Incidence of diapause in pink bollworm, Pectinophora gossypiella (Saund.)

Abstract

In Egypt, larvae of the first generation of Pectinophora gossypiella (Saunders) on cotton, which occur in July, do not go into diapause. In August, the larvae which enter diapause remain resting for a longer period than those which undergo diapause in subsequent months. The emergence of the majority of moths the following season from diapausing larvae occurs, therefore, within a short period and coincides with the first appearance of flower buds. There are two types of diapause, a short one lasting for an average of 42 days in 14.7 O/o of the larvae, and a long one lasting for an average of 184 in 85.3 O/o. The main diapausing sites are the dry bolls on cotton sticks stored on houses for fuel purpose, and infested bolls fallen and buried in the ground. If cotton sticks are used before cotton plants of next season start flowering infestation will be very much reduced. The fate of larvae buried in the ground is determined by the kind of crop which follows cotton in the rotation. Under clover, which is irrigated 10-12 times most buried larvae are killed; but under wheat which is irrigated 3 times most buried larvae can survive.

Development and diapause induction of the Indian meal moth, Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae) at different photoperiods

“…For instance, for the silk moth, Bombyx mori (L.), Shimizu 60 found that phosphatidylcholine of diapausing eggs contained more linolenic acid and less myristic acid than that of non-diapausing eggs. Similar reports have illustrated considerable differences between diapausing and non-diapausing individuals of the pink bollworm, Pectinophora gossypiella (Saunders), a feature linked to the timing of diapause termination 61,62 . The actual effect of the fatty acid composition on P. interpunctella larvae in diapause induction and termination is poorly understood, and requires additional investigation.…”

Biology of Diapausing Population of Pink Bollworm <i>Pectinophora gossypiella</i> (Saunders)

“…Prepupa was constructed at the base of plastic vial with a white thin cocoon layer rest on it, whereas, diapause larvae constructed a "hibernaculum" similar to that of prepupa but the cocoon layer slightly thicker; prepupal period was 2.75± 0.34 days in non-diapausing ones and a prolonged 93.2± 10.16 days with diapausing ones (Table 1). Zinzuvadiya et al (2017) observed this as 1.60± 0.52 and 1.65± 0.49 days in male and female, respectively; and Sapna et al (2014) as 1.95± 0.51 days at 25 o C. The period of diapause was 93.2 days, and Khalifa et al (1975) observed this to be 42-184 days; it was 60-116 days by Suresh et al (2001); Awaknavar (1976) as 56-120 days; Noble (1969) observed this as 2.5 years; and Ballou (1919) as months under Washington condition. Adults did not reveal any difference in the diapausing populations, but the longevity of male was 9.05± 0.55 and 9.75± 0.26 days, respectively in non-diapausing and diapausing ones without any significant difference; in female it was 9.55± 0.83 and 10.25± 0.43 days, respectively.…”