum, Bombus pascuorum, Bombus pomorum, Bombus ruderarius, Bombus sylvarum, and Bombus transversalis. Bombus pensylvanicus is sometimes mistaken for B. terricola or B. auricomus, but its closest relative is Bombus sonorus, found in Mexico and Arizona. Scientists sometimes treat Bombus sonorus as a subspecies of Bombus pensylvanicus, although each species maintain differences in male genitalia. Intermediate individuals of B. pensylvanicus and B. sonorus have been found in areas of geographic overlap, but further evidence is needed to distinguish whether B. sonorus is a subspecies of B. pensylvanicus.


Bombus pensylvanicus is a widespread species, characterized as long-tongued. In comparison to its similar species B. sonorus, B. pensylvanicus has a darker color pattern and is located in the eastern United States. Characteristics of B. pensylvanicus include: a yellow thoracic dorsum, a black posterior, 3 initial alternating black and white tergal segments, a long and lanky malar space, and short hair. These characteristics resemble those of B. fervidus and B. auricomus, leading to confusion among species. B. pensylvanicus is similar in color and range to Bombus fervidus. In terms of characteristics within the hive, a larger queen measures 22–26 mm compared to worker at 13–19 mm. Males have an outward penis valve head with a broad banana shape, and often have extensive yellow on the thoracic dorsum posteriorly.
While bees normally forage close to their nests, it has been observed that individuals can return from up to 1.5 miles away. Though there is likely individual variation in homing ability and the time it takes a bee to find its way back to the nest. The method utilized by the bees is most likely trial and error method, not a sixth sense or homing instinct because the bees maintained varying variation in time taken to return to the nest. Males become more common in late summer.


S.A. Cameron observed that bees of the genus Bombus tend to have a comparable morphology throughout their range, thus signifying that behavioral adaptations may play a large part in colonizing different habitats. Mimetic evolution is postulated to account for both interspecific and intraspecific variation in color pattern. Eastern North American B. pensylvanicus and western North American B. sonorus are taxa that have a similar morphology, but have distinct color patterns and different male genitalia. In areas where the two taxa overlap, there is genetic introgression between B. sonorus and B. pensylvanicus, suggesting that the two taxa may actually be conspecific (as they produce fertile offspring), and best considered as subspecies.


Bombus pensylvanicus ranges from the Eastern Great Plains to eastern and central US and southern Canada, and Mexico. The species has become rarer, declining in number mainly in northern parts of its range. B. pensylvanicus generally nests in fields of long grass, but may sometimes nest underground. The species utilizes bundles of hay or long grass to create sheltered nests above ground. Some nest in established crevices and burrows, such as old bird nests, rodent burrows, or in cinder blocks. This species has even been noted to nest in human made objects, like buckets or barns.


Bombus pensylvanicus maintains a reproductive cycle that it similar to other species of bumblebee. Environmental factors as well as accessibility of resources affects the cyclic advancement of the colony. The cycle begins in February and ends around November or December. Female bees can yield eggs without the need for mating, a process known as haplodiploidy. Unfertilized eggs develop into males, whereas fertilized eggs develop into female workers or queen bees. The reproductive cycle begins in July/August, when a male mates with a freshly hatched queen. The fertilized queen stays in hibernation until spring of the next year, waiting for the optimal conditions to search for a nest. In March, the queen bee gathers pollen and nectar, as a source of nutrition and to build a wax pot, and establishes her colony. These colonies most likely arrange and initiate in February. Female workers develop through the pollen collected as it stimulates the ovaries to create eggs, which are fertilized from the males of year before. The queen continues to warm the eggs initially, then the eggs continue their life cycle of development: first larval stage, then pupae, and lastly adult female workers. The female workers care for the nest and eggs, whereas the queen lays eggs. This process of egg to adult bee takes about 4–5 weeks. Initial workers forage and increase the colony size by bringing resources for growth. Thus, workers that hatch later in the year, around midsummer, tend to be larger than initial worker bees. The hives continue to grow, and in late summer there can be more than 200 worker bees. At the point when the size of the hive is sufficient, the queen stops production of a chemical that prevents ovarian production of certain females leading to specify the production of queen bee eggs and male eggs. Certain female workers may produce their own eggs, but the queen will usually get rid of them. The constant battle between the queen and workers continue until late summer when the workers sting the queen to death. The cycle begins again in the winter as the queen bee eggs hatch and the worker bees die.


B. pensylvanicus has a varying stability within its colony cycle. Queens are considered the dominant caste because they are usually the largest bees of the colony. As worker male bees grow larger in average wing length, they become the dominant caste as the number of queens decrease. Wing length of males vary depending upon the point of colony development. Initial males that found the colony tend to have a smaller wing length than the first or second generation of the colony. Food supply is scarce, at first, as the queen is the forager. Until July, the workers are the foraging caste and an enormous increase in body size is observed. The worker proportions decrease when reproductive males develop, representing a turning point in the colony, as male size increase until active bees develop to the size of a queen near November and December when the worker population dissipates. Queens maintain the least amount of standard deviation for average wing length and thus are the most stable caste in the colony. It is postulated that this is because queens are made in a short time span when colony resources have reached its threshold. The activity of B. pensylvanicus in a subtropical zone resemble that of species in temperate zones, maintaining periods where there are no active bees.


Although Bombus pensylvanicus maintains aposematic coloration and defensive stinger, it faces many predators. Predation is likely to be caused by attack to gain the resources of the hive, which contains carbohydrate and protein abundant nectar, larvae, and pollen. Predators consist of mostly mammals such as skunks, bears, and raccoons. Furthermore, bumble bees are predated on by birds for food. Foragers are frequently predated by invertebrates. Crab spiders and cryptically colored ambush bugs ambush bees at flowers to catch them. Robber flies resemble bumble bees and clasp the bumble bees, insert them with enzymes, then eat their internal organs. Mallophora bomboides is a robber fly species that preys specifically on B. pensylvanicus and uses it as a model for Batesian mimicry. Wasps, such as the beewolf species Philanthus bicinctus, intercept bees then paralyze them with venom, using them to nourish the wasp’s larvae. Assassin bugs and dragonflies are also common predators of the bee.


Bumble bees are generally host to a diversity of parasitoids in which the larvae grow inside the living host. The majority of parasitoids for bumble bees are flies and about 30 percent or more bees within the area can be infected. The process of parasitism consists of the fly attaching to the bee in flight and inserting her oviposits between the terga of the bee. The larval fly hatches within the bee host and develops by feeding on the host’s tissues. The bee lives for about two weeks before dying. The fly then pupates and spends the winter inside the bee, fully developed, before it emerges the following year. Bombus pensylvanicus is host to one "cuckoo" bumble bee species, B. variabilis. Hibernating queen bumble bees are parasitized by a nematode worm, Sphaerularia bombi. This parasite does not reduce life span, but instead causes the sterilization of the queen. It has been observed that affected queens forage two to three weeks later than those that are unaffected. Parasitic microorganisms also use bees as their host. Parasitic microorganisms’ effects may be lethal or sublethal. Pathogens may be transmitted within a colony or the bee may be infected at flowers. Tracheal mites (Locustacarus buchneri) leads to reduced foraging efficiency by living in the bee’s alveoli. Certain protozoans and fungi consume the host tissue or gut substances of the bumble bee’s digestive tract, decreasing foraging efficiency, life span, and thus the colony fitness. Bees may contain symbiotic bacteria that offer some immunity to pathogens. Further exposure to habitat loss as well as pesticide exposure may lead to bee predisposition, thus promoting the species’ decay.


Since bumble bees are characterized by a striking color pattern as well as a defensive sting, they are involved in mimetic complexes (both Müllerian mimicry and Batesian mimicry) with other insects that also gain reduced predation. Bombus pensylvanicus is mimicked by various sawflies, day-flying moths (e.g. Hemaris diffinis), beetles, flies, and other bees, such as carpenter and digger bees.


Wesselingh and Arnold (2000) studied pollinator preferences on Iris fulva (red-flowered) and Iris brevicaulis (blue-flowered). B. pensylvanicus preferred purple-flowered hybrids. The bees continued to visit the nearest flowers the majority of the time, demonstrating that movements were usually between a diversity of flower types rather than prioritizing only one type of flower. Thus, a lack of intermediate genotypes of iris hybrids is not due to pollinator preference by B. pensylvanicus, but rather, pollinating behavior is done through mixed mating of alternating flower types of different pollination syndromes.


Johnson tested for intraspecific size resource utilization differences in B. pensylvanicus. In Minnesota, flowers with short corollas and long corollas existed in single and mixed species stands. Foragers with short corollas and shorter proboscises (tongue) were discovered in mixed species stands. Johnson concluded that B. pensylvanicus foragers would preference the corolla length that corresponds with their proboscis length. Further comparison of conspecific foragers of mixed versus single species stands revealed a shorter proboscis length for mixed species in comparison to single species stand for the short corolla. This study postulated that a diversity of flowering species may influence the specific bee that pollinates the species for single species stand.


Bumblebee species have been found to deteriorate substantially in 1940-1960, and continue to decrease presently. Ranges of Bombus pensylvanicus have specifically decreased in Illinois, coinciding with agricultural investment within the state. Lozier and Cameron evaluated genetic structure using microsatellite markers in Illinois to compare genetic variation of historical versus contemporary collections within B. pensylvanicus. It was found that B. pensylvanicus had greater population structure, indicating reduced gene flow and dispersal among populations. It was found that genetic diversity has overall not been significantly altered over time, but there were some reductions in B. pensylvanicus. Slight losses of genetic diversity in B. pensylvanicus may be an indication of the species’ decline. These results were expected because of the recent decrease in population, which would cause declines in genetic diversity for severe bottleneck situations. Thus, the alteration in gene flow may suggest potential future genetic differentiation of the B. pensylvanicus.


Current research states that Bombus pensylvanicus is uncommon and declining quickly. As stated in previous sections, the northern range of B. pensylvanicus has significantly decreased. Once the most abundant species throughout the southern United States, B. pensylvanicus is now a rare species that has been extirpated in certain areas and has suffered declines in others. Conservation efforts are encouraged in order to maintain the species including agriculture with wildlife-friendly techniques including hedgerows and pest management.


Bombus rufocinctus is a species of bumblebee known commonly as the "red-belted bumblebee." It is native to North America where it has a wide distribution across Canada and the western, midwestern, and northeastern United States. It may occur in Mexico.
The queen is 1.6 to 1.8 centimeters long and just under a centimeter wide at the abdomen. It is black with scattered gray and yellowish hairs on the head. The abdomen has many bright yellow hairs and areas of reddish hairs. The worker is 1.1 to 1.2 centimeters long and half a centimeter wide at the abdomen. It is similar to the queen but it may have longer hairs. The male is 1.2 to 1.3 centimeters long and half a centimeter wide at the abdomen. It is mostly black with more yellow on the head and abdomen. This species displays four genetically controlled color polymorphisms: the second and third abdominal terga may have red or black hairs, and the fourth and fifth may be either yellow or black.
This small, short-tongued bee lives in and around wooded areas and it can be found in urban parks and gardens. It feeds on several kinds of plants, including chicories, snakeroots, strawberries, gumweeds, sunflowers, goldenrods, clovers, vetches, and goldeneyes. It usually nests on or above ground level.


Bombus ternarius, commonly known as the orange-belted bumblebee or tricolored bumblebee, is a yellow, orange and black bumblebee. It is a ground-nesting social insect whose colony cycle lasts only one season, common throughout the northeastern United States and much of Canada. The orange-belted bumblebee forages on Rubus, goldenrods, Vaccinium, and milkweeds found throughout the colony's range. Like many other members of the genus, Bombus ternarius exhibits complex social structure with a reproductive queen caste and a multitude of sister workers with labor such as foraging, nursing, and nest maintenance divided among the subordinates.


B. ternarius is a small, fairly slender bumblebee. The queen is 17–19 mm (0.67–0.75 in) long and the breadth of the abdomen is 8.5–9 mm (0.33–0.35 in). The workers are 8–13 mm (0.31–0.51 in), and the drones are 9.5–13 mm (0.37–0.51 in) in length. Both the worker and the drone have abdomens about 4.5–5.5 mm (0.18–0.22 in) in breadth.
The queen and workers have black heads, with a few pale yellow hairs. The anterior and posterior thorax and the first and fourth abdominal segments are yellow, abdominal segments 2 to 3 are orange, and the terminal segments are black. The queen and the workers are close in resemblance, and the most striking difference between them is in the size of their fat deposits. Workers have very little fat, particularly in their abdomen, leaving plenty of room for the honey stomach, an enlargement of the oesophagus in which nectar can be stored on foraging trips. In contrast, in young queens, the abdomen is largely full of fat. This leads to queens being heavier for their size than workers.
The drone has a yellow head with a few black hairs. The coloration of the thorax and abdomen is similar to that of the females, with the exception that the last abdominal segments are yellow on the sides. The fur of the drone is longer than that of the females.
B. huntii, another species of bumblebee common throughout the western United States, is nearly identical in coloration to B. ternarius, though it has primarily yellow facial hairs rather than black.


B. ternarius mainly ranges in the northern parts of the US and much of Canada. Their range extends from the Yukon to Nova Scotia and British Columbia. Their United States territory extends from New York and Pennsylvania to Michigan, Washington, Wyoming, Utah and Montana. The bumblebees are most successful in the northern, temperate climate, but they can rarely be found farther south.
B. ternarius, like most members of its genus, are seasonal, meaning the queen comes out of hibernation in late April to start a new colony. The bumblebee workers fly from May to October when the entire colony dies (except hibernating queens) to start the cycle again.


In late April, the queen comes out of hibernation from under a few inches of loose soil or leaf litter, and begins to search for a nesting site. Bombus ternarius prefer to nest underground in small and shallow cavities like rodent burrows or natural crevices. She flies low to the ground, stopping often to investigate holes in the earth, and once a satisfactory nest site is found, she forages for pollen and nectar to support her future offspring.  Next, the queen secretes a protective waxy coating and builds a grove where she lays fertilized eggs destined to be the first of the new workers. The queen straddles the eggs, allowing for close contact between the ventral surface of her abdomen and thorax and the eggs. This close contact allows the queen to incubate her brood with the heat she generates by pulsing contractions in her abdomen.
These eggs progress through four lifecycle stages starting as an egg, then larva, pupa, and after about a month after laying the egg, the adult workers emerge. Considering that the entire lifecycle of a colony is only about a season long, incubation is necessary because it hastens the development of the first workers. However, the generation of such vast amounts of heat is incredibly costly for the queen. The queen uses an estimated 600 mg of sugar per day to incubate her brood. To obtain this amount of energy, she may need to visit as many as 6,000 flowers. Naturally, during her absence, the brood cools rapidly, so the availability of plentiful and rewarding flowers near the nest site is vital.
The newly hatched workers take over the duty of foraging and expanding the nest. The workers also assist in incubation of the eggs and larvae. B. ternarius nests rarely exceed more than 200 individuals.
In late summer, the queen switches to laying unfertilized eggs, which develop into male drones that are meant for reproduction. Towards the end of her life, the queen reverts to laying fertilized eggs. These eggs give rise to new female queens. The new adult queens forage for food. They use the nest for shelter, but the new queens do not contribute to the nests food reserves. During this time, the new queens mate with roaming male drones, build up reserves of body fat, and fill their nectar crop with honey to survive winter hibernation. The rest of the colony, including the old queen, dies in mid-autumn.


Drones have one function in life: reproduction. They fly in a circuit and deposit a pheromone on prominent places such as tree trunks, rocks, posts, etc., to attract the newly hatched queens. A new queen follows the pheromone trail and mates with the male.
Mating among B. ternarius typically occurs on the ground or in vegetation. The male mounts the female by grabbing her thorax, the queen then extends her stinger and the male inserts his genital capsule. Mating time varies widely from about 10 to 80 minutes, with the sperm being transferred within the first two minutes of copulation. While mating, both the male and female are vulnerable to predators. After the transfer of sperm is complete, the male secretes a sticky substance that hardens into a plug that blocks new sperm for about three days. This prevents other males from impregnating the same queen and competing to fertilize eggs. The plug helps reduce competition and increases the first male's evolutionary success.
Individual colonies have slightly different reproductive strategies. About half of the queens adopt an early switching strategy that produces mostly male drones, and the other half adopt a late switching strategy, giving rise to mostly new queens. Because of this, bumblebee female to male sex ratio differs from the standard Hymenoptera three to one ratio as proposed by the haplodiploidy hypothesis, and sits closer to an even sex ratio. One hypothesis proposes that the reason why bumblebee's sex ratio differ from the characteristic hymenopteran ratio is because of the queen's decision-making. She can decide to adopt an early switching, male-producing strategy, or a late switching, queen-producing strategy. The worker bees have no choice but to go along with the queen's choice. Normally, the workers would work to shift the ratio towards female prevalence, but in the case of B. ternarius, this would disfavor the workers' evolutionary success.


All fertilized eggs are capable of developing into members of either caste, whether the larva will turn into a worker or a queen, regardless of when they are laid during colony development. Some evidence suggests bumblebees can determine the caste of a larva by feeding it a special diet. Larvae are fed a mixture of pollen and nectar combined with proteins secreted by adult bees. These proteins are mainly invertase and amylase produced in the hypopharyngeal gland. This mixture is regurgitated and presented to the larvae in droplets. Future queens may receive additional glandular secretions, but in terms of total protein, pollen, and carbohydrates in the food mixture, larvae of all castes receive the same proportions.  Nurse bees have been observed to feed queen, worker, and male larvae using the contents of the same crop, so it seems unlikely a significant difference exists in the food consumed by larvae of different castes.
By experimentally starving larvae, Pereboom et al. were able to demonstrate larvae produce a cue that stimulates workers to feed them. This suggests the rate at which larvae are fed might at least be partially controlled by the larvae. If feeding had a role in caste determination, this would mean the larvae have a partial say in determining their future caste. Larvae, then, may have to make an economic decision as to whether becoming a worker or a queen is more beneficial.
A more promising explanation of caste determination involves a pheromone excreted by the current queen. The queen excrete a pheromone to which larvae are sensitive between two and five days after emerging from the egg. The presence of the pheromone forces a larva to enter an irreversible pathway towards development as a worker. The absence of this pheromone causes the larva to become a queen. The pheromone has not yet been identified, but the evidence for its existence is convincing. Evidence suggests the pheromone is not airborne, but is transmitted directly by contact from bee to bee and from adults to larvae. Larvae separated from the queen by a fine mesh developed into queens, but if workers were regularly moved from the queen's side to the side the larvae were on, then the larvae developed as workers.


Major plants visited include Rubus, goldenrods, Vaccinium, and milkweeds. B. ternarius eats and collects both nectar and pollen. The nectar is stored in a special internal pouch called the crop, while pollen collects on the hairs on the bumblebee body. The bumblebee pushes the grains of pollen towards its hind legs, where the pollen is pushed into the pollen basket. At the nest, the contents of the nectar crop is regurgitated, where it is mixed with enzymes and allowed to air dry. As the nectar and enzyme mixture dries, honey is created. Pollen is mixed with the nectar and honey to create a protein-rich larval food.
Before the introduction of western honey bees, bumblebees were the only honey-producing bees in North America; however, only small quantities are produced.


B. ternarius, as well as other members of the genus Bombus, live in eusocial colonies in which the individuals in the group act as a single multiorganismal superorganism. Eusociality may have evolved in the bumblebee ancestor as a result of offspring remaining in the nest as adults to help rear their mother's young. The evolution of eusociality can be explained by Hamilton's inclusive fitness theory. The mostly sterile workers forage for food and take care of the colony's needs, while the queen is in charge of reproducing and creating new generations of workers. Toward the end of the colony lifecycle, workers jostle the queen, eat her eggs, and attempt to lay eggs of their own. The workers are not completely sterile, despite their inability to mate, since they have ovaries. Worker eggs always develop into males. The queen usually retaliates by acting aggressively toward the workers and trying to eat the workers’ eggs. However, the queen's retaliation proves insufficient in some cases and the aggressive reproductive bumblebee workers kill her.


The queen's primary role is to reproduce and ensure the colony has a steady supply of new workers. The worker bumblebees are responsible for most of the other chores, such as foraging, nest maintenance, and tending to the larvae. Younger workers typically start life as a worker where most of their time is devoted to working in the nest. Wax in bumblebees is secreted from the underside of the abdomen of the worker. An individual bumblebee's ability to produce wax starts at about the second day of adult life, but starts to decline after the first week. Since wax is only required within the nest, young workers are predisposed towards within-nest work such as nest maintenance. As bumblebees mature, they are more likely to switch over from within-nest duty to foraging. Furthermore, newer foragers generally collect nectar and tend to switch over to collecting pollen as they age. Long ago, foragers of a range of different bumblebee species were noticed to tend to be larger, on average, than bees that performed within-nest work. This trend can best be explained by the observation that larger-sized workers tend to switch from within-nest work to foraging earlier than smaller workers. The very smallest workers never switch to foraging and remain within-nest workers their entire lives.


Bombus ternarius was first named by Thomas Say in 1837. Bombus is Latin for buzzing, and refers to the sound the insects make. The specific name ternarius refers to the number three, which refers to the bumblebees' three colors.


Bombus terrestris, the buff-tailed bumblebee or large earth bumblebee, is one of the most numerous bumblebee species in Europe. It is one of the main species used in greenhouse pollination, and so can be found in many countries and areas where it is not native, such as Tasmania. Moreover, it is a eusocial insect with an overlap of generations, a division of labor, and cooperative brood care. The queen is monandrous which means she mates with only one male. B. terrestris workers learn flower colors and forage efficiently.


B. terrestris is part of the order Hymenoptera, which is composed of ants, bees, and wasps. The family Apidae specifically consists of bees. It is also part of the subfamily Apinae. There are 14 tribe lineages within Apinae, and B. terrestris is in the bumblebee tribe, Bombini. It is in the genus Bombus, which consists entirely of bumblebees, and the subgenus Bombus sensu stricto. This subgenus contains closely related species such as Bombus affinis, Bombus cryptarum, Bombus franklini, Bombus ignitus, Bombus lucorum, Bombus magnus, Bombus occidentalis, and Bombus terricola. There are nine recognized subspecies: B. terrestris africanus, B. terrestris audax, B. terrestris calabricus, B. terrestris canariensis, B. terrestris dalmatinus, B. terrestris lusitanicus, B. terrestris sassaricus, B. terrestris terrestris and B. terrestris xanthopus, each with a distinctive coloration scheme.


B. terrestris are pollen-storing bees that generally feed and forage on nectar and pollen. The queen is between 20 and 22 mm long, males range from 14 to 16 mm, and workers from 11 to 17 mm. Workers have white-ended abdomens, and look just like workers of the white-tailed bumblebee, B. lucorum, a close relative, apart from the yellowish bands of B. terrestris being darker in direct comparison. The queens of B. terrestris have the namesake buff-white abdomen tip ("tail"); this area is white as in the workers in B. lucorum. B. terrestris is unique compared to other bees in that their caste of workers exhibit a wide variation in worker size, with thorax sizes ranging from 2.3 to 6.9 mm in length and masses ranging from 68 to 754 mg.


B. terrestris is most commonly found throughout Europe and generally occupies temperate climates. Because it can survive in a wide variety of habitats, there are populations in the Near East, the Mediterranean Islands, and Northern Africa as well. Additionally, it has escaped captivity after being introduced as a greenhouse pollinator in countries where it is not native, so this bee is now considered an invasive species in many of these places, including Japan, Chile, Argentina, and Tasmania. Nests are usually found underground, such as in abandoned rodent dens. Colonies form comb-like nest structures with egg cells each containing several eggs. The queen will lay egg cells on top of one another. Colonies produce between 300 and 400 bees on average, with a large variation in the number of workers.


Like in most social bees, there are three main social caste divisions in B. terrestris. This ensures a division of labor and efficient colony functioning. Queens become the main female individual to reproduce in a future colony. There is only one per colony. Her sole responsibility is to lay eggs after she founds a nest. This fate is determined for larvae that receive more food, have longer instar stages, and higher levels of juvenile hormone biosynthesis. Workers, an entirely female caste, mainly forage for food, defend the colony, and tend to the growing larvae. They are usually sterile for most of the colony cycle and do not raise their own young. Unlike queens and workers, which develop from fertilized diploid eggs, drones, or male bees, are born from unfertilized, haploid eggs. Drones leave the colony shortly after reaching adulthood to find a mate outside the nest. Mating is their sole role in the colony.


A solitary queen hatched from her abandoned colony initiates the colony cycle when she mates with a male and finds a nest. She will stay in this nest over winter and then will lay a small batch of diploid (female) eggs in the spring. Once these hatch, she tends the larvae, feeding them with nectar and pollen. When the larvae are grown, they pupate, and about two weeks later, the first workers emerge. This is known as the initiation phase of the colony. Workers forage for nectar and pollen for the colony and tend later generations of larvae. The workers are smaller than the queen, and usually die while foraging in the jaws of predators like birds or robberflies. The foraging range and frequency of workers depends on the quality and distribution of available food, but most workers forage within a few hundred meters of their nest.
This first phase can last a variable amount of time in B. terrestris, after which a switch point is reached, and the queen begins to lay some unfertilized eggs, which develop into males. When the male drones emerge from the nest, they do not return, foraging only for themselves. They seek out emerging queens and mate with them. The remaining diploid eggs hatch into larvae that receive extra food and pupate to become new queens. The queen can use pheromones to discourage the workers' inclination to invest more in these larvae, thereby ensuring that not too many become queens. The resolution of this worker/queen conflict can be complex and is discussed below. The colony persists until fall in temperate zones and then workers begin to lay unfertilized eggs that if they mature will become males. At this point, outright aggression among workers and between the queen and workers begins. This is a predictable time point that occurs about 30 days into the colony cycle in very temperate climates.
Usually, the worker-queen conflict will force the queen out and the new workers will become queenless. A "false queen" might take control of the colony for a short period. The newly emerged queens sometimes act as workers and help to raise another brood of queens. During this time they daily leave the nest looking for food, during which time they may mate. Eventually they find a site to dig a “hibernaculum” where they will hibernate until the next spring, when they emerge, seek food — primarily to build up their ovaries — and soon seek a site to found a new nest. (In warmer climates they may skip the hibernation stage.) Almost always the old colony will have died out, and if the site is free of parasites one of the new queens will return and reuse that site.


B. terrestris is a singly mating species. Mating with multiple males might provide benefits of genetic variability among the brood, but it does not happen in this or any but the most highly derived social bees. The lack of multiple matings by B. terrestris queens may be partly due to male interference. B. terrestris males plug the female's sexual tract with a sticky secretion during mating, which appears to reduce the female's ability to successfully mate with other males for several days. However honeybee males also plug the female's reproductive tract to no avail; honeybees mate tens of times on one mating flight. While there may be genetic fitness benefits in colony heterogeneity from a polyandrous mating system, bumblebees are also likely to be monandrous due to social constraints, risks associated with multiple matings, and phylogenetic inertia since the ancestral bees are singly mated. Finding multiple mates might be energetically costly and expose the queen to higher predation risks. Additionally, while queens may prefer multiple matings to ensure more genetic variability and viable offspring, workers are more closely related to full sisters than to paternal half sisters. This is due to haplodiploidy in Hymenopteran social insects in which males (drones) are haploid and females (workers and queens) are diploid. This confers greater genetic similarity between sister workers (relatedness of 0.75) than between mother and offspring (relatedness of 0.5), making the relatedness component of kin selection higher between sisters.


In addition to the queen, the workers can lay eggs. Since workers do not mate, all of their eggs are haploid and will develop into drones. There are multiple factors that determine whether a worker bee will become reproductively active. Workers born early in the first brood are more likely to become egg layers due to their increased size and age, which allows more time for ovarian development. Workers usually have to be at least 30 days old to become an egg layer. Individuals that spend less time foraging and more time near the queen are also more likely to become reproductive. Lastly, due to intense competition for the opportunity to reproduce, older workers often harass the queen by attacking her and buzzing loudly. Once this point is reached the colony is usually abandoned.


Due to the variability in the switch point to male production from worker production of B. terrestris colonies, there are varying levels of sex ratios among nests. Early-switching colonies have a much smaller number of future queens compared to males (1:17.4), which may give them a competitive advantage in mating with later emerging queens. Late-switching colonies have fewer males and a more even sex ratio of 1:1:3, thus indicating the queen's control over her colony (she prefers a 1:1 ratio, since she is equally related to both sons and daughters). On the other hand, workers prefer a 3:1 ratio, as they are more related to each other than to their mother. Although early and late switching colonies are usually balanced equally in numbers in the population, the overall demographic in one study was found to be male biased, resulting in an overall sex ratio of 1:4 (female to males). However, most studies show that this balance of bimodal sex determination between early and late-switching colonies creates the queen's preferred 1:1 sex ratio in B. terrestris populations. This is unusual for monogamous social insects, which usually have a 3:1 sex ratio indicative of worker colony control. B. terrestris often does not conform to standard predictions of sex ratios based on evolutionary theory and haplodiploid theory.


Queen bees can control oogenesis in worker bees by suppressing juvenile hormone (JH) in the workers, which regulates egg development. Among queenless B. terrestris workers, the corpora allata, which secrete JH, was noticeably enlarged compared to queenright workers. JH concentrations were also higher in the hemolymph of queenless workers. This suggests that the presence of a queen is enough to prevent workers from laying eggs, which helps her maintain genetic control over her colony's brood. The mechanism through which the queen induces this behavior is likely through pheromones.


While the queen controls much of the egg laying and larval development in the colony, it is likely that workers play a much bigger role in controlling egg laying than previously thought. Dominant workers will often inhibit younger workers from laying eggs. Workers have low levels of JH and ovarian development during the early stages of the colony cycle and also after the competition point. Workers introduced into queenright and queenless colonies experience similar levels of inhibition from fellow workers during the competition point, indicating the key role of worker policing of fellow nest mates later in the colony cycle. This suggests that worker reproductive development will be highest between early development and the competition point in the colony.


Conflict is expected between the queen and workers over the sex ratio and reproduction of males in the colony, especially in monandrous colonies where workers are more related to their own sons and nephews than to their brothers. In early-switching colonies, workers might start laying eggs when they know it will be in their own genetic interests, perhaps from a cue that indicates the switch point has been reached and the queen is now laying haploid eggs. In late-switching colonies (where the competition point still occurs at the same time in the cycle), workers may start laying eggs when they detect a change in the queen's pheromone that indicate larvae are developing into new queens. Thus, the outcome of this conflict is mediated through the dominance of the queen and the information available to the workers. While it is assumed that queens usually win this conflict, it is still unclear because some studies have indicated that up to 80% of males are produced by workers. These asymmetries in the timing of egg lying and dominance in B. terrestris might explain why it often does not conform to predicted sex ratios and kin-selection hypotheses, although worker bees are more closely related to their nephews (0.375) than to their brothers (0.25) and kinship selection would lead workers to favor their sons over nephews, and nephews over brothers.


Although B. terrestris workers are most directly in competition with the queen for egg laying opportunities, they will still inhibit their sisters from laying eggs in order to have their own sons. This is beneficial to them because they will share more genes with their own sons (.5) rather than their nephews (.375). However, kin theory states that in monandrous colonies, workers will be most closely related to their sisters (0.75) but are more closely related to their sons (0.50) than to their nephews (0.375) and least of all to their brothers (0.25), and would accordingly devote their resources.


Newly emerged workers start out at the bottom of the dominance hierarchy in the social colony. As they age, they move closer to the position of queen. Queen-side workers are often egg layers and interact more frequently with the queen. This social position may pay off later, after the competition point is reached. When the queen is overthrown by the aggression of the workers, the most dominant worker will have the best likelihood of contributing more eggs to the colony brood and will perhaps climb to the position of “false queen.” The queen appears to maintain a constant distance of social dominance from her workers at all points in the cycle, suggesting that she is displaced by the sheer number of workers later in the cycle.


B. terrestris generally forage on a large variety of flower species. Their highest activity is in the morning, with their peak time being noted at around 7-8 am. This is likely because it gets progressively warmer in the afternoon, and foragers prefer ambient temperatures of around 25 °C during nectar and pollen collection.


B. terrestris bees exhibit alloethism, which is where different sized bees perform different tasks. This kind of behavior can be seen most often in foraging activities. Larger bees are more often found foraging outside the nest and will return to the nest with larger amounts of nectar and pollen. It is possible that larger bees might be able to withstand greater temperature variation, avoid predation, and travel larger distances making them selectively advantageous. Distinct social roles based on morphology might also be beneficial for individuals of the colonies, by making the colony operate more efficiently. Small bees can be reared more cheaply and kept for in-nest tasks, while only some larvae will be fed enough to become large foraging bees.


Individuals who return from the nest after a foraging run often recruit other bees in the colony to leave the nest and search for food. In B. terrestris, successful foragers will return to the nest and run around frantically and without a measurable pattern, unlike the ritualized dance of the honeybee. Although the mechanism by which this recruitment strategy functions is unclear, it is hypothesized that running around likely spreads a pheromone that encourages other bees to exit and forage by indicating the location and odor of food nearby. Colonies with lower food stores will often be more responsive to this foraging pheromone. Conversely, in colonies with ample food reserves bees will be less responsive to these pheromones likely to save time and energy from unnecessary foraging.


B. terrestris has an impressive homing range, where bees displaced from their nests can relocate the colony from up to 9.8 km away. However, the return often takes several days, indicating B. terrestris might be utilizing familiar foliage and natural landmarks to find the nest. This may be a tedious process if an individual is outside the conventional foraging range of the nest. Another study indicated that these bees can navigate their way back to the nest from a distance as far away as 13 km (8.1 mi), although most forage within 5 km of their nest. One mark and recapture study found their average foraging distance to be approximately 663 m. Male bees have also been found to have longer flight ranges than worker bees, likely because they move farther away from the nest to find mates. Males have flight distances of anywhere from 2.6 to 9.9 km. If males also contribute to pollination, this might increase previously predicted pollen flow ranges based on worker flight behavior.


Bumblebees and honey bees are extremely influenced by an innate preference for blue and yellow color. When they have no training, they will often just visit flowers that naturally attract them. However, it is generally thought that bees will learn to visit more nectar rewarding flowers after experience associates the reward with the color of the petals. This has been demonstrated in B. terrestris, where bees trained on artificially colored flowers will pick a similar color to the one they were trained with when tested with an array of flower choices. If individuals were tested with flower colors significantly different than from what they were trained with, they just visited flowers most closely aligned with their innate color preferences. In addition to identifying specific colors for foraging purposes, it has also been shown that young worker bees have to learn complex motor skills in order to efficiently collect nectar and pollen from flowers. These skills might take several days to develop, as memory does not always hold perfectly on a day-to-day basis, sometimes deteriorating overnight. Even within a species, different populations have varying levels of innate blue preference and exhibit intraspecific variation in learning rate during association tasks. This is true of two subspecies of B. terrestris, B. terrestris dalmatinus and B. terrestris audax.


While bees are highly adept at discrimination tasks, they are still limited by the magnitude of difference needed in hue to properly carry out these tests. Error rates of color recognition decrease in B. terrestris when flower pigments are closer together on the color spectrum. This might have damaging effects on pollination efficiency if bees visit different flower species with similar, but distinct colors, which can only be mediated if the flowers have unique shapes.


While bees often forage alone, experiments demonstrate that young foragers might learn what flowers provide the most nectar more quickly when foraging with older workers. B. terrestris individuals have a faster learning curve for visiting unfamiliar, yet rewarding flowers, when they can see a conspecific foraging on the same species. The discovery of this type of associative learning is a novel insight into bee behavior and may supplement learning via color reward association.


B. terrestris is parasitized by B. bohemicus, a brood-parasitic Cuckoo bee that invades B. terrestris hives and takes over reproductive dominance from the host queen, laying its own eggs that will be cared for by host workers. Another brood parasite is the bee B. vestalis. Both of these are distributed in various regions of Europe. The difference between B. bohemicus and B. vestalis is that the former parasitizes several bumble bee species while B. vestalis exclusively parasitizes B. terrestris.


A common microsporidian parasite that infects the gut of various bumblebee species, including  B. terrestris , is Nosema bombi.  N. bombi  can cause a creeping disease and is detrimental to the fitness of its bumblebee host. A study by Manlik et al. (2017) showed that  N. bombi  infection prevalence varies widely over time, and is associated with mitochondrial DNA genotypes in  B. terrestris .


Foraging is considered energetically costly and it is possible that individuals that spend more time foraging suffer costs to their overall fitness. For example, B. terrestris is often vulnerable to parasitism by conopid flies in Central Europe, and it has been hypothesized that foragers might suffer higher incidences of parasites due to the increased metabolic costs of flying. This was demonstrated in a population in which foraging workers had significantly lower levels of encapsulation of an experimental parasitic egg when compared to non-foraging workers. This suggests that foragers have compromised immune systems due to increased energetic expenses and might be predisposed to fly parasites.


While B. terrestris is a singly mating species, a polyandrous system would potentially be beneficial because it would be possible to attain greater genetic variability for resistance against disease. Accordingly, artificially increasing the number of mates a B. terrestris queen obtains through artificial insemination has shown that the increased genetic variability in her offspring confers greater resistance to the most common bumblebee parasite, Crithidia bombi.  However, the average reproductive success between one and multiple matings is not linear. Queens that mated once and mated four times had a higher fitness than those that mated twice. This suggests that there might be a fitness barrier to increased matings, which might be why colonies are usually monandrous.


Surprisingly, the immunocompetence, as measured by the ability to encapsulate a novel antigen, does not vary based on the local environment. Experimental studies demonstrate that B. terrestris have equal levels of encapsulation in poor and stable environments. This is unexpected, because immunity should be compromised in conditions where food supply is low in order to save energy. Perhaps encapsulation represents an invariable trait of bumblebees, or immunity is far too complex to characterize solely based on measurements of encapsulation.


Deformed wing virus (DWV) is normally a honey bee pathogen that results in reduced and crumpled wings, making those individuals inviable. This virus is thought to have spread to B. terrestris, and in 2004, as many as 10% of queen bees bred commercially in Europe were found dead with deformed wings. This was confirmed as DWV when B. terrestris colonies tested positive for the presence of DWV RNA. This could indicate that DWV is a broad range pathogen among bees, or perhaps it has recently been infecting new hosts after transmission from honey bees.


While native to Europe, B. terrestris has been introduced as a greenhouse pollinator into many foreign ecosystems. The presence of B. terrestris is becoming an ecological concern in many communities in which it is not native. It is classified as an "invasive alien species" in Japan. For example, B. terrestris has a large niche overlap with local Japanese bee species in terms of flower resources and nest sites. B. terrestris queens competing for local underground nest sites are displacing B. hypocrita sapporoensis. However, B. pseudobaicalensis, which visits similar flowers but only forms nests above ground, has not seen a rapid decline in population numbers.
In 2008, the Australian government banned the live import of B. terrestris into Australia on the grounds that it would present a significant risk of becoming a feral species and thereby present a threat to native fauna and flora. In 2004, this bumblebee was classified as a 'Key Threatening Process' by the Scientific Committee of the New South Wales Department of Environment.
This species was introduced to Chile in 1998. It has since crossed into Argentina, and is spreading at about 275 km per year. Its spread has been detrimental to populations of Bombus dahlbomii, which is the only bumblebee species native to southern South America (Patagonia, Southern Chile and Argentina). Bombus terrestris populations facilitated such massive and immediate population decline of Bombus dahlbomii through competition and pathogen introduction/spillover. Bombus ruderatus, a bee previously introduced in 1982, is also seriously affected. The cause is thought to be the parasite Apicystis bombi, an organism carried by the buff-tails, but which has no adverse effect on that species.


In temperate areas, variable climates and environmental conditions occur during changing seasons. Lack of available food due to these unpredictable circumstances can often negatively affect colony growth, reproduction, and resistance to parasites. In poor environments with limited food, the few workers born are smaller than average. However, it appears that B. terrestris is well adapted to a changing environment, considering colony growth is higher under variable feeding conditions than under stable feeding conditions. Workers and reproductives are also heavier with a variable food supply when compared to stable food availability. This might indicate an adaptive strategy of increased provisioning to save for days it is hard to find food.


In their 2014 study published in Functional Ecology researchers using Radio-Frequency Identification (RFID) tagging technology on the bees, found that a sublethal exposure to either a neonicotinoid (imidacloprid) and/or a pyrethroid (?-cyhalothrin) over a four-week period caused an impairment of the bumblebee's ability to forage. Research published in 2015 showed that bees prefer solutions containing neonicotinoids, even though the consumption of these pesticides caused them to eat less food overall. This work implies that treating flowering crops with such pesticides presents a sizeable hazard to foraging bees.


Since 1987, B. terrestris has been bred commercially for use as a pollinator in European greenhouse crops, particularly tomatoes—a task which was previously carried out by human hand. B. terrestris has been commercially reared in New Zealand since the early 1990s, and is now used in at least North Africa, Japan, Korea, and Russia, with the global trade in bumblebee colonies probably exceeding 1 million nests per year. In Korea, however, some have chosen Bombus ignitus over the already established commercial pollinator, Bombus terrestris, for fear of competition or genetic contamination by mating with native bumblebee species. Also, there has been a ban on importing B. terrestris into North America which resulted in higher interest in other species like B. impatiens in North America.
Nonetheless, B. terrestris are key commercial pollinators in Europe, which has driven researchers to investigate the influence of agricultural land on the foraging and survival of this species. Monoculture reduces biodiversity in farmland areas, and likely decreases the number of flowering species bees can forage on. B. terrestris consequently exhibits greater nest growth in suburban areas than in farmland, because local suburban gardens promote more plant diversity for bees to feed from. Agriculture has a profound impact on many bumblebees, and is causing widespread decline in several species. However, B. terrestris is still widespread, likely because it can forage at very long distances, making it less sensitive to changes in biodiversity and the environment.


The half-black bumblebee (Bombus vagans) is a small bumblebee with a wide distribution in North America, its range extending from Ontario to Nova Scotia and southward to Georgia.


Bombus vagans is a common species of bumblebee with a medium-length tongue. The head, thorax and first two segments of the abdomen are yellow while the rest of the abdomen is black. The face has a mixture of yellow and black hairs and the thorax is densely clad in shaggy yellow hair except for a smooth central portion which is bare and shiny. The first two abdominal segments bear yellow hairs and the remainder of the abdomen is clad in black hairs. The underside of this bee and the legs are black. Similar species with which it can be confused include Bombus sandersoni (which is slightly smaller), Bombus perplexus, Bombus impatiens and Bombus affinis.


This bee comes out from hibernation quite late in the year with the first queens being seen in early May in Maine, and workers being on the wing from June to August. but in more southerly locations it may be seen a month earlier than this. The queen favors apple and plum blossom while the workers appreciate red clover, Penstemon, Asclepias (milkweed), Cirsium (thistle), Eupatorium and Spiraea (meadowsweet). Unlike most other species of bumblebee in the region, it forages in shady forest habitats. Drones are often to be seen late in the season on aster and goldenrod.
Nests are usually on the surface of the ground or in holes in the ground and at its peak, the colony may have about seventy workers. The nest is sometimes parasitized by the cuckoo bumblebee Bombus citrinus. The parasitic protozoon Apicystis bombi sometimes parasitizes this species.


Bombus vosnesenskii, the yellow-faced bumblebee, is a species of bumblebee native to the west coast of North America, where it is distributed from British Columbia to Baja California. It is the most abundant species of bee in this range, and can be found in both urban and agricultural areas. Additionally, B. vosnesenskii is utilized as an important pollinator in commercial agriculture, especially for greenhouse tomatoes. Though the species is not currently experiencing population decline, urbanization has affected its nesting densities, and early emergence of the B. vosnesenskii has been implicated in the increasing lack of bee diversity on the West coast.


The genus name Bombus – the bumblebee –  comes from the Latin word which means a buzzing or humming sound. There are 250 species split into 38 subgenera within the genus Bombus. These subgroups share similar morphologies, despite their varied habitats and behavioral patterns. However, many of the groups are monophyletic based on the distinct genitalia of the male bee. Genetic studies have revealed the bumblebee to be closely related to the sting-less bee and the honey bee.
Bombus vosnesenskii falls into the Bombus subgenus Pyrobombus. Bombus subgenera contain two primary morphological categories, short-faced and long-faced. Pyrobombus is included in the short-faced clade.
The subgenus Pyrobombus is both monophyletic and the largest of the subgenera.


Bombus vosnesenskii has a number of distinctive features. These include short, even hair, the rounded angle of the basitarsus, which is the middle leg, and a square face. Additionally, the fringed hair of its hind legs forms the corbicula, or pollen basket.
Queens are between 18 and 21 mm long. Workers are between 8 and 17 mm while males are between 10 and 15 mm.  Queens, workers, and males all have medium length antennae and similarly shaped and sized eyes. They are patterned with black and yellow hairs. The queen and the female workers are almost always identical in coloring. They have almost entirely black thoraxes with stripes of yellow at the head and at the T4 segment of their thorax. The male drones mostly look similar to their female counterparts, but in some cases will have more yellow on their sides that extends farther up the back of the thorax.


Although historical data for insect distribution is sparse in western North America, it is clear that Bombus vosnesenskii is not experiencing a population decline; it is amongst the most common bee species on the West Coast of the United States, and the most common bumble bee from Oregon northward. The nesting distribution ranges from British Columbia to Baja California. Historically, Bombus occidentalis, the so-called "western bumble bee" was the most common species, with a distribution all the way from California to British Columbia and Alaska, but diseases introduced by commercial rearing operations in the eastern United States brought coastal populations of B. occidentallis to the brink of extinction, and B. vosnesenskii has filled the gap. B. vosnesenskii's success in the vacuum left by B. occidentalis has not been the perfect story of nature finding balance after disturbance, however; in the San Francisco area, the frequency of B. vosnesenskii appearances to inversely correlate with the species richness of bees in the area, indicating that B. vosnesenskii outcompetes other bee species for space and resources. This may be due to the species' early emergence during the season, allowing it to overtake and monopolize available nest spaces. The bee nests underground, primarily in colony sizes of about 200-300 workers. While it is not currently in population decline, studies have shown that the B. vosnesenskii experiences reduced nesting density in urbanized landscapes. In a case study from Santa Barbara, CA - researchers found that local grassland restoration can help support provide habitat refugia for these species in urbanized areas.


Studies have demonstrated that paved environments in human urban settings have reduced B. vosnesenskii nesting densities. It is likely that this is due to the subterranean nesting habits of this bee species, which is negatively effected by the expansion of impervious substances like pavement.


Reproductive bees are raised in the last portion of B. vosnesenskii life cycle. Upon maturation, the queens will leave the nest to seek mates. They will meet with reproductive males who have left their colonies. These male bees will patrol in circuits until they encounter a suitable mate.


The queen of this bee species has been known to contribute to foraging efforts. During the early season, when the queen is young, she primarily focuses on brood incubation. However, towards the end of the season as worker numbers decline, the queen becomes a significant contributor to foraging efforts. They go so far as to become the primary pollen and nectar providers for the colony. The mechanisms behind this behavioral change are not well understood, but significance has been attributed to careful risk-balancing behaviors. The queen's efforts are much more valuable in reproduction and brood-rearing when she is young, first to build the colony, then to preserve it. There is a high risk of injury or death in foraging, which the queen offsets by allowing the worker bees to do this dangerous task. However, towards the end of the colony cycle, when the worker population has begun to dwindle, the queen is best used as a forager, to provide sustenance for the next generation of reproductive bees.


This bee species has poikilothermic eggs – they are unable to regulate their own temperature independently of the ambient temperature. However, it has been observed that egg clumps undergoing incubation are able to maintain consistent temperatures. Egg incubation is accomplished by the queen extending her abdomen out to touch the brood and make full contact, while her legs wrap around and anchor her body to the brood clump. While this position is assumed, the abdominal temperature of the queen increases greatly, and metabolism, as measured by oxygen consumption, doubles.
The incubating bees do not have a target temperature for their broods. They will continue to incubate broods despite the ambient temperature. At 30 °C, the queen will incubate the eggs, even though at 10 °C, she only raises the brood temperature to 26 °C. However, it has been observed that the amount of thermogeneration that occurs at the abdomen is reduced when the ambient temperatures are greater.
Incubating bees do not continuously warm the brood. Because of the intense metabolic cost of warming the eggs, they must occasionally take breaks to feed, at which point the brood returns to ambient temperature. Broods will hatch whether or not they have been incubated consistently, and the new worker population will assist in incubation for the next generation.


Yellow-faced bumblebees, like most bumblebees, use thermoregulation to maintain  stable body temperatures several degrees above the ambient temperature. At rest, bumblebees have temperatures close to ambient temperature. To generate power for flight, bumblebees need to raise the temperature of the flight muscles to above 30 °C (86 °F). In B. vosnesenskii, heat is transferred from the thorax to the abdomen by changes in hemolymph flow in the petiole, the narrow region between the abdomen and thorax. At low ambient temperature, the hemolymph flows from the thorax and abdomen simultaneously. As a result, the countercurrent exchange of heat in the petiole retains most of the energy in the thorax. When the ambient temperature is high, the countercurrent exchange is reduced such that heat is transferred from the thorax to the abdomen.


This bee species prefers a select set of genera for foraging purposes. These include: Lupinus, Cirsium,  Eriogonum, Phacelia,  Clarkia, and Ericameria


This bee species shows pollination preferences based on location and landscape features, as opposed to colony membership. This indicates that competition between B. vosnesenskii colonies does not drive any selective pressure in their foraging behaviors.
Additionally, the bee does not forage based on abundance or availability. There is little correlation between the most available, and the most foraged floral taxa for this species. There are some species, including the L. corniculatus, P. montana, and La. stoechas which are highly preferred by the bee despite their relatively lower abundances. Again, these ranked preferences are similar between bees that share regions, as opposed to individual bees and their colony-mates.
The yellow-faced bumblebee appears to select its foraging locations based on the diversity of available flora in a given region, as opposed to floral density. This means that the bees are willing to travel longer distances to forage from patches that have wider varieties of available floral taxa. A possible explanation for this behavior is a necessity by the bee to increase the variety of nutrients it intakes by diversifying its nectar consumption. Additionally, bees which develop preferences for varied plant genera are likely to have more stable food resources over long periods of time.


Bombus vosnesenskii is an extremely important pollinator for commercial agriculture. The genus Bombus is the primary pollinator for greenhouse tomatoes.
While the mechanisms are not well understood, B. vosnesenskii pollinates greenhouse tomatoes more efficiently than human beings are capable of simulating by hand. On several measures, including fruit weight, height, minimum and maximum diameter, grade, and seed count, bee-pollinated fruits are of significantly higher quality. One theory suggests that bees are able to time their visits better than humans, who typically adhere to a set schedule which may not coincide with floral receptivity.


For the Bombus vosnesenskii, parasitic organisms include the phoretic mite species Kuzinia and the protozoan Crithidia bombi. Both of these parasites affect individual bees rather than colonies or nests, and have been discovered in relatively high abundance in the Californian B. vosnesenskii population. Both of these parasites have been discovered in several bees of the Bombus genus, and display a relatively low level of host specificity. Apicystis bombi has also been observed, but at low abundance. Alone, it is unlikely that these parasites can cause severe decline or extinctions in bee populations; however, compounded with other stresses, they can be implicated in the decline of species' health.


The Bohemian waxwing (Bombycilla garrulus) is a starling-sized passerine bird that breeds in the northern forests of the Palearctic and North America. It has mainly buff-grey plumage, black face markings and a pointed crest. Its wings are patterned with white and bright yellow, and some feather tips have the red waxy appearance that give this species its English name. The three subspecies show only minor differences in appearance. Females are similar to males, although young birds are less well-marked and have few or no waxy wingtips. Although the Bohemian waxwing's range overlaps those of the cedar and Japanese waxwings, it is easily distinguished from them by size and plumage differences.
The breeding habitat is coniferous forests, usually near water. The pair build a lined cup-shaped nest in a tree or bush, often close to the trunk. The clutch of 3–7 eggs is incubated by the female alone for 13–14 days to hatching. The chicks are altricial and naked, and are fed by both parents, initially mostly with insects, but thereafter mainly fruit. They fledge about 14–16 days after leaving the egg. Many birds desert their nesting range in winter and migrate farther south. In some years, large numbers of Bohemian waxwings irrupt well beyond their normal winter range in search of the fruit that makes up most of their diet.
Waxwings can be very tame in winter, entering towns and gardens in search of food, rowan berries being a particular favourite. They can metabolise alcohol produced in fermenting fruit, but can still become intoxicated, sometimes fatally. Other hazards include predation by birds of prey, infestation by parasites and collisions with cars or windows. The Bohemian waxwing's high numbers and very large breeding area mean that it is classified as being of least concern by the International Union for Conservation of Nature.


The waxwings are a family, Bombycillidae, of short-tailed stocky birds with soft plumage, a head crest and distinctively patterned wings and tails. There are three species, the Bohemian, cedar, and Japanese waxwings. DNA studies and shared features such as a relatively large size, grey underparts and similar undertail patterns suggest that the Japanese and Bohemian waxwings are most closely related within the genus. Although only the cedar and Bohemian waxwings normally have red tips on their wing feathers, this feature is occasionally shown by the Japanese waxwing, suggesting that this was originally a whole-family characteristic that has been lost in one species, rather than an indicator of a close relationship. DNA analysis confirms that the cedar waxwing diverged early from the other members of the family. Outside the genus, the closest relatives of the waxwings are believed to be the silky-flycatchers, the palmchat, and the grey hypocolius, all of which have sometimes been included in the Bombycillidae.
The Bohemian waxwing was described by Carl Linnaeus in his 1758 10th edition of Systema Naturae as Lanius Garrulus. The waxwings were moved to their own genus, Bombycilla, by Louis Jean Pierre Vieillot in 1808. The genus name Bombycilla comes from the Greek bombux, "silk" and the Modern Latin cilla, "tail"; this is a direct translation of the German Seidenschwanz, "silk-tail", and refers to the silky-soft plumage of the bird. The species name garrulus is the Latin for talkative and was applied to this bird, as "Garrulus Bohemicus", by Conrad Gessner in 1555; the term is a reference to a supposed likeness to the Eurasian jay (Garrulus glandarius) rather than to the waxwing's vocalisations. The English name "waxwing" refers to the bright red tips of the secondary feathers on its wings, which look like drops of sealing wax, while "Bohemian" follows Gessner's usage, and may refer to the Romani, alluding to the bird's wanderings, or to its presumed origin from Bohemia. "Waxwing" and "Bohemian waxwing" were first recorded in 1817, the former as a reference to Vieillot's separation of this bird from the "chatterers".
There are three recognised subspecies:
B. g. garrulus (Linnaeus, 1758): the nominate subspecies, breeds in northern Europe from northern Sweden east to the Ural Mountains.
B. g. centralasiae (Poliakov, 1915): breeds from the Urals eastwards across northern Asia.
B. g. pallidiceps (Reichenow, 1908): breeds in northwestern North America.
The differences between these forms are small and clinal, and the species could be possibly considered as monotypic. The fossil record includes Pleistocene deposits from the UK and the Carpathian Mountains.


The Bohemian waxwing is a starling-sized bird 19–23 cm (7.5–9.1 in) in length with a 32–35.5 cm (12.6–14.0 in) wingspan, and an average weight of 55 g (1.9 oz). It is short-tailed, mainly brownish-grey, and has a conspicuous crest on its head. The male of the nominate subspecies has a black mask through the eye and a black throat. There is a white streak behind the bill and a white curve below the eye. The lower belly is a rich chestnut colour and there are cinnamon-coloured areas around the mask. The rump is grey and the tail ends in a bright yellow band with a broad black border above it. The wings are very distinctive; the flight feathers are black and the primaries have markings that produce a yellow stripe and white "fishhooks" on the closed wing. The adult's secondaries end in long red appendages with the sealing wax appearance that gives the bird its English name. The eyes are dark brown, the bill is mainly black, and the legs are dark grey or black. In flight, the waxwing's large flocks, long wings and short tail give some resemblance to the common starling, and its flight is similarly fast and direct. It clambers easily through bushes and trees but only shuffles on the ground.
The soft, dense feathers are kept in good condition by preening. The red waxy tips are the extended and flattened ends of feather shafts, pigmented with astaxanthin and enclosed in a transparent sheath. A study of the cedar waxwings showed that the red tips are few or absent until the third year of life for that related species. All adult waxwings have a complete moult annually between August and January. Juveniles moult at the same time but retain their flight and some other wing feathers.
The female Bohemian waxwing is very similar to the male, but has a narrower yellow terminal band to the tail, a less defined lower edge to the black throat and slightly less distinctive wing markings. Juveniles are duller than adults, with whiter underparts, only a few red wing tips, no black on the throat and a smaller black face mask. Compared to the nominate subspecies, eastern B. g. centralasiae is paler, greyer and has little reddish-brown behind the bill. The American subspecies B. g. pallidiceps has more colouring on the cheeks and forehead than the nominate form and is otherwise generally duller in appearance.
The range of the Bohemian waxwing overlaps those of both the other members of the genus. The cedar waxwing is smaller than the Bohemian; it has browner upperparts, a white undertail and a white line above the black eye patch. Adult cedar waxwings have a yellowish belly, and all ages have less strongly patterned wings than the Bohemian waxwing. The Japanese waxwing is easily distinguished from its relatives; it has a red terminal band to the tail, the black mask extends up the rear of the crest, and there is no yellow stripe or red tips on the wings.
The Bohemian waxwing's call is a high trill sirrrr. It is less wavering and lower-pitched than that of the cedar waxwing, and longer and lower-pitched than the call of the Japanese waxwing. Other calls are just variants of the main vocalisation; a quieter version is used by chicks to call parents, and courtship calls, also given during nest construction, have a particularly large frequency range. Although not a call as such, when a flock takes off or lands, the wings make a distinctive rattling sound that can be heard 30 m (98 ft) away.


The Bohemian waxwing has a circumpolar distribution, breeding in northern regions of Eurasia and North America. In Eurasia, its northern nesting limit is just short of the treeline, roughly at the 10 °C July isotherm, and it breeds south locally to about 51°N. Most birds breed between 60–67°N, reaching 70°N in Scandinavia. The North American subspecies breeds in the northwestern and north central areas of the continent, its range extending southwards beyond the US border in the Rocky Mountains.
This waxwing is migratory with much of the breeding range abandoned as the birds move south for the winter. Migration starts in September in the north of the range, a month or so later farther south. Eurasian birds normally winter from eastern Britain through northern parts of western and central Europe, Ukraine, Kazakhstan and northern China to Japan. North American breeders have a more southeasterly trend, many birds wintering in southeast Canada, with smaller numbers in the north central and northeastern US states. Birds do not usually return to the same wintering sites in successive years. One bird wintering in the Ukraine was found 6,000 km (3,700 mi) to the east in Siberia in the following year.
In some years, this waxwing irrupts south of its normal wintering areas, sometimes in huge numbers. The fruit on which the birds depend in winter varies in abundance from year to year, and in poor years, particularly those following a good crop the previous year, the flocks move farther south until they reach adequate supplies. They will stay until the food runs out and move on again. In what may be the largest ever irruption in Europe, in the winter of 2004–2005, more than half a million waxwings were recorded in Germany alone. This invasion followed an unusually warm, dry breeding season. In 1908, an American flock 60–90 m (200–300 ft) wide was noted as taking two to three minutes to fly over.
The breeding habitat is mature conifers, often spruce although other conifers and broadleaf trees may also be present. More open, wet areas such as lakes and peat swamps with dead and drowned trees are used for feeding on insects. Lowlands, valleys and uplands are used in Eurasia, although mountains tend to be avoided. However, the North American subspecies nests in Canada at altitudes between 900–1,550 m (2,950–5,090 ft). Outside the breeding season, the waxwing will occupy a wide range of habitats as long as suitable fruits such as rowan are available. It may be found by roads, in parks and gardens or along hedges or woodlands edges. It shows little fear of humans at this time. In winter, waxwings roost communally in dense trees or hedges, sometimes with American robins, fieldfares or other wintering species.


Bohemian waxwings start their return from the wintering grounds in February or March, but northern breeders do not reach their breeding areas until April or early May. This monogamous species nests mainly from mid-June to July.
Waxwings are not highly territorial, and, although normally solitary breeders, several pairs may nest close together where there are a number of good nest sites. Males may sometimes deter rivals from approaching their mates, and females may squabble over nest sites. Aggression is shown by sleeking down the feathers and crest, showing the black throat, and opening the bill. The breeding display is almost the opposite of this; the male erects his body and crest feathers, and turns his head away from the female. The male may repeatedly present a gift of a small item, often food, to his partner, placing it in her open bill. In about 90% of cases, this display does not lead to copulation. Older males have more red tips to the wings and are preferred by females.
The nest, built by both sexes, is a cup of thin twigs lined with softer material such as fine grass, moss, fur or lichen. It is constructed 1.3–15 m (4–50 ft) above the ground in a pine or scrub, commonly close to the trunk. The eggs are a glossy pale blue spotted with black and grey and the clutch is 3–7 eggs, although five or six is most common. The average size of the egg is 24 mm × 18 mm (0.94 in × 0.71 in), and it weighs 3.8 g (0.13 oz), of which 5% is shell. The eggs are incubated for 13–14 days by the female alone. She is fed regurgitated berries by her mate, and rarely leaves the nest. The chicks are altricial and naked, and have bright red mouths; they are fed by both parents, although the male brings most of the food, mainly insects, in the first few days. The young are subsequently fed largely with fruit. The chicks fledge about 14–16 days after hatching. They are fed by the adults for about two weeks after fledging.
Breeding densities of this waxwing are typically low compared to other passerines, usually less than ten birds per square kilometre (26 per square mile) even in good habitat, although up to 35·6 birds per square kilometre (92 per square mile) have been found in Russia. One brood each year is normal. Maximum recorded ages are 5 years 10 months in North America and more than 13 years 6 months in Europe. The average life expectancy is unknown. Significant causes of death include predation, collisions with windows and cars, and poisoning by road salt consumed when drinking.


Waxwings are primarily fruit eaters, but also consume insects during the breeding season. Mosquitoes and midges are the most common prey, but many other insects and some spiders are eaten. They are caught mainly by flycatching from an open perch, but some may be picked off vegetation. Fruit is normally picked from trees, sometimes from the ground, and is usually swallowed whole. In the summer, Vaccinium and Rubus species and Canada buffaloberry are important items of their diet, while cotoneaster, juniper, haws, rose hips and apples predominate outside the breeding season. Rowan berries are a favourite food, and are eaten whenever available.
Waxwings can eat huge numbers of berries, each bird sometimes consuming several hundred a day, more than double its own weight. One individual was recorded as eating between 600 and 1,000 cotoneaster berries in six hours, and defecating every four minutes. Waxwings travel significant distances when feeding and help to disperse the fruit seeds. Waxwings forage in large flocks, sometimes of several hundred birds, which enables them to overwhelm birds such as mistle thrushes attempting to defend their fruit trees.
Fruit is rich in sugar but deficient in other nutrients, so it must be eaten in large quantities. Bohemian waxwings have a large liver which helps to convert sugar to energy. They can metabolise ethanol produced from the fermentation of those sugary fruits more efficiently than humans, but may still become intoxicated, sometimes fatally. Waxwings often drink water or eat snow in winter, since the sugar in their fruit diet tends to dehydrate the birds through an osmotic effect. In the summer, the fruits are juicier and water is less of a problem.
In the past, the arrival of waxwings sometimes coincided with epidemics of cholera or plague, and led to the old Dutch and Flemish name Pestvogel, "plague bird". The juniper berries on which they fed were thought to offer protection, and people consumed the fruit and burned branches to fumigate their houses.


Waxwings are preyed upon by birds of prey including rough-legged buzzards, Eurasian sparrowhawks, prairie falcons, and great grey shrikes. Merlins attack winter flocks, including those in cities. When alarmed, Bohemian waxwings "freeze" with bill and neck pointing upwards. If this fails, they fly, calling noisily.
Bohemian waxwings are not brood parasitised by the common cuckoo or its relatives in Eurasia because the cuckoo's young cannot survive on a largely fruit diet. In North America, the waxwing's breeding range has little overlap with brown-headed cowbird, another parasitic species. Nevertheless, eggs of other birds placed in a Bohemian waxwing's nest are always rejected. This suggests that in the past, perhaps 3 million years ago, the ancestral waxwing was a host of a brood parasitic species, and retains the rejection behaviour acquired then.
Parasitic mites include Syringophiloidus bombycillae, first identified on this species, and the nasal mite Ptilonyssus bombycillae. Blood parasites include Trypanosoma species, and a Leucocytozoon first identified in this waxwing. Bohemian waxwings may carry flatworms and tapeworms, but levels of parasitic worm infestation are generally low.


The global population of the Bohemian waxwing has been estimated at more than three million birds, and the breeding range covers about 12.8 million km² (4.9 million mi²). Although this species' population, as of 2013, appears to be declining, the decrease is not rapid nor large enough to trigger conservation vulnerability criteria. Given its high numbers and huge breeding area, this waxwing is therefore classified by the International Union for Conservation of Nature as being of least concern.  The woodlands used by this species are well to the north of major human populations, and the birds can use disturbed habitats, so there are no serious long-term threats to this species.


The ruffed grouse (Bonasa umbellus) is a medium-sized grouse occurring in forests from the Appalachian Mountains across Canada to Alaska. It is the most widely distributed game bird in North America. It is non-migratory. It is the only species in the genus Bonasa.
The ruffed grouse is sometimes incorrectly referred to as a "partridge", an unrelated phasianid, and occasionally confused with the grey partridge, a bird of open areas rather than woodlands.
The ruffed grouse is the state bird of Pennsylvania, United States.


Bonasa umbellus was first described by Carl Linnaeus in his 1766 12th edition of Systema Naturae. He classified it as Tetrao umbellus, placing it in a subfamily with Eurasian grouse. The genus Bonasa was applied by British naturalist John Francis Stephens in 1819. Ruffed grouse is the preferred common name because it applies only to this species. Misleading vernacular names abound, however, and it is often called partridge (sometimes rendered pa'tridge, or shortened to pat), pheasant, or prairie chicken, all of which are properly applied to other birds. Other nicknames for ruffed grouse include drummer or thunder-chicken.
There are 14 recognized subspecies of ruffed grouse:
B. u. yukonensis Grinnell, 1916
B. u. umbelloides (Douglas, 1829)
B. u. labradorensis Ouellet, 1991
B. u. castanea Aldrich & Friedmann, 1943
B. u. affinis Aldrich & Friedmann, 1943
B. u. obscura Todd, 1947
B. u. sabini (Douglas, 1829)
B. u. brunnescens Conover, 1935
B. u. togata (Linnaeus, 1766)
B. u. mediana Todd, 1940
B. u. phaios Aldrich & Friedmann, 1943
B. u. incana Aldrich & Friedmann, 1943
B. u. monticola Todd, 1940
B. u. umbellus (Linnaeus, 1766)


Ruffed grouse are chunky, medium-sized birds that weigh from 450–750 g (0.99–1.65 lb), measure from 40 to 50 cm (16 to 20 in) in length and span 50–64 cm (20–25 in) across their short, strong wings. They have two distinct morphs: grey and brown. In the grey morph, the head, neck, and back are grey-brown; the breast is light with barring. There is much white on the underside and flanks. Overall, the birds have a variegated appearance; the throat is often distinctly lighter. The tail is essentially the same brownish grey, with regular barring and a broad black band near the end ("subterminal"). Brown-morph birds have tails of the same color and pattern. However, the rest of the plumage is much more brown, giving the appearance of a more uniform bird with less light plumage below and a conspicuously grey tail. There are all sorts of intergrades between the most typical morphs; warmer and more humid conditions favor browner birds in general.
The ruffs are on the sides of the neck in both sexes. They also have a crest on top of their head, which sometimes lies flat. Both sexes are similarly marked and sized, making them difficult to tell apart, even in hand. The female often has a broken subterminal tail band. At the same time, males tend to have unbroken tail bands, though the opposite of either can occur. Females may also do a display similar to the male. Another fairly accurate sign is that rump feathers with a single white dot indicate a female; rump feathers with more than one white dot indicate a male.
The average life span of a ruffed grouse is one year, although some birds are thought to live for as long as eleven years. Ruffed grouse are polygynous, and males may mate with several females during the breeding season.


Like most grouse, they spend most of their time on the ground; mixed woodland rich in aspen seems to be particularly well-liked. These birds forage on the ground or in trees. They are omnivores, eating buds, leaves, berries, seeds, and insects. According to nature writer Don L. Johnson:
More than any other characteristic, it is the ruffed grouse's ability to thrive on a wide range of foods that has allowed it to adapt to such a wide and varied range of habitat on this continent. A complete menu of grouse fare might itself fill a book. One grouse crop yielded a live salamander in a salad of watercress. Another contained a small snake.


Hunting of the ruffed grouse is common in the northern and far western United States as well as Canada, often with shotguns. Dogs may also be used. Hunting of the ruffed grouse can be challenging. This is because the grouse spends most of its time in thick brush, aspen stands, and second growth pines. It is also very hard to detect a foraging grouse bobbing about in the thicket due to their camouflage. With adequate snow cover, they will burrow under the snow. The ruffed grouse will maintain trails through the underbrush and pines like other forest creatures. These can often be found by looking for the bird's feathers on the ground and twigs at the edges of its trail. Hunting of the ruffed grouse requires a good ear and lots of stamina as one will be constantly walking and listening for them in the leaves.
— Joseph B. Barney
Ruffed grouse frequently seek gravel and clover along road beds during early morning and late afternoon. These are good areas to walk during this time to flush birds. Also, grouse use sandy roadbeds to dust their feathers to rid themselves of skin pests. Dusting sites are visible as areas of disturbed soils with some signs of feathers. Birds will return to these spots during the late afternoon to bathe in dust and socialize and mate.
Minnesota is the top ruffed grouse–producing state in the U.S.


Borage (/ˈbʌrɪdʒ/ (listen) or /ˈbɒrɪdʒ/; Borago officinalis), also known as starflower, is an annual herb in the flowering plant family Boraginaceae. It is native to the Mediterranean region, and has naturalized in many other locales.
It grows satisfactorily in gardens in most of Europe, such as Denmark, France, Germany, and the United Kingdom, remaining in the garden from year to year by self-seeding. The leaves are edible and the plant is grown in gardens for that purpose in some parts of Europe.
The plant is also commercially cultivated for borage seed oil extracted from its seeds.
The plant contains pyrrolizidine alkaloids, some of which are hepatotoxic, mutagenic, and carcinogenic (see below under Phytochemistry).


B. officinalis grows to a height of 60–100 cm (2 ft 0 in – 3 ft 3 in), and is bristly or hairy all over the stems and leaves; the leaves are alternate, simple, and 5–15 cm (2–6 in) long.
The flowers are complete, perfect with five narrow, triangular-pointed petals. Flowers are most often blue, although pink flowers are sometimes observed. White-flowered types are also cultivated. The blue flower is genetically dominant over the white flower.
The flowers arise along scorpioid cymes to form large floral displays with multiple flowers blooming simultaneously, suggesting that borage has a high degree of geitonogamy (intraplant pollination).
It has an indeterminate growth habit, which may lead to prolific spreading. In temperate climates such as in the UK, its flowering season is relatively long, from June to September. In milder climates, borage blooms continuously for most of the year.


Traditionally, borage was cultivated for culinary and medicinal uses, although today, commercial cultivation is mainly as an oilseed.
Borage is used as either a fresh vegetable or a dried herb. As a fresh vegetable, borage, with a cucumber-like taste, is often used in salads or as a garnish.
The flower has a sweet, honey-like taste and is often used to decorate desserts and cocktails, most commonly, frozen in ice cubes.


Vegetable use of borage is common in Germany, in the Spanish regions of Aragón and Navarre, on the Greek island of Crete, and in the northern Italian region of Liguria.
Although often used in soups, one of the better known German borage recipes is the Frankfurt speciality grüne Soße ("green sauce").
In Liguria, Italy, borage (in Italian, borragine) is commonly used as a filling of the traditional pasta ravioli and pansoti.
It is used to flavour pickled gherkins in Poland and Russia.
The flowers produce copious nectar which is used by honeybees to make a light and delicate honey.


Borage is traditionally used as a garnish in the Pimms Cup cocktail, but is nowadays often replaced by a long sliver of cucumber peel or by  mint. It is also one of the key botanicals in Gilpin's Westmorland Extra Dry Gin.
In Persian cuisine, borage tea (using the dried purple flowers) is called گل گاوزبان : gol gâvzabân, "cow's-tongue-flower".


The seeds contain 26–38% of borage seed oil, of which 17–28% is gamma-linolenic acid (GLA, an Omega-6 oil), the richest known source.
The oil also contains the fatty acids palmitic acid (10–11%), stearic acid (3.5–4.5%), oleic acid (16–20%), linoleic acid (35–38%), eicosenoic acid (3.5–5.5%), erucic acid (1.5–3.5%), and nervonic acid (1.5%).
The oil is often marketed as "starflower oil" or "borage oil" for use as a GLA supplement, although healthy adults typically produce ample GLA from dietary linoleic acid.
The leaves contain small amounts (2–10 ppm of dried herb) of the liver-toxic pyrrolizidine alkaloids (PA) intermedine, lycopsamine, amabiline, and supinine and the nontoxic saturated PA thesinine.  PAs are also present in borage seed oil, but may be removed by processing.
The German Federal Institute for Risk Assessment has advised that honey from borage contains PAs, transferred to the honey through pollen collected at borage plants, and advise that commercial honey production could select for raw honey with limited PA content to prevent contamination.


Traditionally, Borago officinalis has been used in hyperactive gastrointestinal, respiratory and cardiovascular disorders, such as gastrointestinal (colic, cramps, diarrhea), airways (asthma, bronchitis), cardiovascular, (cardiotonic, antihypertensive and blood purifier), urinary (diuretic and kidney/bladder disorders).
One case of status epilepticus has been reported that was associated with borage oil ingestion.
A methanol extract of borage has shown strong amoebicidal activity in vitro. The 50% inhibitory concentration (LD₅₀) of the extract against Entamoeba histolytica was 33 µg/mLl.