Anyone watching the news for reports of Asian hornets arriving in the British Isles might have vague memories about previous potential invasions of killer bees. They may even have seen some pretty dire horror B movies like The Swarm (1978), or Killer Bees (2002). Could these terrors really arrive?
Bees sting. It’s part of their nature and the sting in the tail is an allure that has played an important role in bee romanticisation over the centuries. Honeybees use their stings to protect their large colonies from all manner of dangerous raiders — badgers, bears, wasps, and other colonies of bees.
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Honey is their winter store, a concentrated energy-rich foodstuff to see them through a period where there are no flowers, no nectar, so no food.
When humans started harvesting honey, they too were simply predators — destroying the wild bee colonies to get at the rich honeycombs. But with a shift to fixed agriculture some 12,000-10,000 years ago, hunting/gathering became old hat, and honeybees started to be kept in permanent fashion by humans — first in clay pipes, then hollow logs, woven skeps and finally wooden hives.
But the bees still stung. Harvesting the honey was a painful and potentially dangerous, business. So as with their other domesticated animals, humans started to selectively breed bees to get more honey from more docile bees.
This reached its zenith in the 19th century with the development of modern wooden hives with removable wooden frames for the combs, and also an understanding of genetics. Beekeepers could selectively increase yields from rather passive bees, which were easy to contain, and control and ship about.
This came with a downside though — a shallow genetic make up for the world’s dominant bee strains. Diseases, parasites and pests ran rife. At the beginning of the 20th century the Isle of Wight disease (a mite infestation in the honeybee breathing tubes) is reckoned to have destroyed the entire population of the then standard British ‘black’ bees (Apis mellifera subspecies mellifera), which were subsequently replaced with the orange and brown bees from eastern Europe (subspecies carnica) and Italy (subspecies ligustica) that we have today.
What is the Africanised bee?
During the 1950s a South American beekeeper was trying to breed a strain of honeybees that did better in the tropical climate of Brazil, than did the mollycoddled descendants of the European bees that had dominated the trade the world over. In an attempt to get some wild nous back into his honeybee stocks, he was crossing them with an African subspecies (scutellata) from Tanganyika, which was more aggressive, but better suited to tropical conditions.
Their aggression was linked to their defensive nature which did not just mean fighting off nest intruders, but also cleanliness in the hive, resistance to pests and diseases by quickly and efficiently clearing out any problem parts of the combs.
And it may well have worked, but any prospective results were soon eclipsed when 26 of the test colonies were accidentally released from strict quarantine in 1957 and they escaped. They quickly interbred with the local honeybees and a new much more aggressive bee strain resulted.
How deadly is the Africanised bee?
Its sting was no worse than ‘ordinary’ honeybees, but it more vigorously and persistently attacked anyone who came near, often pursuing them many hundreds of metres from the colony, and stinging in far greater numbers, resulting in badly injured victims and even some deaths. The epithet ‘killer’ became a tabloid trope, and panic ensued.
During the 1970s they spread through the Amazon basin by interbreeding with local honeybees. In 1982 they were in Central America, and had reached Mexico and the southern USA by 1985. They continued to spread and currently occur in about the southern half of the USA. Because they are more ‘wild’ and less domesticated that the standard European stocks, they swarm more often and abscond from the beekeeper hives to establish feral colonies. Removal of these has become a mainstay of US pest control companies, previously more used to getting rid of unwanted wasp nests from people’s porches.
What do Africanised bees look like?
Africanised bees look no different from the other honeybees. Any minor differences in body size and wing length are only apparent when large numbers of specimens are collected, measured and statistically compared. It is really only their behaviour which identifies them.
Where do Africanised bees live?
They are more likely to swarm, and the swarm is more likely to travel further away from the nest it budded from. They are more likely to nest in ground hollows, rather than hollow trees. They have a larger ‘alarm radius’ around the nest, and a higher proportion of guard bees to do the defending once the alarm is raised.
They have become the dominant bee in South American hives, and many beekeepers rate their honey production higher than the traditional bees they have replaced. They are better at resisting pests and diseases, including Varroa mites and the mysterious colony collapse disorder.
Could they come to Britain?
But they are unlikely to get to northern Europe. They excel in tropical climates, but are evolutionarily unused to coping with harsh winters, and cannot survive long periods of nectar deprivation. The Asian hornet got to Europe in the form of fertilized queens packed in crates from China. Thats the way social wasps do these things. Each wasp colony is started fresh, from scratch, each spring, a single queen working on her own until her first cohort of worker daughters emerge to start helping her.
But honeybees travel in swarms — a queen and many thousands of workers, budding off from the old nest to fly off en masse to found a new colony elsewhere. They may be able to travel and expand their geographic range under their own steam. But it is highly unlikely that a colony could get accidentally packed up in a shipping container and survive enough to cross the Atlantic Ocean. And they haven’t yet managed to cross the Sahara from their original homeland either.
So, do Africanised honeybees deserve their ‘killer’ name. Estimates suggest there are still about 2 or 3 deaths a year. Worldwide there are probably a similar number of deaths from ‘normal’ honeybees. I’d say no, they don’t deserve that tag. Not really. But, like all honeybees, they should still be treated with respect.
