Plant Extracts as Oviposition Deterrents against Fruit Flies, Bactrocera spp. Infesting Vegetable Crops

Fruit flies, Bactrocera tau (Walker) and B. cucurbitae (Coquillett), devastating pests of tomato and cucurbits respectively, lays eggs inside the fruits rendering them inaccessible for any control measure. Laboratory studies on the oviposition deterrent effect of ethanol extracts of Melia azedarach L., Lantana camara L., Allium sativum L., Curcuma longa L. and a commercial formulation of Azadirachta indica 300 ppm against B. tau and B. cucurbitae on cucumber and tomato fruits, each at 1, 2 and 3 per cent concentrations by fruit dip method revealed a similar trend of deterrence against both the species, highest being in the treatment with A. indica with an average of 88.7 and 90.1 per cent deterrence against B. cucurbitae and B. tau respectively, over control. The oviposition deterrent effect increased with an increase in concentration; being maximum at 3 per cent against both B. tau (85.3%) and B. cucurbitae (86.6%).