Over half a century ago, a perfectly innocent experiment ended up creating super-aggressive extra-stingy “killer bees”. Now scientists have worked out how to turn normal bees into these nasty creatures just by tweaking their brain chemistry. Because more killer bees are just what we wanted.
Back in the 1950s, a Brazilian entomologist was trying to create honey bees that were well-adapted to a tropical climate and could produce more delicious honey than regular bees. He crossbred various species of European honey bee with the African honey bee (Apis mellifera scutellata). But something unexpected happened. The resulting bees were incredibly aggressive creatures, now referred to as Africanized honey bees or, more commonly, killer bees.
The newly bred bees were kept in quarantine. But in 1957, they escaped, and 26 swarms buzzed their way to freedom. Unfortunately for us, these killer bees spread through the Americas, making their way to the US in 1985.
The bees are actually smaller than their European counterparts, and the venom in their stings is no deadlier. Rather, it’s the insects’ fiery tempers that turn them into “killers” – they will chase you for a quarter of a mile (400 meters) and sting you 10 times more than your average bee. Ouch. And if you’re allergic to their stings, it’s not good news. Killer bees have killed about 1,000 people, as well as other animals like horses.
But why are they so aggressive? Well, researchers from the University of Sao Paulo State in Brazil set out to investigate, publishing their findings in the Journal of Proteome Research. To collect some bees without getting attacked, they dangled balls of leather near killer bee hives. Assuming they were being ambushed, the bees angrily swarmed the balls and began stinging. The researchers then picked the bees out of the leather and froze them in liquid nitrogen.
The researchers took a look at the insects’ brain proteins (neuropeptides) using a technique known as mass spectral imaging. They spotted differences between the lengths of two groups of these neuropeptides.
The first, Allatostatins A, are involved in bee learning, memory, and general development. The second – tachykinin-related peptides – are a bit more mysterious but thought to be related to the processing of sensory stimuli. The researchers found that angry bees had shorter versions of these proteins than other honey bees. They were also located in slightly different brain clusters (neuropils).
Then, the scientists decided to see whether they could turn chill bees into killers. They anesthetized some relaxed bees and injected them with shortened versions of the two proteins. The bees were furious when they woke up, thanks to their new brain features. It's still unclear why shorter versions of these proteins have such an impact on behavior, so we’ll need some more research to find out.
[H/T: Science Alert]