Acute Toxicity of Permethrin, Deltamethrin, and Etofenprox to the Alfalfa Leafcutting Bee

Abstract

Current regulatory requirements for insecticide toxicity to nontarget insects focus on the honey bee, Apis mellifera (L.; Hymenoptera: Apidae), but this species cannot represent all insect pollinator species in terms of response to insecticides. Therefore, we characterized the toxicity of pyrethroid insecticides used for adult mosquito management (permethrin, deltamethrin, and etofenprox) on a nontarget insect, the adult alfalfa leafcutting bee, Megachile rotundata (F.; Hymenoptera: Megachilidae) in two separate studies. In the first study, the doses causing 50 and 90% mortality (LD50 and LD90, respectively) were used as endpoints and 2-d-old adult females were exposed to eight concentrations ranging from 0.0075 to 0.076 μg/bee for permethrin and etofenprox, and 0.0013-0.0075 μg/bee for deltamethrin. For the second study, respiration rates of female M. rotundata were also recorded for 2 h after bees were dosed at the LD50 values to give an indication of stress response. Results indicated a relatively similar LD50 for permethrin and etofenprox, 0.057 and 0.051 μg/bee, respectively, and a more toxic response, 0.0016 μg/bee for deltamethrin. Comparatively, female A. mellifera workers have a LD50 value of 0.024 μg/bee for permethrin and 0.015 μg/bee for etofenprox indicating that female M. rotundata are less susceptible to topical doses of these insecticides, except for deltamethrin, where both A. mellifera and M. rotundata have an identical LD50 of 0.0016 μg/bee. Respiration rates comparing each active ingredient to control groups, as well as rates between each active ingredient, were statistically different (P < 0.0001). The addition of these results to existing information on A. mellifera may provide more insights on how other economically beneficial and nontarget bees respond to pyrethroids.

Pesticides Used on Beef Cattle Feed Yards Are Aerially Transported into the Environment Via Particulate Matter

“…In total, 32.4% of all PM samples collected near feed yards contained both permethrin and bifenthrin, indicating potential for additive toxicity. Additionally, 76% of all PM samples collected in this study contain pyrethroid concentrations higher than the honeybee contact LD 50 concentrations, , raising concern that PM emanating from feed yards may be toxic to nontarget invertebrates.…”

Residuos de plaguicidas en miel y cera de colonias de abejas de La Comarca Lagunera

“…Datos similares son reportados por Johnson et al (2010), con valores de 0.133 mg kg -1 . No obstante, este insecticida es altamente tóxico para las abejas, con una DL50 tópica de 0.024 µg/abeja (Piccolomini et al, 2018). La exposición prolongada de los piretroides pueden afectar la inmunidad celular y humoral; así como la disminución en la inmunidad en las abejas (Qi et al, 2019).…”

Tomate de cáscara (Physalis ixocarpa Brot. Ex Hornem.): prácticas sociotécnicas e indicadores agroecológicos en Vicente Guerrero, Tlaxcala.

“…However, periodic monitoring is recommended to obtain a more accurate approximation, given that tomatoes require this type of insect for pollination. It is important to note that the type of insecticides used, such as broad-spectrum pyrethroids, have toxic effects on pollinators, mainly bees (Piccolomini et al, 2018). Nevertheless, it is noteworthy that Grupo Vicente Guerrero has promoted agroecological practices, which have led to a reduction of up to 80 % in agrochemicals in grain crops such as beans, corn, and fava beans (Carrillo and Ramírez, 2017).…”