Biology of Subterranean Termites: Insights from Molecular Studies ofReticulitermesandCoptotermes

Abstract

Molecular genetic techniques have made contributions to studies on subterranean termites at all levels of biological organization. Most of this work has focused on Reticulitermes and Coptotermes, two ecologically and economically important genera. DNA sequence data have significantly improved our understanding of the systematics and taxonomy of these genera. Techniques of molecular biology have provided important new insights into the process of caste differentiation. Population genetic markers, primarily microsatellites, have furthered our understanding of the life history, population biology, community ecology, and invasion biology of subterranean termites. Recent results on the behavioral ecology of subterranean termites reveal a picture different from long-held views, especially those concerning colony breeding structures and foraging ranges. As additional molecular tools and genomic resources become available, and as more subterranean termite researchers incorporate molecular techniques into their approaches, we can expect accelerating advances in all aspects of the biology of this group.

Genetic diversity and colony breeding structure in native and introduced ranges of the Formosan subterranean termite, Coptotermes formosanus

“…During the process of budding genetically differentiated nests may still exchange workers (Husseneder et al 1998) which results in positive F IC -values (Thorne et al 1999;Bulmer et al 2001). Thus, budding may be a viable form of colony propagation in the Hawaiian islands; although this is rare in other C. formosanus populations (Vargo and Husseneder 2009). Propagation by budding, and the lack of successful colony foundation after swarming may explain the smallscale isolation by distance and the lack of admixture in the Maui populations.…”

“…As previously reviewed (Vargo and Husseneder 2009), F IC is the coefficient of inbreeding in individuals relative to their colony and reflects most clearly the colony's breeding system (Bulmer and Traniello 2002;Thorne et al 1999;Bulmer et al 2001). Empirical F IC values of colonies were compared among populations via independent samples t-test not assuming equal variances, and to values predicted by the computer simulations for different breeding systems (Bulmer et al 2001;Thorne et al 1999) by one-sample t-tests (SPSS 17.0).…”

“…For example, R. flavipes and R. urbis both have reduced genetic diversity and large extended family colonies with high numbers of neotenics in the introduced range of Western Europe (Dronnet et al 2005;Leniaud et al 2009Leniaud et al , 2010. In their native range in North America, R. flavipes colonies are mainly simple families (75%) or extended families (22%) with few reproductives (Vargo and Husseneder 2009).…”

“…Multiple reproductive strategies, including dispersal by swarming or budding (although not frequently observed), the high fecundity of queens, the ability to produce neotenics after death of the colony founders, etc. (Vargo and Husseneder 2009), might allow populations to adapt and compete in a wide range of environmental conditions. However, these characteristics are true for many termite species, while only a few are truly successful invaders.…”

“…Like some invasive ant species (e.g., Solenopsis invicta, Ross and Keller 1998), colonies of C. formosanus have two breeding structures: simple families headed by a single pair of reproductives (analogous to monogyne ant colonies) and extended families headed by numerous reproductives in analogy to polygynous colonies in ants, except that in termites the reproductives are inbreeding neotenics produced within the nest (reviewed in Vargo and Husseneder 2009). The large foraging areas of some Formosan subterranean termite colonies extend to over 1,600 m 2 Husseneder et al 2005), and may be comparable to supercolonies in ants.…”