Effect of aqueous neem seed extract via irrigation on larvae of Liriomyza sativae in melon crop

ABSTRACT The leafminer [Liriomyza sativae (Diptera: Agromyzidae)] is one of the main pests of melon crop (Cucumis melo) in the states of Rio Grande do Norte and Ceará. Thus, adopting strategies to control this destructive insect is essential. The aim of this study was to evaluate the effect of aqueous neem seed extract, applied to soil via irrigation, on leafminer larvae, in the melon crop. An experiment was conducted in greenhouse, in completely randomized design, consisting of five treatments (four doses of aqueous neem seed extract: 1; 3; 5 and 10 g/100 mL) and the control consisting only of distilled water and 10 replicates (melon plants). The treatments were applied in a single dose, via soil irrigation. In the first stage of the evaluation, 24 hours after application, the number of dead larvae per plant was counted. In the second step, pupal mortality was recorded. The total mortality was also calculated considering the number of larvae and the number of emerged adults. We verified that, increasing the concentration of aqueous neem seed extract, an increase in the larval and pupal mortality of the leafminer in melon crop was noticed. The concentration 10 g/100 mL presented the best results, resulting in 36.4% of larval mortality, 96.5% of pupal mortality and 96.8% of total mortality.