Friday Cat-erpillar Blogging: Urticating Setae

Setae

Micrograph of Processionary Caterpillar Setae
Note the barbs at the distal ends
The sockets (holes) in the cuticle are left when hairs are dislodged

Processionary caterpillars of the genus Thaumetopoea produce urticating hairs. These hairs contain protein that can cause allergic reactions. They are defensive in nature like most caterpillar hairs. However, the hairs of Thaumetopoea can detach from the caterpillar and be dispersed by wind and deposited in the environment. The urticating hairs rest in sockets in the caterpillar cuticle and are easily dislodged. The distal ends of the hairs may have barbs. The barbs anchor the hairs in the skin and prolong contact.

In areas with outbreaks, allergic reactions can be triggered by contact with dispersed hairs alone and do not require the caterpillar. The largest problem areas are around the Mediterranean. The processionary caterpillars have been studied by European entomologists because of their interesting social behivor of walking in lines, head to tail.

About jjneal

Jonathan Neal is an Associate Professor of Entomology at Purdue University and author of the textbook, Living With Insects (2010). This blog is a forum to communicate about the intersection of insects with people and policy. This is a personal blog. The opinions and materials posted here are those of the author and are in no way connected with those of my employer.
This entry was posted in behavior, by jjneal, Caterpillar Blogging, Health. Bookmark the permalink.

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