Mitochondrial gene sequence questions Reticulitermes sp social structure (Isoptera : Rhinotermitidae)

Termites are unique among the social insects. Isoptera is the only Order wi thin the Insecta comprised entirely of diploid animals whose polyethic, cas te-filled societies contain both male and female workers. The cryptic lifes tyle, complex caste system, dynamic developmental pathways, and social comp osition present significant challenges to scientists attempting to delineat e the development of and interactions within subterranean termite societies . For example, it is assumed that subterranean termite populations from the economically important genus Reticulitermes are closed and established by a single queen and a single king. As the colony grows progeny of the royal progenitors, secondary reproductives, develop that mate with their nest-mat es to produce progeny (1, p. 138), This view of subterranean termite social structure has been the foundation for discussion and research on topics as diverse as eusocial evolution and control tactics based on population mana gement. Although secondary reproductives may be numerous in Reticulitermes populations, female secondary reproductives are direct descendants of the q ueen and, as such, both inherit and pass on her mtDNA legacy. Thus each col ony should present the mtDNA fingerprint of the founding queen. Here we pre sent maternally inherited mitochondrial DNA (mtDNA) sequence from randomly chosen individual termites collected over three years from a single inspect ion port (feeding site). Phylogenetic analyses of cytochrome oxidase II (CO II) sequence demonstrated unique mtDNA genotypes among dates and within a s pecific date. These unexpected results are the first mtDNA data to challeng e the accepted assumption of a closed Reticulitermes colony with a single m atriarch.