Phenological asynchrony between the fruit fly Anastrepha fraterculus and early maturing peach cultivars could contribute to pesticide use reduction

Abstract

Phenological asynchrony between fruit crops and pests consists of a discrepancy between the period of fruit susceptibility and that of high pest abundance in the orchards. Therefore, it may be used for reducing pesticide applications. We assayed the potential phenological asynchrony between peach cultivars with different growing cycles and the Anastrepha fraterculus (Diptera: Tephritidae). To this end, we assessed fruit infestation by A. fraterculus at harvest for one growing season (2012-2013) in early, average and late maturing peach cultivars. Moreover, the fruit infestation was checked for non-cultivated native and non-cultivated wild exotic plant hosts around the peach orchards of the experimental area during 2013 and 2014. In addition, we monitored A. fraterculus abundance weekly during three consecutive growing seasons, S1 (2011-2012), S2 (2012-2013) and S3 (2013-2014), to assess phenological asynchrony between peach cultivars and A. fraterculus. In particular, we checked the influence of meteorological variables on A. fraterculus abundance, and tested if A. fraterculus abundance at the time when fruits are susceptible differed among cultivars. Eventually we discuss the possibility of sustainable management of peach in southern Brazil. This study constitutes a first assessment of the periods of crop vulnerability and pest presence in peach orchards in South of Brazil and provides necessary information for taking advantage of the phenological asynchrony phenomenon for this pest-crop association.