Subject: big crowd of caterpillars.
Location: Phuket, southern Thailand
May 16, 2015 4:08 am
Found these motionless near the foot of a tree. About 100 of them. they are about 2 inches/5 cm long and were all facing in the same direction. Though they were well camouflaged, a big pile if droppings below was a bit of a giveaway.
We found what appears to be a good visual match to your caterpillars on Shutterstock, but alas, it is only identified as a “blue spotted caterpillar”. We believe your images depict an aggregation of Lappet Moth Caterpillars from the family Lasiocampidae, but we have not had any luck with a conclusive identification. Several similar looking caterpillars identified only as Lasiocampidae are pictured on Thai Bugs.
Update from Alasdair
Thai friends have identified it. Eupterote tertacea (Walker). Not much on the web and all of it in Thai. It’s a well known pest here – moves in gangs, infests and destroys sugar cane. When touched can cause severe itching.
Thanks for that information Alasdair. We found a few listings in Thai with that spelling, including this Thai site, but there are more hits with the spelling Eupterote testacea. We do not believe that is the correct identification. We found images of the Caterpillar of Eupterote testacea on Insects of Thailand and they look nothing like those in your images, and images on Stock Photo appear to be an even different species. An image on Guzjung Story does resemble your caterpillars. Since we cannot really locate a reputable site with images, we are still classifying this as unidentified.
Thanks for trying. Really impressed by the work you chaps are doing.