Larvicidal and Adulticidal Activities of Neem Oil against Anastrepha fraterculus (Wied.) (Tephritidae)

In the laboratory, a neem oil-based formulation was evaluated for its insecticidal potential against the South American fruit fly Anastrepha fraterculus (Wied.), as efficient alternative for growers harvest fruits more harmless for the human consumption. The commercial product was evaluated against eggs in vitro, guavas infested with eggs and young larvae, and adults. The application of 0.8% neem oil significantly reduced the larval hatching of A. fraterculus. Neem oil at 0.4, 0.6 and 0.8% significantly reduced the number of pupae and adults per fruit infested with eggs. Guava infested with A. fraterculus eggs and treated with neem oil at 0.8% exhibited a reduction of 90.0% and 92.6% of pupae and adults per fruit, respectively. The same dosage to guava infested by larvae achieved a 44.6 and 51.4% reduction of pupae and larvae, respectively. At 360 minutes after treatment, 0.8% of neem oil provided 67.9% of corrected adult mortality. This double insecticidal effect of neem oil and lack of phytotoxicity in ripe guavas at the tested concentrations demonstrate its potential in biorational management.