Pattern of Pink Bollworm Diapaused Larval Exit from the Last Season Cotton Bolls and Their Biological Parameters

Abstract

The present study was carried out to investigate the patterns of pink bollworm (PBW), Pectinophora gossypiella, diapaused larval exit from cotton bolls, percent larval mortality after leaving bolls and the development as well as some biological parameters of living larvae. Diapaused larval exit began at March and the number of emerged larvae from immature green cotton bolls that collected from El-Behira (ranged from 22.3 to 106.7 larvae) is significantly higher than the number of emerged larvae from immature green cotton bolls that collected from Alexandria (numbers ranged from 17.7 to 82.3 larvae) during the investigated period. Percent larval mortality in exited larvae at March, April and May from Alexandria cotton bolls (70.3, 64.7 and 52.1%, respectively) is significantly higher than the percent larval mortality from El-Behira (66.5, 57.8 and 46.4%, respectively). The PBW %adult emergence in El-Behira strain is significantly higher than the PBW percent of adult emergence in Alexandria strain during March and April. Fecundity (No. laid eggs / female) and fertility (percent egg hatching) are significantly higher in the moths which emerged from ElBehira strain than from Alexandria strain. This study represents important information about the pattern of PBW diapaused larval exit from the last season cotton bolls which can help in the PBW infestation prediction and mangement.