Description

Chlorfluazuron was applied topically to newly
moulted fifth-instars, a significant reduction in
both number of eggs laid and subsequent hatching was
observed after mating. Number of unfertilized eggs
was greater than those were fertilized, but
significantly more unfertilized eggs laid by treated
insects. Interference by chlorfluazuron, transferred
by copulation through sperm fluids or ova, appeared
improbable. Injection of haemolymph of moths
resulted in increased in oviposition within first 24
h. Two factors were involved in activation of
ovipositon: OSF-I was found in virgin females,
whereas OSF-II may be formed or received by males
during mating. Chlorfluazuron decreased activities
of OSFs by significantly decreasing oviposition.
Unfertilized-dead eggs remained green and no morpho-
embryological changes were observed under the
microscope during 0 84 h. On the basis of
microscopic examination of prepared slides of eggs
were characterized into 8 stages during embryonic
development of 0 84 h after oviposition in S.
litura. LD10-treated embryos were affected
significantly and LD30-treated embryos were affected
more significantly during their development.