Open AccessThe effects of spinosad insecticide to adults of Apis mellifera, Megachile rotundata and Nomia melanderi (Hymenoptera: Apidae)
Author(s) -
D. F. Mayer,
Gabriella Kovács,
B. L. Brett,
B. Bisabri
Publication year - 2001
Publication title -
international journal of horticultural science
Language(s) - English
Resource type - Journals
eISSN - 2676-931X
pISSN - 1585-0404
DOI - 10.31421/ijhs/7/1/257
Subject(s) - spinosad , honey bee , apidae , biology , toxicology , apoidea , aculeata , botany , horticulture , hymenoptera , agronomy , pesticide
The toxicity of spinosad to adult female bees tended to be least to the honey bee (Apis mellifera L.) (LD50 = 0.078 pg/bee), intermediate to the alkali bee (Nomia melanderi) (0.065 pg/bee), and greatest to the alfalfa leafcutter bee (Megachile rotundata (F.)) (0.058 pg/bee), both in topical drop tests and in tests involving spinosad residues on alfalfa (Medicago sativa) foliage. For the calculated LD50 pg/g, the honey bee (LD50 = 0.612 pg/g) was the most susceptible followed by the alkali bee (0.773 pg/g) and the leafcutter bee (1.908 pg/g). The honey bee oral LD50 was 0.063 pg/bee and the calculated LD50 0.492 pg/g. Adding an adjuvant to spinosad sprays did not change the toxicity of spinosad to bees in residue bioassay studies. Spinosad at as high as 500 ppm in feeders containing a sucrose/honey syrup caused no significant reduction in honey bee visitation or total syrup consumed.