Defense Mechanisms of Termites

Abstract

For predators of all sizes, termite colonies are dangerous but well-stocked pantries. The success of termites over the last 150 million years is due in large part to the development of elaborate architectural, behavioral, morphological, and chemical strategies for colony defense. Indeed, the literature on termite defense mechanisms has grown from a handful of chemical and observational studies to several hundred references in the last fifteen years. Among these are comprehensive reviews on chemical defenses of termite soldiers (70, 71, 74, 75), defense mechanisms and enemies of termites (25, 40), morphology and ultrastructure of termite defense glands (98), and the chemical systematics of termite exocrine secretions (76). In addition, isopteran defenses are portrayed in relation to those of other arthropods in an excellent monograph by Blum (10) and in a recent review by Pasteels et al (66). This review focuses on mechanical and chemical defense mechanisms of individual termites. The text presents the mechanical and chemical defense modes of workers and soldier termites in an analytical fashion. To complement this presentation, a comprehensive table is provided in which known defense strategies, chemicals, and habitats are arranged phylogenetic ally for all ter­ mites for which literature citations were available through March 1983. This table is designed to facilitate the location of relevant literature on the defensive mechanisms and ecology of any given taxon, and it fills a conspicuous void in the review literature to date. The importance of predators (14, 25, l00a), mound morphology, and behavioral ecology (19, 20, 57) in understanding how defenses are successful in an evolutionary ecological sense are not stressed. The bias of this review is chemical, and the author regrets omissions or