SANTOS, Poliana Linhares dos.
Résumé:
The honey bee Apis mellifera (Hymenoptera:Apidae) is essential in citrus growing areas, one
of the biggest challenges for producers is to combine chemical pest control with the
conservation of bees in the field. Therefore, the objective was to evaluate the residual toxicity
of Abamectin as a function of time after spraying on A. mellifera. The experiment was carried
out at the Entomology Laboratory belonging to CCTA/UFCG, Pombal/PB, in a completely
randomized design, in a 3 /L, one control (distilled water) and five exposure times (1, 2, 3, 24
and 48 hours after spraying), with five replications, with each experimental unit consisting of
10 adult bees. After exposure to insecticide residues, mortality and motor disorders (prostration,
tremors, paralysis, reduction in feeding) of bees were evaluated at 1, 2, 3, 4, 5, 6, 12 and 24
hours. After 24 hours, the flying capacity of the surviving bees was assessed. Abamectin at the
minimum and maximum doses respectively, caused around 26% and 34% of mortality after 1
hour of spraying, 16% and 18% after 2 hours of spraying, 22% and 32%, when after 3 hours of
spraying, 28% and 34% after 24 hours and 40% and 48%, when exposed to residues on the
leaves 48 hours after spraying. It was observed that the insecticide abamectin, regardless of
dose and time after spraying, provided a median lethal time TL50 of 29.37 hours and the control
provided a TL50 of 2,059.05 hours. It was observed that around 50% of the control bees were
able to fly to a height of 91 cm or to the top of the tower, and for the different treatments with
Abamectin, it was observed that the bees reached varying levels of height, due to their behaviors
of paralysis and food reduction. Abamectin proved to be moderately toxic when in residual
contact regardless of the doses and exposure interval, however, there was a reduction in the
flying capacity of the surviving bees after the period of exposure to the insecticide.
