Defenses of Nasutitermes Termites (Isoptera, Termitidae) Against Tamandua Anteaters (Edentata, Myrmecophagidae)

• DOI: 10.2307/2387872
• Publication Date: 2006-05-04T17:31:00Z
• Authors: Yael D. Lubin; G. Gene Montgomery
• Keywords: 0106 biological sciences; 01 natural sciences

When carton nests or covered trails of Nasutitermes termites were breached experimentally, nasute soldiers were recruited rapidly to the break, while workers retreated into the nest or trail. Nasutes mobilized both in larger numbers and more rapidly to breaks in nests than at sites away from the nest. Nasutitermes formed an important part of the diets of two species of Tamandua anteaters. Anteaters, however, ignored or actively rejected most nests of Nasutitermes that they encountered, and fed primarily at concentrations of Nasutitermes in logs, branches, and covered trails away from the nest. Feeding at carton nests occurred mainly when these nests contained winged reproductives and nymphs or ants living in association with the termites. Feeding on Nasutitermes was often accompanied by grooming behavior. A captive T. mexicana rejected recently killed nasute soldiers while accepting both workers and reproductives of the same species. We suggest that the nasute soldiers are an effective defense against predation by anteaters on the nest and speculate on the role of mammalian termite-eaters in maintaining the Nasutitermes defense system. AMONG THE MOST SPECIALIZED of termite defensive behaviors are the chemical defenses of the Nasutitermitinae (Termitidae). For a recent review of termite defense mechanisms, see Deligne et al. (in press). The nasute soldiers of Nasutitermes squirt a defensive secretion through the long, pointed rostrum (Ernst 1959). This sticky, strong-smelling secretion is produced in the cephalic gland which occupies almost the entire head capsule (Noirot 1969). Most nasute soldiers lack mandibles and appear to function solely in colony defense. The defensive secretions of several species have been analyzed chemically and contain the volatile terpenoid compounds a-pinene, ,3-pinene, limonene and others, as well as a high molecular weight non-volatile component (Moore 1964, 1969; Vrkoc et al. 1973; Prestwich 1975, 1977). The defensive behaviors of Nasutitermes and other Nasutitermitinae were first described at the turn of the century by Beaumont (1889-90) and Andrews (1911), and analyzed in the laboratory by Ernst (1959), Moore (1964), Nutting et at. (1974), Stuart (1969, 1975), and Eisner et al. (1976). The cephalic gland secretion is both an alarm or alerting pheromone (Ernst 1959, Moore 1969, Stuart 1975, Eisner et al. 1976) and a defensive substance which immobilizes or slows small arthropod predators such as ants, to which it may also be toxic (Ernst 1959, Nutting et at. 1974, Eisner et at. 1976). The influence of nasute defensive secretions on vertebrate predators has been largely a matter of speculation (e.g., Eisner et al. 1976; 121: "To what extent vertebrates might also be affected by these defenses remains to be