Residual effect of synthetic insecticides on Trichogramma pretiosum Riley (Hym., Trichogrammatidae) in different generations - DOI: 10.4025/actasciagron.v30i2.1723

Abstract

This work aimed to evaluate the residual effects of the pesticides etofenprox, fenitrothion, methidathion and trichlorfon on adults of Trichogramma pretiosum, as well as on F₁ and F₂ generations of this parasitoid species, under laboratory conditions. Eggs of the factitious host Anagasta kuehniella (Zeller) (Lep., Pyralidae) were glued to blue paper cards, UV-killed and treated by dipping in the aqueous solutions of the pesticides and in distilled water (control) during five seconds. Then, the eggs were exposed to parasitization 1, 24 and 48 hours after the treatment, during a period of 24 hours. Afterwards, the eggs were maintained under controlled conditions at 24±1oC, RH of 70±10% and 12 hour-photophase, until the emergence of parasitoids. Etofenprox, fenitrothion and methidathion are toxic to T. pretiosum, whereas trichlorfon is selective and can be used together with this parasitoid species to control cotton pests