Comparative genetic study of the colony structure and colony spatial distribution between the higher termiteAmitermes parvulusand the lower, subterranean termiteReticulitermes flavipesin an urban environment

Abstract

In insects, ecological competition has often resulted in phenotypic changes and modifications to foraging areas. In termites - and social insects as a whole - colonies cannot easily escape competition through the relocation of their colony. In these species, the outcomes of inter and intra-specific competition are influenced by different life history traits, such as colony size, breeding system (number and types of reproductives), food preference, tunneling patterns, nest site selection, and antagonism between colonies. Here, we investigated variation in breeding system and spatial distribution among colonies of a higher termite Amitermes parvulus and a subterranean termite Reticulitermes flavipes within an urban landscape. We first developed microsatellite markers as a tool to study these life history traits in A. parvulus. Second, we assessed competitive exclusion or tolerance of A. parvulus and R. flavipes colonies by determining their fine-scale distribution using monitoring stations on a grid site, and their large-scale distribution across an urban landscape. Third, we investigated the breeding system of A. parvulus colonies. We showed that the numerous colonies of R. flavipes inhabiting a restricted area contrast with the few, but spatially expansive colonies of A. parvulus, suggesting these species face different degrees of intra-specific competition. We showed that colonies of A. parvulus frequently merged together, and all of them were headed by inbred neotenic reproductives, two characteristics rarely observed in higher termites. Overall, our study revealed drastic differences in colony structure, breeding systems and foraging ranges between the two species. These differences may reflect differences in food preference and food availability between the two species allowing their co-existence within the same urban environment.