The British ‘death moth’
New research has found a species of moth, found in the UK, uses Cyanide to warn off predators. The Six-Spot Burnet Moth is covered in in red spots to warn off predators and can be found across the UK including Cornwall. This moth is unlikely to attack humans and even if it did it’s unlikely to cause any ill effect unless a large dose of their poison is ingested.
It has a natural variation in its wing markings and scientists wanted to see whether that gave an indication of how toxic an individual moth might be. While smaller and paler red forewing markings were associated with more cyanide in females, size and brightness of wing colour were no guide to cyanide levels in males.
Research Scientists at the University of Exeter used a model that can detect ultraviolet light to examine the moth, this showed a light which is invisible to human eyes but visible to many of the birds that prey on moths.
‘Many animals use aposematism (warning colouration) to tell predators it would be better to find lunch elsewhere,’ said study author Emmanuelle Briolat, of the University of Exeter. Such warning signals are generally ‘honest’ overall – meaning the markings genuinely indicate poison. ‘However, it’s less clear whether individuals within species vary in their markings according to how much poison they have. In the case of burnet moths, the weak correlations we found suggests the evolutionary pressures are more complex than simply driving colours to match toxicity levels.’
One of the main reason the Six-Spot Burnet Moth doesn’t advertise how toxic it is could be to do with the fact potential predators do not need any extra warning.