Killer bees are among the most notorious insects out there. Even their name sounds very threatening. Many people first hear about them from stories about massive deadly attacks or horrific depictions present in popular culture, like in the movie the Swarm. But what exactly are killer bees and what makes them so deadly? Are they really that dangerous? Today, we compare killer bees with other kinds of bees and wasps to see if killer bees are really the most dangerous.
But first, let’s answer the basic question, what exactly are killer bees? Killer bees are also called Africanized bees, and they are actually very close cousins of regular honey bees. Their ancestors were not really that special either. Namely, Africanized bees are a hybrid of the western honey bee. What is means is that they were made by combining two subspecies of the western honey bee – the African bee (East African lowland honey bee, more precisely) and the European honey bee. Neither of these species was especially dangerous on its own.
So what made killer bees so dangerous and aggressive? Well, that’s the thing with hybrids. A hybrid is the offspring of two different species, and what we might expect as a result of such practice is for the offspring to have a combination of features from the two species. However, in some cases hybrids can have biological characteristics that go far beyond those of either of the parents. This is a known phenomenon in biology, called hybrid vigor or heterosis. And it is exactly what happened with killer bees.
Namely, killer bees have quite an interesting origin story. During the 1950s, a Brazilian biologist was experimenting with interbreeding European and African honey bees, in an attempt to create a species that will be more resilient and produce more honey. Long story short, in 1957, 28 swarms of Africanized honey bees got accidentally released into the wild. After the release, these swarms started to spread across Africa, cross-breeding with the local honey bee colonies. They have reached South America in the 1970s and spread to the United States during the 90s thus becoming one of the most invasive species ever.
But how dangerous is the attack of the killer bees? How does it compare to regular honey bees? And what about yellow jackets and hornets? Let’s find out!
Killer Bees vs Honey Bees
Africanized bees, or killer bees, don’t look much different from regular honey bees. The main difference, in terms of appearance, between regular European honey bees and Africanized honey bees is the size and killer bees are actually a little bit smaller. However, the difference in size is only about 10%. Killer bees are also usually a little bit darker. These differences are really subtle, though, so it’s basically impossible to distinguish between the two without precise measurements and testing.
So, killer bees look almost the same as regular honey bees, but is their sting more venomous? It turns out it actually isn’t. The killer bees’ venom is actually the same as the one found in European honey bees. Moreover, because they are slightly smaller, killer bees actually have a little less venom, in theory. Just like all honey bees, Africanized bees also have a barbed sting, which means they can only sting once. After they sting you, they will die.
Which One Is More Dangerous?
Even though the killer bees look the same and essentially sting the same as European honey bees, there is another important difference between the two. It’s their behavior. In fact, it is the strong defensive response that has earned Africanized bees the nickname “killer bees”.
So what is it all about? European honey bees tend to only sting a human (or anything else) if they perceive it as a threat. Individual bees are generally not very easily provoked. On the other hand, in honey bee colonies, some workers are usually placed outside the hive to guard it. If they perceive a threat, the guards start releasing an alarm pheromone that attracts more worker bees to the location.
The defense system of Africanized honey bees works just about the same, but it can often have much more serious consequences. Why is that? It’s because Africanized honey bees have a much stronger defensive response to perceived threats. It’s much easier to provoke killer bees, and they tend to respond much more quickly. Not only this, but they also attack in greater numbers. Another peculiar feature of killer bees, and probably the one that makes them so scary, is the fact that once they start attacking, they can chase their targets to extremely long distances. This is something European honey bees don’t do.
For example, the scientist from the United States Department of Agriculture conducted a study in which they compared the defensive responses of European honey bees and Africanized honey bees. In two separate experiments, they measured the number of stings the colonies impacted on the target. In the case of Africanized bees, this number was 8.2 times higher in the first experiment, and 5.9 times higher in the second. This is not only because killer bees attack in greater number, but each of them is also much more likely to sting the target.
In conclusion, killer bees look just like regular honey bees to the naked eye. If undisturbed, they also behave the same way. No, they don’t go actively looking for human targets, but if you disturb a colony of killer bees and become their target, you’ll have a much bigger problem than with regular honey bees.
Killer Bees Actually Attack Regular Honey Bees
Killer bees are not only the slightly more ferocious cousins of European honey bees. Namely, killer bees are also capable of invading and taking over existing colonies of European honey bees. In fact, Africanized honey bees have been spreading at an unprecedented rate throughout the American continent over the last 60 years. A study conducted in Arizona in 2004 has shown that swarms of Africanized honey bees can attack weak colonies of European honey bees, kill the queen and take the hive over.
Killer Bees vs Carpenter Bees
Carpenter bees are quite similar to bumble bees, which is why people often confuse the two. Carpenter bees can be about the same size as killer bees and honey bees, but they can also be twice as large, depending on the species in question. What distinguishes carpenter bees in terms of appearance is their black, hairless abdomen (both honey bees and bumblebees have abdomens covered with tiny hairs, but not carpenter bees). They are usually mostly black, while parts of their thorax can be yellow.
Both in Africanized honey bee colonies and in carpenter bee colonies, only females are able to sting. While male killer bees generally don’t attack, male carpenter bees do exhibit defensive behavior. However, since they are unable to sting, all they can do is fly towards the threat (which might be you). Though this can look quite scary, as carpenter bees can be quite large, male carpenter bees are actually harmless.
But what about the females? Carpenter bees actually have one advantage over killer bees when it comes to stinging. Namely, the sting of a carpenter bee isn’t barbed, like those of the honey bees, but smooth, which means that a carpenter bee can sting multiple times.
Which One Is More Dangerous?
If we would compare a single carpenter bee and a single killer bee, the carpenter bee would be more dangerous as it can sting you multiple times while a killer bee stings only once and then dies. However, the strength of the killer bees is in numbers and persistence, which is why they are much more dangerous than carpenter bees. Carpenter bees are much less defensive than killer bees and will generally not attack unless you are messing with their nest. With that being said, carpenter bee colonies can grow rather large and they are notorious for damaging wood and wooden structures in which they build their nests. However, in terms of danger to humans, killer bees definitely win.
Killer Bees vs Yellow Jackets
The family of wasps includes a wide variety of species, some of which are solitary and some of which have colonies somewhat similar to honey bees, but the yellow jackets are probably the most common and well-known type of wasp out there. In terms of appearance, yellow jackets can sometimes be mistaken with bees. They are roughly the same size as regular honey bees and killer bees. The color is quite similar too – a combination of black and yellow. However, the two species differ in terms of how their body is shaped. Another distinguishing feature of yellow jacket is the fact that, unlike bees, they have a smooth body and legs.
Although both live in colonies, yellow jackets and killer bees make nests that are quite different. Wasps don’t have wax glands like bees, so they build their nests out of plant fiber mixed with saliva. Some species of yellow jackets build their nests out in the open, while others prefer to build them in the ground.
While both killer bees and yellow jackets have stings and attack their threats in a similar way, the two are actually quite different. As we have mentioned, a killer bee only stings once and dies after stinging. Yellow jackets, on the other hand, can sting indefinitely and bite as well. Even though they can bite, what hurts is their sting. Moreover, yellow jackets are not only capable of stinging multiple times, but will do so in most cases once they have set their sight on a target.
Both killer bees and yellow jackets have venomous stings which produce similar effects in humans. However, their venoms are different in terms of chemical structure. This is why some people can be allergic to venom coming from one of those insects, but not the other. Another difference between the two stings is the amount of venom that gets injected into the target. When a killer bee stings, she injects approximately 50 micrograms of poison, while in yellow jackets the amount of venom per sting is usually between 2 and 15 micrograms.
Which One Is More Dangerous?
Again, if we compared one killer bee and one yellow jacket, the yellow jacket would have the advantage of being able to sting multiple times. On the other hand, the killer bee’s one sting would be somewhat stronger. However, the real strength of both of these insects is in numbers.
Similar to killer bees, yellow jackets tend to get defensive if you come close to their nests. Yellow jackets also tend to build their nests in spaces close to our homes, so in this respect they could be considered slightly more dangerous. That is, there is a higher chance that a human will accidentally stumble upon a yellow jacket nest than a colony of killer bees.
However, yellow jacket attacks are almost never deadly. The only people who are at risk are those that are allergic to the venom of yellow jackets in which case severe allergic reactions can occur. Yellow jackets are also more likely to attack for no apparent reason. On the other hand, killer bees are still more aggressive than yellow jackets and will chase their target further. In short, killer bees are more deadly than yellow jackets – in most cases, that is.
Killer Bees vs Hornets
The name “hornet” refers to all of the insects that belong to the genus called Vespa, so there are 22 different species of hornets known worldwide. However, if you don’t live in the tropics of Asia, you are most likely to encounter the European hornet (Vespa crabro). In fact, the European hornet is what most of us are thinking about when we say hornet. European hornets look pretty much like enlarged yellow jackets. They are usually about twice the size of a honey bee. However, some hornet species can reach up to 2.2 inches in length, which is almost five times the size of a killer bee.
Just like wasps, hornets are able to pull out their stinger after stinging, which means they can do it multiple times. The venom of the hornet’s sting is similar to that of smaller wasps, but it’s injected in larger quantities simply due to the size of the hornet. Hornet stings are very painful to humans, but usually not too dangerous. If you are allergic to the venom, though, getting stung by a hornet becomes a much bigger problem. In any case, cases where stings from European hornets require medical attention are quite rare.
On the other hand, as there are different species of hornets, the level of danger depends on the species of hornet you are dealing with. The Asian giant hornet is the biggest and most dangerous kind of hornet. The sting of Asian giant hornet alone is 6 mm long. Their venom is also extremely toxic, so much so that it can kill people, even those that are not allergic to the venom. One sting by Asian giant hornet is not lethal, but multiple stings can lead to complications and death.
Which One Is More Dangerous?
If one would have to choose whether to be attacked by killer bees or hornets, it would certainly not be an easy choice. Just like bees, hornets live in colonies. They also possess an alarm pheromone that can attract more hornets once they identify a threat.
A single sting from the hornet is more painful than that of the killer bee. However, hornets are not as aggressive and easily provoked as killer bees. If we are talking about European hornet, their attacks are generally less dangerous for humans than those of killer bees. However, if we are talking about the Asian giant hornet, the biggest hornet out there and one of the most poisonous insects, we would say it’s definitely more dangerous, and scary, than killer bees.
BBC Earth: Are “killer” Africanized bees really that dangerous?
Colony Defense by Africanized and European Honey Bees
M. K. O’Malley, J. D. Ellis, and C. M. Zettel Nalen: Differences Between European and African Honey Bees
Jon F. Harrison, Jennifer H. Fewell, Kirk E. Anderson, Gerald M. Loper, Environmental physiology of the invasion of the Americas by Africanized honeybees, Integrative and Comparative Biology, Volume 46, Issue 6, December 2006, Pages 1110–1122, https://doi.org/10.1093/icb/icl046
Bee Health: Africanized Bees: Better Understanding, Better Prepared
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John Swain: How do bee and wasp stings differ?