INTERAÇÃO BATATA E Diabrotica speciosa: METODOLOGIA PARA AVALIAÇÃO DE DANOS, REAÇÃO DE CULTIVARES E NÍVEL DE DANO

Abstract

Diabrotica speciosa is one of the main potato crop pests, causing perforations and galeries in the tubers and reducing the commercial value. For the management of this insect in potato crops, the selection of resistant cultivars is a promising strategy since there are few efficient methods of controls applicable in production systems. The objectives were to characterize the interaction of D. speciosa in tubers in potato cultivars, in field, laboratory and greenhouse evaluations, in addition to investigating possible mechanisms of insect resistance in these cultivars. A methodology for assessing insect damage to tubers was also tested. Losses caused by insects and other agents were characterized in post-processing of the tubers. For that, experiments were carried out evaluating the cultivars Ágata, EPAGRI-361-catucha, BRS-clara, IAC-Vitória and IPR-Cris, interacting with larvae and adults of D. speciosa under conditions of natural and artificial infestation. After evaluating the interactions and relationships of the pest with this crop, it was observed that the tolerance levels for the disposal of tubers, established for commercialization, must be reevaluated and defined for the classification of tubers based on external damage. Chemical management does not guarantee effective pest control, this has led to quality losses in the post-harvest product. None of the cultivars reached the damage that characterizes the disposal of the tuber according to the parameters recommended for classification, and EPAGRI-361-Catucha was little damaged by the larvae. Larval survival was affected by the four cultivars evaluated, however EPAGRI-361-Catucha caused higher larval mortality. The data obtained reinforce the need for further investigations in search of cultivars adapted to cultivations in organic systems and even the management of the pest in any system, as well as in the search for improvement in the ways of processing, classification and commercialization of potatoes.