Efeito residual de Espinosinas sobre a sobrevivência e capacidade de voo de Apis mellifera (Hymenoptera: Apidae).

Abstract

The bee Apis mellifera (Hymenoptera: Apidae) is an essential pollinator for obtaining fruits in several agricultural crops, such as melon. However, the abusive use of pesticides has caused a decline in the population of pollinators in agricultural areas. Therefore, the objective of this work was to evaluate the effect of the insecticides Spinosad and Spinetoram on A. mellifera, through residual contact on melon leaves as a function of time after spraying. The work was carried out at the Entomology Laboratory of the Academic Unit of Agricultural Sciences, belonging to the Center for Agro-Food Sciences and Technology of the Federal University of Campina Grande, Pombal – PB. To carry out the work, adult workers of A. mellifera from colonies belonging to the apiary located in the institution were used. The bioassay was carried out in a completely randomized design, in a 6 X 3 factorial scheme, with two doses of the insecticide Spinosad (0.144 g i.a./L and 0.192 g i.a./L), two doses of the insecticide Spinetoram (0.06 g i.a./L and 0.08 g i.a./L), an absolute control (distilled water), a positive control (Thiamethoxam) at the maximum recommended dose for pest control in melon (0.30 g i.a./L) and three exposure times (1, 2 and 3 hours) after applying the treatments, with 10 replications, each experimental unit consisting of 10 adult bees. Regardless of the dose and time of exposure after spraying, the insecticides Spinetoram and Spinosad were harmful to A. mellifera, differing significantly from the absolute control and causing mortality between 61.1 and 100% in the application of Spinetoram and between 74 and 97.1% in relation to Spinosad. The median lethal time (TL50 – hours) provided by the insecticides Spinetoram and Spinosad, regardless of dose and exposure time after spraying, was much lower than that observed in bees exposed to absolute control. The LT50 provided by the evaluated Spinosyns varied between 9.2 and 38.1 hours. It was observed that 100% of the bees were unable to fly after exposure to Spinetoram treatments at a dose of 0.06 g i.a./L and at times 1, 2 and 3 h after spraying, Spinetoram at a dose of 0.08 g i.a./L at 2 and 3 h after spraying, Spinosad at a dose of 0.144 g i.a./L at the three exposure times and Spinosad at a dose of 0.192 g i.a./L at a time of 1 h after spraying. Only when Espionosade was applied at a dose of 0.192 g i.a./L and 2 and 3 h after spraying, bees

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were able to fly or walk. Regardless of the evaluated dose and the time of exposure of the bees after spraying the melon leaves, the insecticides Spinetoram and Spinosad were harmful to A. mellifera and impaired the flight capacity of the bees.