“Beware Predators, We're Poisonous!”
by Guin Zambatis
This is the time of year when little black moths which look like wasps are seen in swarms flying in front of cars and visiting the flowers of many shrubs such the Velvet Wild-medlar (Vangueria infausta) and Buffalo-thorn (Ziziphus mucronata). These are the Burnet moths.
Many people associate moth activity with night time but a few species such as Burnet moths, are active during the day. Burnet moths are poisonous because their bodies contain cyanide throughout their lifecycle. The vivid coloration serves as a warning to ‘would be’ predators that they are distasteful. This anti-predator phenomenon is known as aposematic coloration. According to some sources these moths produce their own toxins and do not, like many other insects, obtain their toxins from the food that they eat. The larva of the subfamily Zygaenidae, to which these moths belong, are said to have cavities in which they store the cyanide this they excrete as defense droplets when molested (Niehuis et al., 2006).
The Burnet moths are often confused with the Handmaiden moths which are from the family Cteuchidae. These moths though, are not toxic and possibly mimic the poisonous burnet moths as they are also active during the day.
There are approximately 100 species of burnet moths in southern Africa. The species in the illustration is the Gold Spotted Burnet (Arniocera auiguttata), belonging to the family Zygaenidae and subfamily Pompostolinae. In the Lowveld these moths are usually seen during the months October and November.