Abstract
In the course of exploratory field studies on arthropods with defensive glands, we came across two species which emit a strong and persistent phenolic odor when handled. One is a carabid beetle (Chlaenius cordicollis Kirby), the other a chordeumoid millipede [Abacion magnum (Loomis)]. The fact that both animals produce repellent secretions is not surprising, since many other carabids and millipedes are well known for their defensive glands. But the particular phenolic odor possessed by these two species is unIike the odor of any other arthropod secretion that has been studied (for a summary of defensive secretions of arthropods see Roth and Eisner, 1962).The purpose of this paper is to report on the nature of the two phenols involved, and to discuss the structure and mode of operation of the glands, as well as their defensive effectiveness. Both species were collected in the environs of Ithaca, N. Y. Abacion was from leaf litter in deciduous woods, and Chlaenius from beneath rocks near a creek bed. We had available for study ten specimens of Abaciorz and about two dozen Chlaenius.