Effectiveness of Three Insecticides to ControlBactrocera cucurbitae(Diptera: Tephritidae) on the Cucumber Crop at Praslin, Seychelles

A field experiment was conducted from Oct to Dec in the 2009 and 2010 planting seasons at the Vegetable Evaluation and Research Sub-Station farm located at Praslin, Seychelles to evaluate the effectiveness of 3 insecticides namely lambda-cyhalothrin, deltamethrin and mercaptothion, to control the melon fruit fly (Bactrocera Cucurbitae) in the cucumber crop. The 3 insecticides constituted the treatments, replicated 4 times in a randomized complete block design. The results obtained showed that the use of deltamethrin insecticide recorded the lowest number of ovipositor marks, number of pupae and number of emerged melon fruit flies. The number of melon fruit flies that emerged with the use of deltamethrin insecticide was significantly (P ≤ 0.05) decreased by 19.0% and 38.1%, respectively, in 2009 and by 10.0% and 44.4%, respectively, in 2010 compared to that recorded with the use of lambda-cyhalothrin and mercaptothion. The highest number of marketable cucumbers was produced from plots sprayed with deltamethrin; and which was significantly (P ≤ 0.05) increased by 50.5% and 62.9%, respectively, in 2009 and by 29.0% and 50.7%, respectively, in 2010 compared to those obtained when lambda-cyhalothrin and mercaptothion were used. This study showed that deltamethrin insecticide was the most effective, and could be recommended for the control of melon fruit fly in cucumber under field conditions.