Responses of Anastrepha fraterculus (Diptera: Tephritidae) to pesticides used in organic fruit production

The South American fruit fly, Anastrepha fraterculus (Diptera: Tephritidae), is an economically important pest of fruit production in Southern Brazil. In organically managed orchards the species has traditionally been controlled with oils, plant extracts, and solutions such as pyroligneous extract and lime sulfur. The objectives of this study were to examine the possible deterrent effect of pesticides with the highest electroantennographic bioactivity on fruit flies and to assess their effects on the viability of pupae in treated fruits. Antennae were exposed to pyroligneous extract (BioPirol7M®, 0.4%), lime sulfur solution (SulFertilizantes, 1%), neem (Organic Neem®, 0.5%), and rotenone (Rotenat®, 0.6%), taking into account fly sex, age and reproductive status. Pupal viability was assessed for larvae reared in papaya (Carica papaya var. Calyman) and guava (Psidium guajava var. Paluma) fruits treated with the pesticides that generated the strongest electrophysiological responses. The bioactivity of A. fraterculus antennae was highest when stimulated with pyroligneous extract and lime sulfur solution, for young and mated flies. Neither substance inhibited oviposition and larval development in treated fruits, a result that has important implications for A. fraterculus management in organic systems.