Boletín de la AeE

Olfactometer experiments were conducted to study the responso of an aphid parasitoid. Aphelimis asychis (Walker) to the sorghum plant infested with greenbug. Schfcaphis gramimum (Rondan!) and malathion-treated plan, at a tritrophic level. Parasitoids were signifícantly attracted to the greenbug-infested sorghum leaf and damaged sorghum leaf (greenbug-remover) (P<0.05). Significant differences were however not seen when only greenbugs were used. suggesting thal the plant plays an important role in parasitoid host ílnding. The results also showed a positive response to malathion-treated plant may be due to the increased attractiveness of the plant caused by the insecticide damage.

Furthermore, parasitoids exposed to sublethal doses, did not exhibit any movement. The results indicated that insecticide applications may affect plants hich in turn become increasmgly attractive to some beneficiáis resulting in their death or arrestment at sublethal doses.