PARTHENOGENESIS-INDUCING WOLBACHIA IN TRICHOGRAMMA-KAYKAI (HYMENOPTERA, TRICHOGRAMMATIDAE) ORIGINATES FROM A SINGLE INFECTION

To determine the degree of within-population diversity of a parthenoge nesis-inducing Wolbachia symbiont in the parasitic wasp Trichogramma k aykai Pinto, Platner & Stouthamer, we established >200 isofemale lines of this (partly) parthenogenetic species from the Californian Mojave Desert. These were screened with Wolbachia-specific polymerase chain r eaction primers. An infection rate of 12.4% was found. We then generat ed 45 DNA sequences for the ftsZ gene and compared these with 19 seque nces from other Trichogramma species. We found a single nucleotide pos ition diagnostic for the T. kaykai symbiont. Phylogenetic analyses ind icated that this diagnostic position is a derived character and that a ll the Wolbachia symbionts in T. kaykai are very closely related; this suggests that all of them originate from a single, ancestral infectio n.