RELEASE OF THE PARASITOID Cotesia flavipes HYMENOPTERA: BRACONIDAE) ON Diatraea saccharalis (LEPIDOPTERA: CRAMBIDAE) IN A SUGAR CANE PLANTATION

Diatraea saccharalis (Lepidoptera: Crambidae) is considered as one the most important pest for sugarcane plantations. Biological control, through the release of Cotesia flavipes (Hymenoptera: Braconidae), is the most efficient means of controlling this insect pest. However, several factors can affect the performance of the natural enemy, being the temperature one o f the most important. In sugarcane plantations, great oscillations of temperature can be observed during the time of release of C. flavipes. The aim of the work was to ascertain the degree of parasitism by two strains of this parasitoid at the different times of release that are used by the farmers and identify the best liberation moment. Internodes of sugarcane containing fourth instar caterpillars of D. saccharalis were distributed among plants in a cane field, and parasitoids were released at different times (6:00, 7:00, 8:00, 9:00 and 10:00). The internodes remained in the field for 24h. After this period, all of them were taken to the laboratory to evaluate the parasitism. The highest rate of parasitism was observed when inside of the sugarcane plantation the medium temperature was 24 degrees C and the release was done between 7.00 and 9:00.