Capacidade de parasitismo de Trichogramma pratissolii Querino & Zucchi (Hymenoptera: Trichogrammatidae) em hospedeiros alternativos, sob diferentes temperaturas

Abstract

The successful use of Trichogramma as biocontrol agent depends on its mass production in laboratory, a fundamental step for any biological control program among other factors. This work investigated the parasitism capacity of Trichogramma pratissolii Querino & Zuchi (Hymenoptera: Trichogrammatidae), a new recorded Trichogramma species, parasitizing eggs of Anagasta kuehniella (Zeller) and Corcyra cephalonica (Stainton) (Lepidoptera: Pyralidae) under the temperatures of 15, 18, 21, 24, 27, 30 and 33°C. Eggs of these hosts were offered to newly emerged females during 24h. This procedure was repeated daily for each female and each temperature up to female death, in order to estimate daily and accumulated parasitism, and female longevity. On both hosts, the daily parasitism decreased as function of the female age. Under all temperatures studied and both hosts the highest rate of parasitism was observed during the first 24h of host exposure, and reached 80% of total parasitism in the 4 th and 3rd days when parasitizing A. kuehniella and C. cephalonica, respectively. On both hosts, the highest parasitism rate was observed under temperatures from 21°C to 27°C. Average longevities of T. pratissolii females deprived of food emerging from A. kuehniella and C. cephalonica lived for 1.0 and 8.9 days when reared at 15°C e 33°C, respectively. The results indicate that eggs of A. kuehniella and C. cephalonica and temperatures from 21°C to 27°C were appropriate to rear T. pratissolii.