Oviposition and feeding preferences of adult females of Henosepilachna pusillanima (Coleoptera: Coccinellidae) for the leaves of different host plants

Author of the article:LI Qian** ZHANG Ya-Jing** DAN Jian-Guo***

Author's Workplace：Institute of Tropical Agriculture and Forestry, Hainan University, Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou 570228, China

Key Words： Henosepilachna pusillanima; cucurbitaceous plants; oviposition; trenching; feeding

Abstract： [Objectives]  To evaluate the oviposition and feeding preferences of adult female Henosepilachna pusillanima (Mulsant) (Coleoptera: Coccinellidae), an economic pest of cucurbitaceous vegetables, for the leaves of squash (Cucurbita moschata), cucumber (Cucumis sativus), and ridged gourd (Luffa acutangula). [Methods]  Adults and larvae of H. pusillanima often exhibit trenching behavior prior to feeding on leaves. Under laboratory conditions of (26±1) ℃, 60%±5% RH and a photoperiod of 14L: 10D, one 24-h-starved gravid female was exposed to the top five leaves of a plant counted basipetally from the growing point. After 24 hours, the number of eggs, the trenched area and the feeding area, were determined on the adaxial and abaxial surfaces of each leaf. Oviposition, trenching, and feeding preferences for different leaves and leaf surfaces were recorded. [Results]  Adult female H. pusillanima fed exclusively within trenches cut by themselves on leaves. Among the three cucurbitaceous vegetables tested, both the total daily trenched area and feeding area per female were smallest on squash. The oviposition preferences for abaxial or adaxial leaf surfaces varied depending on host plant species, but females strongly preferred the abaxial leaf surfaces on all three host plants fir trenching or foraging. Females did not prefer 1^st and 2^nd leaves for oviposition. Although females preferred the 2^nd and 3^rd leaves of both squash and ridged gourd for trenching and foraging, they did not have any clear preference for specific leaves on cucumber. [Conclusion]  Adult females did not prefer young leaves for oviposition, and preferred abaxial leaf surfaces for trenching and feeding.