Controle de Brevipalpus phoenicis (Geijskes, 1939) E Oligonychus ilicis (McGregor, 1917) (Acari: Tenuipalpidae, Tetranychidae) em cafeeiro e o impacto sobre ácaros benéficos: I - abamectin e emamectin

Abstract

The mite Brevipalpus phoenicis (Geijskes, 1939) (Acari: Tenuipalpidae) is important for coffee plants (Coffea spp.) for being the vector of the coffee ringspot virus, which is responsible for leaf fall and bad quality of the coffee beverage. The red spider mite, Oligonychus ilicis (McGregor, 1917) (Acari: Tetranychidae) is also important, for reducing the areas of photosynthesis in leaves. Some mites of the family Phytoseiidae are efficient predators associated to the pest-mites. This work had as objective to study the control of the pest-mites and the impact of the abamectin and emamectin on phytoseiids. Studies were carried out in laboratory to investigate the ovicidal, topical, residual, topical plus residual effects of the products on the pest-mites and the physiologic selectivity to the phytoseiids. The persistence of the products in the control of pest-mite was studied in semi-field conditions. The ovicidal effect was evaluated in eggs in the beginning and end of incubation; the residual, topical and topical plus residual effects on larvae, nymphs and adults were assessed through mortality evaluation 48 h after spraying, while the persistence was evaluated until 30 days after spraying. The phytoseiids selectivity was evaluated by the total effect in adult females, in residual test in glass surface. The results showed that abamectin and emamectin do not possess ovicidal action, in both pest-mite species studied. Considering the topical plus residual effect, the abamectin and emamectin was highly efficient in the control of larvae, nymphs and adults of the B. phoenicis; only the abamectin was efficient for O. ilicis control. Abamectin was slightly and moderately noxious and emamectin was shown to be innocuous and slightly noxious to the phytoseiids. Due to efficiency presented in the pest-mites control, and selectivity to the phytoseiids, it is concluded that abamectin and emamectin can be used in integrated pest management programs of B. phoenicis, and abamectin for the management of B. phoenicis and O. ilicis in coffee trees.