COMPARATIVE MORPHOLOGICAL STUDY OF BRISTLES ON CATERPILLARS WITH MEDICAL RELEVANCE IN MISIONES

MILENA GISELA CASAFÚS; MATÍAS NICOLÁS SÁNCHEZ; ADRIANA INÉS ZAPATA; MARÍA MERCEDES MARTÍNEZ; DANNY ANDREA SOTO; ANA TEREZA BITTENCOURT GUIMARÃES; MARÍA ELISA PEICHOTO

Buenos Aires

Congreso; Reunión Conjunta de Sociedades de Biociencias; 2017

Sociedades de Biociencias

Caterpillars (larval stage of butterflies and moths) have urticating bristles which protect them from predators and are also responsible for the cutaneous reactions observed when human beings inadvertently lean against them. In recent years, accidents caused by different species of caterpillars have become more common among people living in Misiones. Taking into account that the biology of these animals remains to be poorly understood, we conducted a morphological study of the urticating bristles in representatives of the two families that are most frequently involved in accidents in this province: Saturniidae (Automeris naranja, Hylesia nigricans, Leucanella memusae, Lonomia obliqua) and Megalopygidae (Megalopyge lanata, Podalia orsilochus and Podalia aff. fuscescens). The external morphology of the caterpillars (scoli and spines) was observed and photographed under a stereomicroscope. The median dorsal region of caterpillar bodies were dissected and isolated, cleaned, critical-point dried, coated with a thin layer of gold, and finally examined by scanning electron microscopy. In this study, all caterpillars exhibited scoli with spines that bear a hollow canal. In L. obliqua, we could observe some spines that possessed a circular groove similar to a ring-like structure, and other spines that lacked this groove. The latter were the only type of spines that we could observe in A. naranja, H. nigrincans and L. memusae. The scoli of P. orsilochus, P. aff. fuscescens and M. lanata exhibited similar structures, showing long hairs with transverse striations and spicules, and short and hollow spines. It is noticeable that the saturnid H. nigricans also exhibited long hairs with spicules. Altogether, this is the first comparative morphological study showing the way in which different species of Argentinian caterpillars can induce an irritant or toxic dermatitis in humans.