Social insects line up to die for the sake of their colony; however, few do it with as much gory gusto as soldiers of the termite, Globitermes sulphureus. The nests of this Southeast Asian termite are often plundered by ants. The soldier termites use their mean-looking mandibles to prevent the marauders from entering the nest, but sooner or later some ants may get in amongst the termites and more desperate defences are called for.
Fortunately for the termite colony, the altruism of the soldiers knows no bounds. Occupying some of the soldier termite’s thorax and much of its abdomen is a large frontal gland containing a yellowish gunk. The walls of this gland are very thin and when the termite has repelled the invaders as much as it can with its mandibles it uses it mandibular muscles to burst itself letting the goo from the frontal gland ooze out. This gloop becomes very tacky on contact with the air and the attacking ants get hopelessly entangled.
Needless to say, the split in the soldier termite’s little body is severe and fatal, but in throwing a seven and taking an ant or two with them they have helped save the colony. This is surely the zenith of altruistic behaviour.
Prestwich, G. D. Defense mechanisms in termites. Annual Review of Entomology 29, (1984)
Deligne, J., Quennedey, A. & Blum, M. S. “The enemies and defense mechanisms of termites”. In Hermann, H. R. (ed.) Social Insects Vol. II, New York, Academic Press, 1982, pp. 1-76201-232.
Bordereau, C., Robert, A., van Tuyen, V., and Peppuy, A. Suicidal defensive behavior by frontal gland dehiscence in Globitermes sulphureus Haviland soldiers (Isoptera). Insectes Sociaux 44, (1997) 289-297.
Scheffrahn, R. H., Kreck, J., Su, N. Y., Roisen, Y., Chase, J. A., and Mangold, J. R. Extreme Mandible alteration and cephalic phragmosis in a drywood termite soldier (Isoptera: Kalotermitidae: Cryptotermes) from Jamaica. Florida Entomologist 81, (1998) 238-240.