XVI International Botanical Congess

We studied the interaction between the honeydew-producing whitefly Aleurothrixus aepim and tending ants on Croton in SE Brazil. After 75 days, adult whiteflies emerged in greater numbers from ant-tended than from ant-excluded nymph aggregations, the latter being heavily attacked by fungi due to accumulation of honeydew. Aggregations with low levels of ant attendance produced fewer adults than those with higher levels. Parasitoid wasps were more frequently seen on ant-excluded than on control aggregations. Predators were equally frequent in either group. This is the first experimental demonstration of ant protection to whiteflies. Since aleyrodid honeydew causes considerable damage to several crop plants, the results suggest that honeydew-gathering by tending ants can be relevant in the management of agroecosystems.