Estudio del índice de desarrollo del Trichogramma fasciatum (Perkins) Hymenoptera, Trichogrammatidae criado en huevos de Corcyra cephalonica (Stainton) Lepidóptera, Galleriinae, en función del tiempo de refrigerado.

Abstract

A study of the birth rate of Trichogramma fasciatum (Perkins), bred with eggs of Corcyra cephalonica (Stainton), showed that this dimishes significantly only from the second week of refrigeration on, thus making it possible to keep Trichogramma in refrigeration for one week without a reduction in its developmental index. A negative correlation between the duration of refrigeration time and the number of Trichogramma born was demonstrated. The equation of retrogression was established permitting calculation of the birth rate according to the number of days in refrigeration. Study of the superparasitism of Trichogramma fasciatum (Perkins) on Corcyra cephalonica (Stainton) eggs showed that double and triple cases develop in an inverted ratio in relation to refrigeration time. The proportion of Trichogramma fasciatum corresponding to each sex was determined in a population of more than 2 400 specimens. Females represented 60 percent of the total, while the proportion of each sex was constant independently of the duration of refrigeration time.