Genetic Structure of Termite Colonies and Populations

Abstract

Increasingly, researchers are using molecular markers to investigate the genetic structure of termite colonies and populations. The studies are providing insights into the natural history and evolution of Isoptera in unprecedented detail. At the level of the colony, genetic studies reveal the breeding structure and degrees of inbreeding. In many species colonies are often headed by monogamous pairs of reproductives, although there is considerable variation in breeding structure within and between species in the proportions of colonies with multiple functional reproductives, usually containing inbreeding neotenics. Recent studies have identified negative consequences of inbreeding with important consequences for colony breeding structure. Genetic evidence does not support budding as a common mode of reproduction in termites. In most cases studied to date, alates appear to disperse far enough to promote extensive gene flow among populations within about 10 km, while populations at 50–100 km often show moderate to strong genetic differentiation. There has also been considerable progress in phylogeographic studies, relating differentiation among populations and speciation of termites to geological events. The few studies to date of invasive termite species suggest that some successful invaders (e.g. Reticulitermes flavipes) may undergo changes in breeding structure in the introduced range toward larger, unicolonial societies, whereas other introduced populations (e.g. Coptotermes formosanus) do not exhibit unicolonial characteristics. The powerful approach to termite colony and population genetics afforded by molecular markers will address a wide range of issues of fundamental importance to termite biology and evolution. With continued advancement in the tools for characterizing genetic variation, we anticipate rapid progress in termite colony and population genetics.