Non-destructive control of the bat, Cynopterus sphinx Vahl (Chiroptera: Pteropodidae) in grapes (Vitis vinifera Linnaeus) in India.
Verghese A.
Author Affiliation: Indian Institute of Horticultural Research, Hessaraghatta Lake PO, Bangalore 560 089, India.
International Journal of Pest Management 44 : 81-85
Abstract : The bat Cynopterus sphinx seriously damages grapes in India. Foraging ecology and non-destructive control of the bat was studied at Bangalore, Karnataka, India. Bat damage was found to be positively correlated with fruit maturity and it begins at least a fortnight prior to harvest, when fruits start maturing. Peak damage was recorded 8 days prior to harvest. Damage was significantly higher where open space, adjacent to the vineyard, was available and lower on the vines closest to a mango orchard, 10 m away from the vineyard. It was inferred that growing trees around the vineyard may deter bat foraging. Erecting around-bower nylon netting (5 × 5 cm, mesh) from ground level to bower height did not prevent bat damage. In addition to erecting around-bower netting, erecting within-bower netting (in a zigzag manner) to obstruct flight within the orchard also did not appreciably reduce the bat damage. This study also showed that vines closer to open space had more bat damage than vines which were adjacent to physical barriers such as trees and mango orchards. The best management strategy was found to involve erecting the nylon netting around-bower plus covering canopy gaps on the bower with twigs and briers; this gave effective control of the bat in four seasons of trial. This treatment is both non-destructive and cheap. The bat's useful role as a pollinator of forest trees is thus not compromised.