Pigeonpea Pod Wasp (Pod Borer Wasp)

📖 Description

Pigeonpea Pod Wasp (Tanaostigmodes cajaninae) is an important pod-feeding pest of pigeonpea across the Indian subcontinent, particularly severe in pigeonpea belts of Maharashtra, Karnataka, Andhra Pradesh, Telangana, Gujarat and Madhya Pradesh where pigeonpea is grown on over 4 million hectares. The adult female wasp lays eggs inside pigeonpea pods by inserting her ovipositor through the pod wall; the larva feeds inside the pod on developing seeds, causing shrivelled and deformed pods. The pest is particularly damaging because (a) it feeds inside pods where contact insecticides don’t reach, (b) it has a short life cycle (25-30 days) allowing multiple overlapping generations during the pod formation period, and (c) it is often not detected until pod damage is severe. Outbreaks are favoured by warm dry weather during pod formation and continuous pigeonpea cropping. The pest is most active during the post-monsoon pod formation period (October-January). IPM with neem-based sprays at pod formation, yellow sticky trap monitoring, conservation of native parasitoids (Eupelmus, Eurytoma — which parasitize pod wasp larvae), and need-based insecticide use provides effective control. The pest is particularly difficult to control because (a) it feeds directly on pods where contact insecticides don’t reach, (b) it has a relatively long life cycle (25-30 days), allowing multiple overlapping generations during the pod formation period, and (c) it has developed resistance to many insecticides. Early-maturing varieties that escape peak wasp pressure are an important preventive measure.