Toxicity of pesticides used in citrus crops to workers of Apis mellifera Linnaeus 1758 (Hymenoptera: Apidae). / Toxicidade de produtos fitossanitÃrios utilizados em citricultura a operÃrias de Apis mellifera Linnaeus, 1758 (Hymenoptera: Apidae)

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

The toxic effects of some pesticides registered for use in citrus crops, to workers of Apis mellifera Linnaeus, were evaluated in the laboratory. The experiments were carried out in a completely randomized design and the pesticides (commercial formulations) tested were: thiamethoxam (Actara 250WG), deltamethrin (Decis 25CE), lufenuron (Match CE), tebufenozide (Mimic 240SC), methidathion (Supracid 400CE) and abamectin (Vertimec 18CE). Four bioassays were carried out, corresponding to different forms of exposure of the insects to the pesticides: topical spraying, contaminated food (Candy paste) and contact with treated Petri dishes or citrus leaves. The rates of application of the pesticides were based on their highest recommended rates for citrus crops. The bees were collected from a single hive, being anesthetized with CO2 for two minutes for the handling and setting of the bioassays, which were carried out under temperature of 25Â2oC, RH of 70Â10% and 12-hour photophase. It was found that, regardless of the mode of application, both thiamethoxan and methidathion were highly toxic to the bees, causing 100% of mortality after about 22h of exposure, on average among the bioassays. Abamectin was extremely toxic, with a mean of 98% of mortality among the bioassays, after 48h of exposure. Deltamethrin was medially toxic to the bees, with a mean of 45% of mortality in the four bioassays at the end experiment. Propargite was toxic in the bioassay of contaminated Candy paste with a mean of 75% of mortality; in the other bioassays this compound was little toxic, causing less than 12% of mortality. Lufenuron, tebufenozide and cyhexatin did not present any deleterious effects on the adults of A. mellifera, being considered selective, with means of 8.3, 4.3 and 4.3% of mortality, respectively, among the bioassays.

ASSUNTO(S)

entomologia agricola citros honey bee abelhas selectivity citrus inseticidas acaricidas apis mellifera apis mellifera seletividade isecticides acaricides

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