The selectivity of 24 herbicides registered on corn to Trichogramma pretiosum (Hymenoptera: Trichogrammatidae) was assessed under laboratory conditions (25 ± 1 ºC temperature, 70 ± 10% relative humidity, 14 4 photophase and brightness 500 lux). The adult parasitoids were submitted to a dry film of the herbicides applied on glass plates and the parasitism capacity of the females was evaluated. Reduced parasitism capacity in the treatments was compared with the negative control (distilled water) and used to classify the herbicides into four categories: 1, harmless (< 30%); 2, slightly harmful (30-79%); 3, moderately harmful (80-99%) and 4, harmful (> 99%). The herbicides Callisto, Equip Plus, Extrazin SC, Primóleo, Provence 750 WG and Siptran 500 SC were found to be harmless (class 1); Agrisato 480 SL, Gesaprim GrDA, Glifos, Glyphosate Nortox, Gliz 480 SL, Polaris, Primatop SC, Sanson 40 SC, Trop and Zapp Qi , slightly harmful (class 2); Finale, Herbadox, Poast, Roundup Original, Roundup Transorb and Roundup WG, moderately harmful (class 3); Gramoxone 200 and Primestra Gold were found to be harmful (class 4) to the adults of T. pretiosum at the dosages used. The harmful herbicides (class 2, 3 and 4) must undergo the next test stages, involving tests at the immature phases of the parasitoid under laboratory conditions and adult parasitoids under field conditions.
chemical control; side effects; natural enemy; egg parasitoid; Zea mays
