Toxicidade de duas formulações comerciais de neonicotinoides para as abelhas nativas sem ferrão Trigona aff fuscipennis Friese 1900 e Scaptotrigona aff depilis Moure 1942 (Hymenoptera: Apidae)

• Autor(a) principal: Monteiro, Victor Magalhães
• Data de Publicação: 2021
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Ceará (UFC)
• Texto Completo: http://www.repositorio.ufc.br/handle/riufc/73624
• topic: Meliponíneos; Pesticida; Avaliação de risco; Seletividade; Teste de toxicidade

Pesticides, particularly the systemic ones, which include the neonicotinoids, are considered one of the causes of the decline of the wildlife population in general, including managed and wild bees. The risk assessment of those molecules in bees is in accordance with international standards, which are based on the effect of the active ingredient of the pesticide in different concentrations on the reference species Apis mellifera. However, there are some issues concerning this approach. Thus, the present study aimed to investigate the toxicity of commercial formulations of two neonicotinoids (thiamethoxam and thiacloprid) in two species of stingless bees: Trigona aff fuscipennis and Scaptotrigona aff depilis. For this purpose, were adapted from the protocols of the OECD (Organization for Economic Co-operation and Development) toxicity test with bees, topical and oral mortality test. For the commercial formulation with thiamethoxam, the results with T.fuscipennis were 0.08131 and 0.08443 for topical (24h and 48h, respectively), and 0.00029 to oral (24 h); as for S. depilis, there were results of 0.06539 and 0.04474ƞg/µl topical (24h and 48h, respectively), also 2.30472 and 1.18265ƞg/µl oral (24h and 48h, respectively). Regarding the commercial formulation with thiacloprid, there were results of 0.1578 and 0.11697ƞg/µl LD50 (24h and 48h, respectively), 5.35627 and 2.8739ƞg/µl oral (24h and 48h, respectively), with T.fuscipennis; also 2.06348 and 0.00187ƞg/µl topical (24h and 48h, respectively) and 0.00489 e 0.00123ƞg/µl oral (24h e 48h, respectively) for S. depilis. Therefore, this study concludes that the T.fuscipennis and the S. depilis stingless bees are much more sensitive to the commercial formulation of the thiamethoxam and thiacloprid pesticides than the reference species; that Apis mellifera is not a good reference species for the assessment of the safety of the toxic action of pesticides in bees; that the use of a sole species as general reference may not assess the toxic risks properly; and that there is the need to take the commercial formulations into consideration in risk assessments for bees.