Efficacy of promising insecticides and lures for the management of insect pests of quarantine importance on ridged gourd (Luffa acutangula L.)

Abstract

Insecticides play an important role in the management of insect pests on ridged gourd (Luffa acutangula L.) or turia. The sweet potato whitefly, Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae), thrips, Thrips spp. Karny (Thysanoptera:Thripidae), and fruit flies, Zeugodacus cucurbitae (Coquillett) and Bactrocera dorsalis (Hendel) (Diptera:Tephritidae) are the commonly found insect pests on turia in Ghana. These insect pests have been intercepted in some vegetables including turia exported into the European Union. The current study evaluated the efficacy of promising insecticides and lures for the management of these pests of quarantine importance on turia. The study was undertaken at a vegetable production site at Torgorme in the Volta region of Ghana during the dry and rainy seasons of 2017 and 2018, respectively. The experiment was laid out in a Randomized Complete Block Design with five treatments replicated four times. The treatments included use of Eradicoat T GH^® (Maltodextrin 282g/L) at 150 ml per 15L of water, Ecopel^® (Bacillus thuringiensis 32000 IU/mg at 25g/15L of water, Aqueous Neem Kernel Extract (ANKE) (Azadirachtin) at 50g/L of water, and Viper^® (Acetamiprid 16g/l + Indoxacarb 30g/l ) at 40ml /15L of water, and untreated control plot. Fruit fly traps with different pheromones or lures (i.e., Methyl Eugenol, Cuelure, Terpinyl Acetate and Trimedlure) were set at the four corners of the field to monitor the different species of fruit flies. Yellow sticky traps were also set within treatment plots to monitor pest populations. Whitefly population was significantly different among the treatments for both cropping seasons, while fruit fly population was not significant for both seasons. There was a significant difference in thrips population for the rainy season, however, it was not significant in the dry season. In a descending order, Acetamiprid 16g/l + Indoxacarb 30g/l and Azadirachtin were the most effective insecticides in controlling these pests on turia. There is, therefore, the need to alternate these two insecticides for effective management of pests on turia.