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Many different factors can influence the survival of the early stages of Lepidoptera. The mortality of the early stages of H.armigera was measured in the field and in the glasshouse in 1987 and 1988. Egg losses were high (35.7-58.8%) from day 1-3 and mortality in the 1st larval instar was as high as 92.8-100% on day 4-5 (1987 Trials). The mortality factors were wind, rain (watering), aerial predators, 1st instar dispersal and host plant effects. Comparison between cotton varieties indicated there were no significant differences. The losses of eggs on the lower surface was higher than the upper leaf surface. The losses of 1st instars was higher in seedling stage cotton than on squaring cotton. The losses of eggs in T2 (watering or rain and leaf position treatment), T3 (wind and leaf position treatment), and T4 (all combined - watering, wind and leaf position treatment) plants were 19.11-32.0%, 14.49-32.0%, 22.92-52.0% respectively on day 1 in the field trial of 1988. In the glasshouse trial of 1988, the losses in T2,T3,and T4 treatments were 3.85-22.0%, 4.0-31.0%, and 24.78- 38.0% on day 1. The mortality of 1st instars was 29.5%, 68.23%, 73.9%, 58.7%, and 58.33% in T,T1,T2,T3, and T4 treatments in field trial of 1988. In the glasshouse trial of 1988, the mortality of 1st instars was 25.51%, 31.31%, 46.46%, 39.58%, and 20.0% in T,T1,T2,T3, and T4 treatments. The highest losses of eggs and 1st instars occurred on day 1 and day 4 in both trials in 1988. Wind, rain (watering), and all factors combined affected the early stages of H.armigera in both trials. The mortality of 1st instars was related to host plant effects.
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