Associação entre inseticidas e Trichogramma pretiosum (Hymenoptera: Trichogrammatidae) para o controle de broqueadores dos frutos do tomateiro

Abstract

Tomato is one of the most produced vegetables in the world and its production chain generates many jobs and income. Of the several problems faced in the plantations, the pest stand out and among them, the fruit borers are considered important pests because they cause damages directly on the fruits, precluding their commercialization. The main method to control these insects is the use of chemical insecticides, but biological control using parasitoids Trichogramma spp. (Hymenoptera: Trichogrammatidae), has been showing good results and the association these methods can reduce the number of applications and improve the efficiency of the pests control. In view of the above, the objective was to evaluate the efficiency of insecticides and their interaction with T. pretiosum in the control of Lepidoptera borer fruits of tomato. The experiment was carried out in the municipality of Guaraciaba do Norte, Ceará State, in an area of conventional cultivation where were applied the treatments: Clorfenapir (50 ml/100L) + Limoneno Extract (250ml/100L); Metaflumizone (100ml/100L) + Quillay Extract (200ml/100L); T. pretiosum (100.000 individuals/ha); T. pretiosum + insecticides rotation and one control treatment (without application). In the production area under organic system, releases of T. pretiosum were made (100.000 individuals/ha). The products were applied with the aid of a 10 L costly sprayer and the parasitoids used were created and prepared for release at the “Laboratório de Entomologia Aplicada” of the UFC. The experiment was set up in a completely randomized experimental design (CRD). The presence of pest eggs and the number of parasitized eggs were evaluated before, 24 and 96 hours after the treatments. Data were submitted to the F test (ANOVA) and, when significant, averages were compared by the Duncan test (5% probability). Only Neoleucinodes elegantalis (Lepidoptera: Crambidae) caused damage to the fruits. In the plot where only T. pretiosum was released, 21.8% of damaged fruits were observed, being the smallest percentage. In the plot where Clorfenapir + Limonene Extract was applied, 26.2% of damages were even greater than in the control. Even with the use of insecticides, the egg parasitism of N. elegantalis by T. pretiosum occurred in all treatments, indicating a possible association between these control techniques.