Biology of pink bollworm Pectinophora gossypiella (Saunders) on cotton as influenced by temperature

Abstract

A laboratory experiment was conducted to study the biology of pink bollworm Pectinophora gossypiella (Saunders) on cotton at four different temperature levels. It was found that males have a considerably shorter total life cycle duration on cotton at 35±1°C (29.5 days) followed by 30±1°C (37.2 days), 25±1°C (46.9 days) and highest at 20±1°C (50.8 days). Similarly, minimum total life cycle duration of female P. gossypiella was recorded at 35±1°C (30.2 days) followed by 30±1°C (38.0 days), 25±1°C (47.3 days) and maximum at 20±1°C (51.7 days). The highest fecundity was observed at 30±1°C (106.2) followed by 25±1°C (100.1), 35±1°C (60.1) and lowest at 20±1°C (55.2). Male as to female sex ratio was highest at 35±1°C (1:1.5) followed by 25±1°C (1:1.4), 30±1°C (1:1.3) and lowest at 20±1°C (1:1.2). These findings revealed that variation in temperature significantly influences the life cycle duration, fecundity and sex ratio of pink bollworms on cotton, with higher temperatures accelerating development and enhancing reproductive success.