Caracterização de duas pragas emergentes em fruteiras com potencial de cultivo no sudoeste do Paraná: Palpita sp. em oliveiras e Paraulaca dives em feijoa

Abstract

Olive (Olea europaea) and feijoa or guava-serrana (Acca sellowiana) cultivation have been tested in recent years in the experimental orchard of the UTFPR Campus Pato Branco. In these experimental cultures the presence of two pest insects causing defoliation became recurrent, the caterpillar Palpita sp. in olive tree and the beetle Paraulaca dives in feijoa. Because these two fruit species have potential for cultivation in the Southwest region of Paraná, the adaptation studies should include the quantification and characterization of damages and pests and also alternative forms of control, since there are no registered insecticides for this. The objectives of this work were to identify and characterize the food behavior, damages, incidence and temporal and spatial distribution and alternative control of the caterpillar Palpita sp. in olive tree and the beetle Paraulaca dives in feijoa. The evaluations were carried out in an olive orchard composed by the cultivars Koroneiki (66%) and Arbequina (33%) and another feijoa orchard, which is a progeny test from the Epagri of São Joaquim, Santa Catarina. The moth, adult of the caterpillar of the olive trees, was identified as being of the species Palpita forficifera Monroe, 1959 (Crambidae, Spilomelinae). Caterpillars caused damage on new leaves and pointers of new shoots, especially during the summer months (December to March). They presented a random distribution in the orchard, not following a pattern of incidence, but had food preference for Arbequina olive cultivar (63.5% of the number of caterpillars), despite the smaller number of plants in the orchard in relation to the cultivar Koroneiki. The application of neem oil (7% Azadirachtin indica) and Bacillus thuriengiensis, under laboratory conditions, were efficient in the control of P. forficifera, causing 100% mortality of second instar caterpillars, until 48 hours after application, while Metarhizium anisopliae and Beauveria bassiana had lower efficiency. The beetle Paraulaca dives attacks leaves, flowers and feijoa fruits, with incidence during the spring months (October to December). The main damage is the herbivory of young and old leaves, with average foliar losses of 16%, reaching up to 55%. The diagrammatic scale elaborated allowed the evaluation of herbivory damage in a more precise and accurate way, in relation to the evaluation of the severity in which the evaluators did not use the scale. The beetles were also randomly distributed in the feijoa orchard, without following any clear patterns of population distribution. The use of B. thuringiensis or neem oil may become tools of alternative and integrated control of P. forficefera in olive orchards, but field control tests still need to be performed. In Pato Branco, the control of these two insects should be done at the beginning of the infestation, which occurs in December for the caterpillar-of-olive trees, and in October for the beetle in feijoa. The diagrammatic scale proposed in this work may be useful for future evaluations of the herbivory severity of P. dives in feijoa.