Ac. Chukwudebe et al., TOXICITY OF EMAMECTIN BENZOATE TO MALLARD DUCK AND NORTHERN BOBWHITE QUAIL, Environmental toxicology and chemistry, 17(6), 1998, pp. 1118-1123
Nineteen-to 26-week-old mallard ducks (Anas platyrhynchos) were found
to be more sensitive than northern bobwhite quail (Colinus virginianus
) of the same age to single oral doses of emamectin benzoate. The resu
lting median lethal dose values determined for emamectin benzoate to m
allard duck and northern bobwhite quail were 76 and 264 mg/kg, respect
ively, and the no-observed-effect levels were <25 and 25 mg/kg, respec
tively. Exposure of 10-d-old mallard ducks and bobwhite quail to emame
ctin benzoate in feed also gave relatively high median lethal concentr
ation (LC50) values of 570 and 1,318 ppm, respectively, and no-observe
d-effect concentrations of 20 and <125 ppm, respectively. Clinical sig
ns of toxicity included lethargy, ruffled appearance, loss of righting
reflex, and reduction in food consumption; these signs appeared to be
fully reversible with cessation of exposure. The maximum residue leve
l of emamectin benzoate found in held-treated foliage is several-fold
(7,125-16,475) less than these LC50 values. Because the likely primary
route of emamectin benzoate exposure to birds is through treated food
in the diet, these results indicate minimal acute risk to avians from
emamectin benzoate use in crop protection.