Monitoring and Management of Fruit Fly, Bactrocera dorsalis (Hendel) in pear (Pyrus communis L.) in the Shevaroy Hills of Tamil Nadu

Abstract

A field experiment was conducted during 2024–25 in a farmer’s pear orchard at Manjakuttai, Yercaud, Tamil Nadu, to monitor the seasonal abundance of Bactrocera dorsalis (Hendel) in pear (Pyrus communis L., Var. Local) and compare an integrated pest management (IPM) module with the farmer’s chemical control practice and an untreated control. The experiment followed a randomised block design with three treatments and seven replications. Adult activity was monitored weekly with ten methyl eugenol–baited parapheromone traps during standard weeks (SW) 7–16 (12 February–22 April 2025). Trap catches increased from 13 to 22 flies/10 traps during SW 7–11, stabilised at 18–19 during SW 12–13, declined to 11 and 9 during SW 14–15, and increased to 28 during SW 16. Minimum humidity showed the strongest association with trap catches (r = 0.7989, p = 0.0056), explaining 63.83% of the variation in the simple regression. Maximum humidity, rainfall, minimum temperature, and maximum temperature showed positive but non-significant correlations over the full monitoring period. The five-variable regression explained 97.79% of the observed variation, although the estimate is based on only ten weekly observations. Cumulative rainfall of 63.2 mm during SW 14–16 coincided with the final population resurgence. The findings indicate that adult B. dorsalis is present before pear fruiting and support early monitoring and timely IPM intervention. Harvest-stage fruit damage, yield, and benefit–cost data were still pending during the reported monitoring period.