Efeito da densidade e da idade de ovos de Neoleucinodes elegantalis (Guenée) (Lepidoptera: Crambidae) sobre parâmetros biológicos e exigências térmicas de Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae)

Abstract

The tomato fruit borer, Neoleucinodes elegantalis is the major pest of tomato, which can reduce the production by over 50%. Chemical control is widely used, but the behavior of neonate larvae, which penetrate rapidly in fruits, hamper contact with insecticides. An alternative is the use of Integrated Pest Management, involving selective insecticides, environmental management practices and parasitoids of the genus Trichogramma. The study aimed: to evaluate the occurrence of species Trichogramma in Bezerros and Camocim de São Felix, Pernambuco; to evaluate the effect of density and egg age of N. elegantalis in tomato fruits and cards on biological aspects of T. pretiosum at different temperatures. The best results were reached in eggs exposed on tomato fruit. There was significant difference in sex ratio at densities of 25 and 35 eggs, between fruits and cards. The longevity presented significant difference in all egg densities in fruit and cards. The parasitism reduced when increased the egg age of N. elegantalis. Parasitized eggs 24-48 h allowed 98.75% of emergence. The egg age didn't influence sex ratio, but the adult longevity ranged from 2.96 to 4.23 days. With increase temperature occurred reduction in the periods of egg-pupa, pupa-adult and egg-adult of T. pretiosum. The egg parasitism on N. elegantalis ranged from 30.1% (33 °C) to 78.8 (25 °C). The temperature of 28°C allowed 100% of parasitoids emergence. The sex ratio was not affected in any temperature and longevity reduced with increase temperature. The lower threshold temperature for the period egg-adult of the parasitoid was 9.9 °C and its respective thermal constant of 155.5 degree days.