EUROPEAN JOURNAL OF ENTOMOLOGY

Eur. J. Entomol. 94 (3): 335-348, 1997

Gonadotrophic and morphogenetic effects of a juvenile hormone analog treatment and ovary presence on last instar male and female Diploptera punctata (Blattaria: Blaberidae)

STOLTZMAN C.A., STAY B.

N/A

Application of the juvenile hormone analog, 7S-hydroprene, to last instar female larvae of the viviparous cockroach Diploptera punctata on day 1 resulted in vitellogenesis in the basal oocytes of the larval ovary, a peak of juvenile hormone synthesis not seen in controls, as well as maintenance of juvenile characteristics in the instar following the molt. To investigate whether juvenile hormone analog and/or the developing ovary was responsible for such changes in juvenile hormone synthesis, the present study used 7S-hydroprene treatment on intact and ovariectomized last instar females and on last instar males with or without an adult or last instar larval ovary. In last instar males, 400 µg of this JH analog was found to promote vitellogenin synthesis by the male fat body and its uptake by an implanted adult ovary for up to 10 days following treatment.
The metamorphic outcome following these treatments shows that hydroprene treatment in the presence of a larval ovary in females and an adult ovary in males resulted in a greater number of supernumerary larval molts than hydroprene treatment alone. This indicates that the ovary did contribute to higher juvenile hormone titers. However, hydroprene treatment did not result in a peak of juvenile hormone synthesis in females or males either with or without ovaries. Hydroprene treatment did result in vitellogenin in hemolymph and uptake in the ovary when a rapidly growing ovary was present.

Keywords: Juvenile hormone synthesis, vitellogenin, hydroprene, larval ovary growth, cockroach larvae, Diploptera punctata

Accepted: January 8, 1997; Published: July 30, 1997  Show citation