Es. Ratna et al., LONG-TERM EFFECTS OF FENOXYCARB UPON REPRODUCTIVE ACTIVITY AND FECUNDITY IN ADULT FEMALE PERIPLANETA-AMERICANA, Journal of insect physiology, 39(6), 1993, pp. 499-502
Adult, female Periplaneta americana were topically treated with betwee
n 1.25-100 mug of fenoxycarb and their reproductive activity was subse
quently monitored for 6 months. Doses of greater-than-or-equal-to 2.5
mug of fenoxycarb significantly increased ootheca production for up to
4 weeks, but from about the tenth week onwards these animals tended t
o produce fewer oothecae than controls so that the total number of oot
hecae laid during the 6 months was not significantly changed by treatm
ent. Treatment of insects with 100 mug of fenoxycarb markedly reduced
the numbers and weights of nymphs emerging from oothecae laid during t
he first 4 weeks after treatment. Hatching and nymph weight were still
significantly reduced in oothecae laid 12-13 weeks after treatment, b
ut by the end of the 6 months there was no difference from controls. A
ll the nymphs successfully moulted into apparently normal second-insta
r larvae. Corpora allata were isolated from insects 13 weeks after tre
atment with 100 mug of fenoxycarb. When incubated in vitro, they showe
d significantly reduced rates of juvenile hormone biosynthesis compare
d with glands from control insects.