Normal bees and killer bees

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Africanized bees, commonly known as "killer bees", are much more aggressive than their European counterparts. Now, a team of researchers have examined the changes in neuropeptides that take place in the brains of these bees during their aggressive behavior and have shown that they can turn normal bees into 'killer' by injecting certain peptides.

Only a few neuropeptides make the difference between a honey bee and another that has an irritable need to wipe out everything that moves.

To discover what it is that makes Africanized "killer bees" so hostile, the State scientists at the University of São Paulo (Brazil) compared their neurochemistry with that of their more docile relatives and found that it is mostly due to a surprisingly simple chemical change.

The reputation of killer bees is well deserved. Its venom is no more lethal than average honey bees and they are even a little smaller, but they are incredibly aggressive, and it does not take much provocation to incite a swarm of these bees to become a furious and poignant pain machine.

The more hostile an animal is, the more caution you have to have

These bad-tempered striped insects appeared in the late 1950s, after Brazilian beekeepers imported an African variety of Apis mellifera scutellata in order to increase honey production. It seems that the bees did not understand the fine print very well and ended up paying for the honey bees.

Since then, these aggressive hybrids have spread to northern California and remain a legitimate threat. Several hundred people have lost their lives due to their implacable twinge. And is that this subspecies is also extremely sensitive to the presence of humans. They usually attack the eyes and the face, and the only thing that can be done before them is to run away.

But what happens in your brain to act in this way?

To get to the bottom of the mystery, the researchers of this last study had to collect a sample of killer bees (something not without danger). Using a rather curious trick they managed to catch them to observe their tiny brains.

The comparison of the full range of brain proteins from two bee samples using mass spectral imaging revealed a clear, but simple difference.

One of the suspected proteins was called Apis mellifera Allatostatins A, a neuroprotein that is already known to play a key role in the learning and memory of bees, as well as in their overall development.

The other group of proteins, described as tachykinin-related peptides, seems to influence sensory processing.

In aggressive hybrids, these two groups of neuropeptides had been cut into shorter proteins, and found in different groups of brain tissue called neuropiles.

To verify that these proteins were significant in the transformation of the behavior of the bee, the scientists injected in the brain of a group of non-aggressive bees truncated forms of these neuropeptides.

As expected, the bees did not seem very happy when they woke up, because having modified their brain chemistry they had also become killer bees.

However, it is still unknown why the size and distribution of these neuropeptides lead to such aggressive behavior. Learning more about the cascade of effects that these proteins have on the nervous system of a bee could tell us more about the development of the nervous systems of bees, as well as those of insects in general.