Seletivity of lambda-cyhalothrin to Trichogramma pretiosum Riley, 1879 (Hymenoptera: Trichogrammatidae) - DOI: 10.4025/actasciagron.v27i2.1852

Abstract

Trichogramma pretiosum Riley, 1879 is among the most widely used natural enemies to the control of pests in Brazil, thus its preservation on the agroecossystems through selectivity pesticids is fundamental. The selectivity of lambda-cyhalothrin, in two formulations, 50 CS and 250 CS, to T. pretiosum was evaluated the maternal generation and F₁ offspring. Eggs of Anagasta kuehniella (Zeller), were given immediately (1 hours), 24 and 48 hours after immersion in the chemical solutions, and eggs treated 0-24, 72-96 and 168-192 hours after parasitism. Lambda-cyhalothrin on the formulation 50 CS and 250 CS, was harmful to T. pretiosum when applied before the contact of the females with the host eggs. The formulation 250 CS was more harmful than the formulation 50 CS, affecting the parasitism capacity, longevity of the females, and survival of the F₁ offspring, when applied before and after parasitism. The reduction of the parasitism capacity on eggs of A. kuehniella before immersion in the chemical solutions was 27.39% and 53.12% to the formulation 50 CSA and 250 CS, respectively.