Hadronotus pubescens (Motschoulsky) (Hymenoptera, Scelionidae): Redescription, biological attributes, and parasitism on eggs of Riptortus pedestris (Fab.) (Hemiptera, Alydidae)

Abstract

Riptortus pedestris (Fab.) (Hemiptera, Alydidae) is one of the most damaging insects of leguminous crops in Eastern Asia but has only recently emerged as a pest in Bangladesh. Eggs, nymphs and adults of R. pedestris are here reported from mung bean (Vigna radiata (L.)) fields in Bangladesh. Two parasitoid species were reared from field-collected eggs of R. pedestris, the solitary Hadronotus pubescens (Motschoulsky) (Hymenoptera, Scelionidae) and a gregarious species of Ooencyrtus Ashmead (Hymenoptera, Encyrtidae). Here we redescribe H. pubescens, treat H. hogenakalensis (Sharma) as a junior synonym, and report aspects of its biology that were investigated under laboratory conditions. The number of eggs parasitized by H. pubescens was constant with eggs up to 48 hours in age, decreasing by 14% for 96 hour-old eggs. As host egg age increased, the parasitoid mean development time increased and the longevity of the parasitoids decreased.