Abstract: As a juvenile hormone analog (JHA), pyriproxyfen has showed a very high efficacy in cockroach control. The effects of JHAs on vitellogenesis and reproduction in many insects have been widely reported. In this study, the effect of pyriproxyfen on the vitellogenesis and reproduction of Blattella germanica has been investigated by employing immunological and biochemical methods. When the female adults were treated with pyriproxyfen, the synthesis of vitellogenin in fat body was promoted, and the biomodel of vitellogenin in haemolymph exhibited a very different pattern, i.e. 2 peaks of vitellogenin content. Vt began to accumulate earlier and maintained at a very high level for several days, then decreased quickly afterward in the ovary of treated female. At the 9th day the Vt content lowered to half of the peak level in the normal adult of the same day-age. When the newly emerged female adults were treated with this JHA, they became sterilized.

Key words: pyriproxyfen, vitellogenin, vitellin, Blattella germanica, reproduction