Monitoring based simple and effective mechanical management strategy for grapevine stem borer, Celosterna scabrator

This research proposes a practical, non-chemical management strategy based on regular monitoring and mechanical removal of grubs for managing grapevine stem borer, Celosterna scabrator (Coleoptera: Cerambycidae), a major pest affecting grapevines in India. It was developed and validated at farmers’ vineyards between February 2020 to April 2022 in the grape-growing regions of Nashik and Osmanabad, Maharashtra. The monitoring was carried out at 10 days interval during December to April to observe two symptoms, viz., (i) appearance of a wet patch on the main trunk or cordon during early morning hours, (ii) initiation of presence of frass near the plant. The mechanical removal of C. scabrator grubs was done using wire, screwdriver or scissors. This strategy was evaluated at Nashik and Osmanabad during October 2021 – April 2022 in two farmer vineyards and the initial level of infestation was 12.25 and 22%, respectively. The strategy provided 100% control of C. scabrator and resulted in yield statistically at par with healthy vines and significantly superior over infested untreated vines. This strategy was validated as farmer-participatory approach in seven C. scabrator infested vineyards at Sarole Khurd, Nashik and the level of infestation ranged from 6.15 to 20.35% before imposing the management. After following this strategy for two fruiting seasons during 2020-21 and 2021-22, the infestation level ranged from 0.17 to 0.55% during 2022 resulting in total 96.84% infestation reduction. By focusing on early pest detection and non-chemical intervention, this strategy offers an economically viable solution to grape growers.