March 2011. A butterfly in rubber plantations in the Cameroons. The caterpillars have hairs which cause irritations. An identification was requested as well as how the irritations can be prevented, and the pest controlled.
A reply from a member said the following: "a nice picture of a typical Mylothris chloris (see photo on www.learnaboutbutterflies.com).
This is a member of the pyridae. However, all the member that replied could not see this species being urticating. It feeds mostly on mistletoes, but also on Osyris (Santalaceae). The family that contains the itchy caterpillars is the lymantriidae - tussock moths.
Could it be that this pierid butterfly was common at the same time as the other species, or shortly after, the caterpillar that was causing problems. Are there any pictures of the caterpillars that caused the problems.
Later, another image was sent, this time a caterpillar. The image was not clear, but it was probably a member of the tussock moth family. Typicaly, members of this family have upstanding bunches of bristles rather like a toothbrush, but they should have a pair of longer tufts pointing forwards from each side of the head. Occasionally, members of this family appear in large numbers and they feed on a wide range of plants. The adults are nocturnal, and often missed. They cover their eggs with hairs from the body, and these too are irritating.
Later, December 2012, another emall was sent from the Cameroon. The workers are again reporting the itching caused by caterpillars and their pupae. Cocoons have been collected and adults reared. Contrary to what the workers believe, the Mylothris butterfly is not the adult of the urticating caterpillars. Our laboratory results have shown that it is a moth - photo attached.
There were two suggestions from members:
- A member thought that this moth was Trabala charon of the family Lasiocampidae (which often have urticating caterpillars). This species has been recorded in Cameroon, but the only information found suggests that the host includes Terminalia glaucescens, Terminalia mantaly and Combretum racemosum. See, http://www.afromoths.net/.
- Another member suggested Euproctis sp. (previously placed in Lymantriidae, but now in the subfamily Lymantriinae of the family Erebidae), rather than a Lasiocampidae, see e.g. http://www.africanmoths.com/pages/LYMANTRIIDAE/LYMANTRIIDAE/euproctis%20sp3.htm. This is a species-rich genus in Africa, and at least some are known to be urticating, both as caterpillars and from the hairs on the end of the female's abdomen, which are placed in a covering over the egg batches. A member came across an example in Somalia in 1986. Adults were attracted to the lights of the Juba Sugar cane processing factory; the female moths laid batches of hair-covered eggs on the structure, which the workers then got on their skin causing rashes and dermatitis. This is likely to be an outbreak pest normally kept under control by natural enemies. Each outbreak is likely to die down over time, but if an intervention is considered necessary, a Bt product for use on the young caterpillars is suggested.