PCR-SSCP and sequence analysis of three Odontotermes spp. (order: isoptera; family: termitidae) on the basis of partial 16SrRNA gene

Compound eye formation in the termite Incisitermes minor (Isoptera: Kalotermitidae)

The postembryonic development and caste differentiation patterns of lower termites have been described multiple times in a variety of different species. However, most of these studies focused on gross ontogeny, without carefully describing the maturation of any particular organ or organ system. The few studies that have attempted to correlate caste development and organ differentiation have produced somewhat inconsistent results, especially in the area of eye formation. Therefore, in order to help further elucidate the relationship between eye formation and postembryonic differentiation in lower termites, we studied eye development in the termite, Incisitermes minor (Hagen). Eye formation in I. minor began in the earliest larvae, with only an eye primordium. However, in all later larval stages, characteristic eye structures were observed and were shown to progressively differentiate through larval and nymphal stages. Curiously, pigmentation began with three to eight groups of cells in early larvae and the number of these pigmented groups increased along the developmental time course. Ultimately, a uniformly pigmented eye area was formed by the early nymphal stage. The overall eye area also gradually increased along with normal caste development, but the characteristic lenses seen in a prototypical insect compound eye did not completely form until after the final nymphal stage. Electrophysiological measurements provided clear evidence that eyes were indeed functional at all stages of development where pigment was present. Based upon this data, the eye development pattern in I. minor appeared to follow a divergent pathway from holometabolous insects and an intermediate pathway between typical hemimetabolous eye development and the heterochronic shift observed in other termite species.

Diversity of Wolbachia in Odontotermes spp. (Termitidae) and Coptotermes heimi (Rhinotermitidae) using the multigene approach

The intracellular bacteria, Wolbachia, are well known for inducing reproductive alterations in arthropod hosts, especially insects. The ancient origin and huge diversity, combined with the ecological, biological and behavioral plasticity of termites, make the latter exciting candidates for studying the interactions of Wolbachia. In the present study, we investigated the distribution of Wolbachia in populations of Odontotermes spp. and Coptotermes heimi termites occurring in 14 colonies (12 Odontotermes spp. and two C. heimi) from different locations in India. A striking diversity was observed among Wolbachia strains in closely related hosts based on five MLST genes (ftsZ, coxA, fbpA, hcpA and gatB) and the 16S rRNA gene. Wolbachia variants from two supergroups (B and F) were found in both the termite genera under study. This is the first report of Wolbachia infection in the Odontotermes genus. Although F Wolbachia supergroup infection is already reported in Coptotermes lacteus and Coptotermes acinaciformis, in this study, the two C. heimi species exhibited infection by two distinctly different Wolbachia supergroups (B and F).