BIOLOGY AND PARASITISM OF TRICHOGRAMMA-PRETIOSUM RILEY (HYM, TRICHOGRAMMATIDAE) ON EPHESTIA-KUEHNIELLA (ZELLER) (LEP, PYRALIDAE) AND HELIOTHIS-ZEA (BODDIE) (LEP, NOCTUIDAE) EGGS

Biological aspects of Trichogramma pretiosum Riley, 1879, reared on ar tificial host Ephestia kuehniella (Zeller, 1879), were studied in incu bators at 25-degrees-C (+/- 1-degree-C); 60% (+/- 10%) RH and 14 h pho tophase with the aim of obtaining basic information for the biological control of Heliothis zea (Boddie, 1850) in corn crop. The average dur ation of the life cycle (egg-adult) of T. pretiosum was similar when r eared on natural and factitious host. Sexual ratio of the parasitoid w as not affected by the natural or factitious host. The longevity of T. pretiosum was higher when reared on factitious host relating to natur al host. The parasitism capacity of the two strains of T. pretiosum on E. kuehniella eggs was similar, with a high rate of parasitism in the first four days of the female's life.