Raiding honeybee colonies and sucking honey directly from the comb may seem suicidal for such a large moth. But adult death’s-head hawkmoths have numerous adaptations to help them survive:
Adult death’s-head hawkmoths are famous for making loud, high-pitched noises.
The moths squeak loudly when disturbed, but also when inside honeybee colonies.
Some scientists consider these squeaks similar to the piping sounds produced by queen honeybees, which make the worker bees stop moving around (the freezing response).
However, others dispute this as no-one has seen worker bees freeze in the presence of moths (Moritz et al 1991).
Acherontia atropos epipharynx - this small flap at the base of the proboscis enables the moth to 'squeak'.
The squeak is produced by a small internal flap at the base of the proboscis called the epipharynx. The noise is made up of 2 parts:
This process is repeated 40 to 50 times to produce the whole squeak.
Guard bees often attack death’s-head moths as they try and enter the hive (Moritz et al, 1991) but once inside, the defending workers rarely attack.
Some scientists suggest the skull mark on the moth looks rather like the face of a worker bee (Rothschild, 1985). But the moths raid at night, and it’s dark inside the hive anyway.
Acherontia atropos markings may resemble a worker bee's face
Others (Moritz et al, 1991) have compared the odours emitted by honeybees and death’s-head hawkmoths. They extracted the surface hydrocarbons from both honeybees and Acherontia atropos adults and compared them using gas chromatography.
The honeybee extracts consisted of 4 compounds:
The moth extracts were more complex, with many more compounds in the mix, but all 4 honeybee fatty acids were present. So, the death’s-head hawkmoths seem to be chemically 'invisible' to bees.
Honeybees are acutely sensitive to odours and can even distinguish between nest mates and non-nest mates. So, why are they fooled by such apparently gross chemical camouflage?
The answer may lie in their squeaking. But the moths use the same structures for squeaking and eating.
Scientists have found that after drinking honey, the moths can only make clicking sounds and are unable to squeak again for 5 hours (Newman, 1965).
So, if the squeak does pacify the bees, the moths must escape the hive quickly before the bees realise something is wrong and attack.