Observations on little known poison hairs of some lepidopterous larvae

Abstract

Even for the past few decades, many cases of disagreeable dermatitis caused by contact with hairy caterpillars have been reported from various parts of this country. These insects are taxonomically well known and their life histories were also made known. However, besides nettling hairs of certain species, only little information is available in regard to the structure and sting mechanism of the larval poison hairs. Being enabled to collect a number of materials, it has recently been confirmed that some caterpillars belonging to Zygaenidae, Arctiidae and Lymantriidae also possess poison hairs of characteristic shape and function, quite similar to those of Artona funeralis Butler, which was reported in my previous paper. This paper deals with the morphology of these poison hairs, together with the dermatitis experimentally caused by them. My sincere thanks are due to Dr. Syoziro Asahina, Chief of the Department of Medical Entomology, National Institute of Health, Tokyo, for his valuable advices and kind criticism given during the course of this study. I am also deeply indebted to Mr. Ryonosuke Koyama, Forest Protection Division, Government Forest Experiment Station, Ministry of Agriculture and Forestry, and Dr. Kazuo Saitoh, Biological Institute, Faculty of Literature and Science, Hirosaki University, for the gift of the specimens of Illiberis psychina, Illiberis pruni and Lymantria dispar.