Most venomous caterpillar

- Who
- giant silkworm moths, genus Lonomia
- Where
- Brazil
- When
- 18 November 2014
The most venomous caterpillars are those of the giant silkworm moths belonging to the genus Lonomia, native to Brazil and elsewhere in South America. These caterpillars, referred to as assassin caterpillars, are very well camouflaged when resting on the bark of trees, so are not readily perceived. However, the LD50 for their venom, a potent anticoagulant contained in their bodies' dense covering of hairs, is 0.19, and if a person should inadvertently touch a group of these hairy cryptic larvae present on a tree trunk or branch, this can cause massive internal haemorrhaging, renal failure, haemolysis and even death (most frequently resulting from intra-cranial haemorrhaging).
Due to its anti-coagulant effects, the venom of Lonomia caterpillars has been – and continues to be – the subject of considerable scientific research relating to the possibility of extracting some medically beneficial substances from it.