Spray aiming in the bombardier beetle: Photographic evidence

Spray aiming in the bombardier beetle: Photographic evidence

^*Section of Neurobiology and Behavior and ^‡Department of Agricultural and Biological Engineering, Cornell University, Ithaca, NY 14853

Contributed by Thomas Eisner

Abstract

Bombardier beetles, when physically assaulted, eject a hot quinonoid spray from the tip of the abdomen. Photographic evidence is presented demonstrating that the African bombardier beetle, Stenaptinus insignis, can aim its spray in virtually any direction. It can target its individual legs, and even the individual segments of its legs. Moreover, in aiming at a leg, it takes into account the postural orientation of that leg. The beetle is able even to target sites on its back. It is postulated that the ability to aim helps the beetle mainly in defense against ants.

Footnotes

↵ † To whom reprint requests should be addressed at: Section of Neurobiology and Behavior, W347 Mudd Hall, Cornell University, Ithaca, NY 14853. E-mail: te14{at}cornell.edu.
↵ § This paper is no. 162 in the series “Defense Mechanisms in Arthropods.” Paper no. 161 is ref. 25.