Pests > Pests Entities > Insects > Moths & butterflies > Euproctis > Hairy caterpillars, swarming, Indonesia

April 2011. Accounts of hairy caterpillars have been broadcast from Omndonesia. A member from Australia asked what they could be. See:

news.blogs.cnn.com/2011/04/13/hairy-caterpillars-swarm-over-parts-of-indonesia/

and

www.sott.net/articles/show/227372-Caterpillars-Swarm-Indonesia-s-Bali

A member wrote: According to Dr. Aunu Rauf, Bogor Agricultural University, it is Arctornis submarginatus (Walker) (Lepidoptera: Lymantriidae). They are larvae of tussock moths. They swarm and enter houses. Prolonged drought is often the cause of the upsurge in populations.

Another member said they were a species of Euproctis, possibly E. fraterna (Lepidoptea:Lymantriidae). The adults are yellow-golden, about 1.5-2 cm in length. He had worked on E. fraterna in the Maldives in 2004 shortly after an outbreak of the caterpillar had subsided. Large ‘armies’ of the caterpillars invaded houses and forced people out as their hairs were highly irritating. In several cases, people were hospitalised with serious breathing problems. Skin irritations occurs from allergic reactions.

The outbreaks typically follow prolonged drought (as mentioned for Indonesia), which reduced populations of natural enemyies. The outbreaks lasted for 1-2 months, after which the moths were brought under control by their natural enemies.

Several natural enemies of the eggs and larval stages were found in the Maldives, and it’s very likely that there are many more in Asia. For instance, the literature from India, where E. fraterna appears to be common, refers to the pest with the common English name of ???Plum Hairy Caterpillar??? (Batra and Sinha (1971); Sandhu et al. (1977); Butani (1978) and ???Hairy Caterpillar??? (Oblisami et al. (1969). These common names, however, do not appear to be widely used in other Asian countries where the species is present.

Results from literature searches showed that there are several other species of Euproctis, most of which appear to be found in Asia: E. flexuosa Veen from Java and the Dutch West Indies (Indonesia); E. lunata Walk. from India; E. pseudoconspersa from China, Taiwan, and Japan; and E. scintillans, which has been renamed Porthesia sp.; E. chrysorrhoea, the Brown tailed moth, is recorded from the UK (D. Palmer, pers. comm., 2004), where it also causes skin irritation to those who come in contact with the larvae (Anon, 2004).