Giant swallowtail butterfly larva displaying its giant osmeterium

Giant swallowtail butterfly larva displaying its giant osmeterium
Originally uploaded by HugoBR.

Sao Luis, Maranhao, Northeast of Brazil. About 5 cm of size. I found it in a orange tree. Look that it owns retractible horns in form of swallow-tail. This organ is an eversible glandular sac on the first thoracic segment that secretes an unpleasant-smelling substance, providing both an olfactory and visual shock for would-be predators.

Tentando obter uma supermacro, acabei registrando um comportamento surpreendente da lagarta da laranjeira. Ao tocar acidentalmente sua cabeça, ela expeliu dois chifres surreais que, além de serem visualmente agressivos, exalavam um forte odor almiscarado, numa estratégia de defesa evolutivamente moldada para afastar possíveis predadores.

While trying to get a supermacro, I finished registering this surprising behavior of the orange tree caterpillar. When I touched accidentally its head, it expelled two surreal horns that, beyond being visually aggressive, exhaled a strong musk odour, in a strategy of defense evolutionarily molded to move away possible predator