Evaluation of optimum heights of pheromone trap on attraction of fruit flies (Diptera: Tephritidae) in cucumber in North Eastern India

Melon fruit fly, Bactrocera (Zeugodacus) cucurbitae (Coquillet) (Diptera: Tephritidae) is a serious pest of cucurbitaceous vegetables in Bihar and cucumber is the most preferred host of the pest. The purpose of the current study was to identify the optimum height of trap to capture maximum number of fruit flies. The results showed that the maximum mean number of fruit flies (25.31 flies per trap per day) was caught in trap at a height of 35 cm and it was followed by 70 cm (19.29 flies per trap per day), whereas, the minimum (15.97 and 13.37 flies per trap per day) were caught at the height of 105 and 140 cm. Correlation study revealed that the height of the traps had highly significant and negative correlation (-0.980**) with number of fruit flies catches per trap at weekly interval, which indicates that the maximum fruit fly catches were obtained near the ground level where the fruit lies. Four species of fruit flies were trapped in the pheromone traps: B. cucurbitae, B. caudata, B. tau and B. nigrofemoralis . These present findings suggest that for the monitoring of fruit flies, the cuelure (p-acetoxyphenyl 2 butanic) traps should be hanged at the height of 35 cm from ground level to get the maximum counts of fruit flies.