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Science 1 January 1982:
Vol. 215. no. 4528, pp. 83 - 85
DOI: 10.1126/science.215.4528.83
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Articles

Spray Aiming in Bombardier Beetles: Jet Deflection by the Coanda Effect

THOMAS EISNER 1 and DANIEL J. ANESHANSLEY 2

1 Section of Neurobiology and Behavior, Division of Biological Sciences, Cornell University, Ithaca, New York 14853
2 School of Electrical Engineering and Section of Neurobiology and Behavior, Cornell University

Bombardier beetles of the carabid subfamily Paussinae have a pair of flanges, diagnostic for the group, that project outward from the sides of the body. Behind each flange is a gland opening, from which the beetles discharge a hot, quinone-containing secretion when disturbed. The flanges are curved and grooved and serve as launching guides for anteriorly aimed ejections of secretion. Jets of fluid, on emergence from the gland openings, follow the curvature of the flanges and are thereby bent sharply in their trajectory and directed forward. The phenomenon is illustrative of the Coanda effect, widely applicable in engineering and responsible for the familiar tendency of liquids to curve around spouts and down the front of containers when being poured.

Submitted on June 2, 1981


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Spray mechanism of the most primitive bombardier beetle (Metrius contractus).
T Eisner, D. Aneshansley, M Eisner, A. Attygalle, D. Alsop, and J Meinwald (2000)
J. Exp. Biol. 203, 1265-1275
   Abstract »    PDF »
Spray aiming in the bombardier beetle: Photographic evidence.
T. Eisner and D. J. Aneshansley (1999)
PNAS 96, 9705-9709
   Abstract »    Full Text »    PDF »
Defensive production of formic acid (80%) by a carabid beetle (Galerita lecontei).
C. Rossini, A. B. Attygalle, A. Gonzalez, S. R. Smedley, M. Eisner, J. Meinwald, and T. Eisner (1997)
PNAS 94, 6792-6797
   Abstract »    Full Text »    PDF »
Defensive spray of the bombardier beetle: a biological pulse jet.
J Dean, D. Aneshansley, H. Edgerton, and T Eisner (1990)
Science 248, 1219-1221
   Abstract »    PDF »


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