Indigenous and Exotic Trichogrammatids (Hymenoptera: Trichogrammatidae) Evaluated for Biological Control of Eoreuma loftini and Diatraea saccharalis (Lepidoptera: Pyralidae) Borers on Sugarcane

Investigations were conducted to determine relative suitability of eggs of sugarcane pests Eoreuma loftini (Dyar) and Diatraea saccharalis (F.) for parasitization by indigenous and exotic trichogrammatids. The eight species of trichogrammatids tested (three collected locally, the others from elsewhere) successfully developed on eggs of both hosts, with number of eggs parasitized per female ranging from 14.0 to 36.6 for E. loftini and from 0.1 to 21.5 on D. saccharalis. The most successful species on E. loftini and D. saccharalis were Trichogramma retorridum (Girault) and Trichogramma fuentesi Torre, respectively. In addition, exposure of E. loftini egg masses concealed in paper substrata or in dry leaf material demonstrated differences among parasite species in proportion of eggs attacked, ranging from 92.0% for T. retorridum to 18.0% for Trichogramma chilonis Ishii. Results indicate that although all eight species developed on E. loftini in the laboratory, the concealed location of E. loftini egg masses in the field may place limits on parasitization by trichogrammatids.