Is only the first mating effective for females in the Kanzawa spider mite, Tetranychus kanzawai (Acari: Tetranychidae)?

Although only the first mating is effective for females in Tetranychus urticae (Acari: Tetranychidae), it remains unclear whether this is also true for closely related species, such as T. kanzawai. To address this question, I analyzed paternity in the progeny of T. kanzawai females that had been observed to copulate with two males by using a microsatellite DNA marker. In this study, mating was allowed to take place without experimental interruption. The results show that progenies were sired by both males in only 1 of 14 families, whereas progeny were sired only by the first males in the other families. This result suggests that only the first mating would be, by and large, effective in T. kanzawai.