Little-Known Pest, Euproctis lunata (Lepidoptera: Erebidae) of Castor Plants: Insights into Its Biology and Sustainable Management Using Entomopathogenic Fungi

Abstract

The castor hairy caterpillar, Euproctis lunata Walker (Lepidoptera: Erebidae), a least-known defoliating pest of castor plants (Ricinus communis), has recently gained attention due to considerable losses of castor plants in Pakistan. Pakistan lacks a comprehensive investigation of this insect pest, resulting in a significant knowledge absence about its biology, effects on castor crops, and sustainable management strategies. We determined the developmental biology of E. lunata on castor plants and studied the potential of entomopathogenic fungi, Metarhizium anisopliae and Beauveria bassiana to control larvae of this pest. Larvae were grow through six instars, with a total duration of 21.4 days. The pupal stage was completed in 12.4 days, and adult moths lived for 5.10 days. Pathogenicity trials showed higher virulence of B. bassiana against E. lunata larvae compared to M. anisopliae. At a concentration of 109 conidia/mL, B. bassiana caused 87.5% larval mortality up to 15 days, while M. anisopliae induced 80.0% mortality. Further, probit analysis confirmed B. bassiana as a potent pathogenic fungus, with a lower LC50 value of 1.4 × 105 conidia/mL and LC90 of 6.1 × 109 conidia/mL. The findings provide useful information about E. lunata biology and highlight the potential of B. bassiana fungus for eco-friendly and sustainable management of this pest. Future studies should include extensive field surveys to map the distribution and infestation levels of this pest on castor plants and nearby cropping systems across diverse agro-ecological zones of Pakistan.