The parasitism of Diatraea saccharalis (Fabr.) eggs by Trichogramma spp. is usually evaluated in sugar cane fields by employing artificial infestations of the host's egg masses. Thus, the number of eggs/mass and the parasitism of egg masses by Trichogramma spp. was quantified in order to provide a more realistic and accurate evaluation of the parasitism. Samples were taken in sugar cane fields (10 months old) showing a high degree of D. saccharalis infestation. Out of 634 egg-masses collected (7.621 eggs), 53 masses (785 eggs) showed no parasitism, whereas 581 (6.836 eggs) showed at least one egg parasitized. An analysis of all masses collected revealed an average of 11.8 ± 6.3 eggs/mass (mode of 9 eggs/mass and a range from 2 to 37), and 11±5.9 parasitized eggs (93.3% of parasitism, mode of 9 eggs/mass and range from 1 to 35). A high correlation between the number of eggs/mass and the number of parasitized eggs (r = 0.89) was observed.
Insecta; biological control; parasitoid; sugar-cane-borer; biology
