A study was carried out in the laboratory to investigate the side-effects reported in Brazil of eight glyphosate formulations (Roundup®, Roundup® WG, Roundup® Transorb, Polaris®, Gliz® 480 CS, Glifosato Nortox®, Glifosato 480 Agripec® and Zapp® Qi) on the egg parasitoid Trichogramma pretiosum (Hym., Trichogrammatidae). The experiments were carried out by exposing the adult parasitoids to fresh pesticide residues applied on glass plates at a concentration of 14.4 mg L-1 of acid equivalent of glyphosate. The control group was treated with distilled water. Eggs of the alternative host Anagasta kuehniella (Lep., Pyralidae) were offered to parasitism. The capacity of parasitism per T. pretiosum adult female and the reduction in capacity of parasitism compared with the control group were used to estimate toxicity of the product. The formulations were classified into four categories, according to parasitism reduction: 1, harmless (<30%); 2, slightly harmful (30-79%); 3, moderately harmful (80-99%); 4, harmful (>99%). The results showed that the side-effects of the glyphosate formulations were dependent on type of salt and that formulations with potassic salt (Zapp® Qi) and ammonium salt (Roundup® WG) were slightly harmful to T. pretiosum adults. The remaining formulations isopropylamine salt (Roundup®, Roundup Transorb®, Polaris®, Gliz® 480 SC, Glifosato Nortox®, Glifosato 480 Agripec®) were moderately harmful to T. pretiosum adults.
egg parasitoids; herbicide; biological control
