Impacts of abiotic factors and pesticide on the development, phenology, and reproductive biology of pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae)

Abstract

The pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae) is a serious insect pest of cotton crop. The studies to evaluate the impact of abiotic factors on cotton pests’ biology are limited. The current study was undertaken to determine the impact of abiotic factors (temperature, humidity, photoperiod) and an insecticide (lambda-cyhalothrin) on the biological aspects of P. gossypiella. The results revealed that all the treatments showed a significant impact on different life parameters of P. gossypiella. The temperature exposure at 27 °C revealed a total life span of about 33 days. Maximum mortality for larvae (51.11%), pupae (59.04%) and adults (61.92%) were recorded at 33 °C exposure. Both low and high humidity levels caused negative impacts on life parameters of P. gossypiella. The life span was completed in about 30 days at 60% relative humidity (RH). Maximum mortality for larvae (75.00%) and pupae (49.59%) were recorded at 80% RH level exposure, while adult mortality was maximum (63.09%) at 40% RH level followed by 80% RH level (55.52%). The P. gossypiella exhibited a life span of about 32 days at 14:10 light-dark period. The larval mortality was maximum (14.83%) at 12:12 light-dark period while pupal (47.36%) and adult (48.84%) mortality was maximum at 16:08 light-dark period. Lambdacyhalothrin (LC) showed dose dependent negative impacts on biological aspects of P. gossypiella. The P. gossypiella exhibited a life span of about 26 days at 0.5 ppm LC concentration. The P. gossypiella exposure to highest concentration (LC) revealed maximum mortality of larval (80.22%), pupal (64.63%) and adult (70.74%) stages. Conclusively, the best suited abiotic factor ranges were 27 °C (temperature), 60% (RH) and 14:10 (light-dark) which can be used for successful rearing and bioassay activities of P. gossypiella.

Keywords

• Pink bollworm
• Cotton
• Temperature
• Relative humidity
• Photoperiod
• Pesticides