Incompatibility and host plant differences among populations of Tetranychus kanzawai Kishida (Acari: Tetranychidae)

Abstract

Reproductive incompatibility is known to occur in Tetranychus kanzawai. K strain females were found to be incompatible with T strain males, i.e., a cross between K strain females and T strain males resulted in only male progeny, whereas the reciprocal cross resulted in a higher egg hatchability but in a reduced sex ratio. To determine whether T. kanzawai populations collected from different localities belonged to either the T strain or the K strain, 74 local populations were tested. Of these populations, eleven belonged to the K strain and the others belonged to the T strain. Wolbachia infection occurred in local populations belonging to both the T and K strains. As all of the infected populations harbored a Wolbachia strain which does not influence compatibility of the host, Wolbachia is not responsible for the incompatibility between the T and K strains. Host plant specificity varied among local populations. Some populations successfully matured on tea, some attained maturity on hydrangea, and some were unable to develop on either tea or hydrangea. Thus, a wide range of genetic divergence was observed in T. kanzawai.