POPULATION GENETIC-STRUCTURE OF THE NEOTROPICAL TERMITE NASUTITERMES NIGRICEPS (ISOPTERA, TERMITIDAE)

Monogamy and inbreeding are often thought to characterize the breeding system of termite societies. However, few studies have employed genet ic markers to ascertain either the genetic structure of single colonie s or the extent of local inbreeding. This study employs allozyme analy sis to investigate the breeding system of Nasutitermes nigriceps with respect to the number of reproductives contributing to single colonies , and the level of inbreeding within and among local colonies. The maj ority of the 136 nests examined from three study fires showed patterns of protein polymorphism consistent with their origin from a single ma ted pair, establishing that monogamy is indeed the predominant mode of reproduction. A small proportion of colonies (N = 7) had genotypic fr equencies suggesting that offspring were not all full-siblings. The ge neric composition of all colonies appeared stable through a one-year i nterval, suggesting that the observed genetic attributes represent rel atively persistent reproductive associations. Wright's (1978) F-statis tics showed moderate differentiation among study sites, indicative of restricted gene flow and the occurrence of inbreeding at a regional sc ale. However, mating appeared to be random at single sites as the infe rred genotypic frequencies of colony progenitors did not deviate from Hardy-Weinberg expectations, indicating little inbreeding in the study populations.