Main image for Taxonomy and Systematics

Female and male strepsipterans. A free-flying male (bottom right) and an endoparasitic female whose cephalothorax (arrow) extrudes from the cuticle of the cricket host. The male is about 2mm in length and the cricket about 10mm.

Photograph by Jeyaraney Kathirithamby.

The diversity of species and the diversity of interactions between species, such as hosts and parasites are made up of a diverse and complex entangled bank and are linked through processes such as specialization and coevolution.

Understanding the diversity of life and the interactions between hosts and parasites is becoming more urgent now in the face of rapid ecological degradation. To address some of this complexity the entomophagous parasitoid Strepsiptera (Insecta) is being studied. The sexually dimorphic male and female Strepsiptera, especially in the family Myrmecolacidae, provide an opportunity to study speciation in the sexes that parasitize different disparate hosts (Hymenoptera and Orthoptera/Mantidea). With molecular data we have show that currently recognised morphological species in fact comprises a set of cryptic species. Phylogenetic structure within these cryptic complexes reflect host associations and glacial refuge phylogeography.

This research presents an unprecedented opportunity to combine both traditional and modern taxonomic methods to improve our understanding of host race formation and speciation and presents an excellent model study system in evolutionary ecology. Current and recently projects have been conducted in the southern States of USA, Mexico, Panama, Argentina, Brazil, Spain, Australia, Papua New Guinea, Japan, India, Philippines and South Africa.

Some papers of interest:

J. Kathirithamby (2009) Host- parasitoid associations in StrepsipteraAnnual Review of Entomology, 54: 227-249.

D. P. McMahon, A. Hayward & J. Kathirithamby (2009) Mitochondrial genome of Mengenilla australiensis(Strepsiptera). BMC Genomics, 10: 603.

J. Kathirithamby, A. Hayward, D. McMahon, R. Andreazze, H. Tadeu de Almeida Andrade, R. S. Ferreira & D. Fresneau (2010) Conspecifics of a sexually dimorphic, heterotrophic heteronomous species of Strepsiptera (Insecta) are matched by molecular characterizationSystematic Entomology, 35: 234-242.

A. Hayward, D. P. McMahon & J. Kathirithamby (2011) Cryptic diversity and female host specificity in a parasitoid where the sexes utilize hosts from separate ordersMolecular Ecology, 20: 1508-1528.

D. P. McMahon, A. Hayward & J. Kathirithamby (2011) StrepsipteraCurrent Biology, 21: K271-272.

D. P. McMahon, A, Hayward &, J. Kathirithamby (2011) The first molecular phylogeny of Strepsiptera (Insecta) reveals an early burst of molecular evolution correlated with the transition to endoparasitismPLoS ONE, 6 (6): e21206, 10pp