Artigo
Biopesticide‐induced behavioral and morphological alterations in the stingless bee Melipona quadrifasciata
Autor
Barbosa, Wagner F.
Tomé, Hudson Vaner V.
Bernardes, Rodrigo C.
Siqueira, Maria Augusta L.
Smagghe, Guy
Guedes, Raul Narciso C.
Institución
Resumen
Because of their natural origin, biopesticides are assumed to be less harmful to beneficial insects, including bees, and therefore
their use has been widely encouraged for crop protection. There is little evidence, however, to support this ingrained notion of
biopesticide safety to pollinators. Because larval exposure is still largely unexplored in ecotoxicology and risk assessment on bees, an
investigation was performed on the lethal and sublethal effects of a diet treated with 2 bioinsecticides, azadirachtin and spinosad, on the
stingless bee, Melipona quadrifasciata, which is one of the most important pollinators in the Neotropics. Survival of stingless bee larvae
was significantly compromised at doses above 210 ng a.i./bee for azadirachtin and 114 ng a.i./bee for spinosad. No sublethal effect was
observed on larvae developmental time, but doses of both compounds negatively affected pupal body mass. Azadirachtin produced
deformed pupae and adults as a result of its insect growth regulator properties, but spinosad was more harmful and produced greater
numbers of deformed individuals. Only spinosad compromised walking activity of the adult workers at doses as low as 2.29 ng a.i./bee,
which is 1/5000 of the maximum field recommended rate. In conclusion, the results demonstrated that bioinsecticides can pose significant
risks to native pollinators with lethal and sublethal effects; future investigations are needed on the likelihood of such effects under field
conditions.