Results concerning the effect of sonic ecological factors on the
diapaused larvae of pink boliworm (PBW), Peclinophora gossypiella indicated
that, when the diapaused larvae were picked from cotton seeds and examined, it
was found that the rate of dead to alive larvae amounted (65. 5%:34.5%) and
(39%:61%) during 1994/95 and 1995/96 seasons, respectively. Mortalities were
due to natural mortality, bacterial & viral infections and effect of the parasitoids
Pyemotes herfsi and Plinpia rob orator. Accumulation of low heat units raie has
worked as larval mortality factor and it is important for timing and determining
the size of PBW spring emergence. Results of biological and histological effects
of the bioinsecticide (xentari) on the spiny boliworm (Earias insulana) — neonate
larvae showed that xentari displayed latent effects during the subsequent stages.
The achieved effects were: death in the various larval inslars due to feeding the
neonate larvae for 2 days on contaminated artificial diet increase of larval and
pupal duration and decrease of adult longevity and the number of deposited eggs
per female in comparisoi to untreated check.
Feeding the 4’ instar larvae of E. insulana on contaminated diet with
xentari caused certain pathological effects in the mid-gut of the treated larvae.
Cross sections of the mid-gut showed separation of the epitlielial cells from the
basement membrane as well as elongation, vaculization and breakdown of larval
epithelium mid-gut. Also, xentari caused disorganization and disintegration of
preirophic membrane.
Keywords: Bollworms — Bioinscclicide — Ecological factors.