Damage and larval development of anastrepha fraterculus (Diptera, tephritidae) in fruits of two kiwi cultivars (Actinidia spp.)

Abstract

The damage caused by A. fraterculus in three ripening stages of kiwi were evaluated in commercial orchards and, in laboratory, larval development of this species was studied in cultivars MG06 and Bruno. Fruits of both cultivars were infested with A. fraterculus in orchards at Farroupilha-RS, in the beginning (30% of their final size), middle (30% of their final size) and end (harvest point) of the cicle, and, in laboratory, since the beginning of fruiting until harvest. Three days after the first infestation in cultivar MG06, we observed the formation of a crystalline exudate in puncture sites that evolve at harvest to cracks, depressions and beginnings of galleries. Also, fibrosis were observed in fruits infested at the end of the cicle (harvest point) in the same cultivar. Although the eggs have been counted, at field, there was no larval development on MG06 fruits. Damage and oviposition weren't found at Bruno, indicating the immunity of this cultivar. There was no fruit drop attributed to A. fraterculus in both cultivars. In laboratory, larval development was observed when the fruits had, at least, 6.4 % (MG06) and 7.0 % (Bruno) of total soluble solids.