title: Effects of the mosquito larvicide GB-1111 on bird eggs.
abstract: Golden Bear Oil (GB-1111; legal trade name for GB-1313) is a petroleum distillate used in the United States and other countries as a mosquito larvicide. As part of an evaluation of the potential effects of GB-1111 on birds, fertile eggs of mallards (Anas platyrhynchos) and bobwhite (Colinus virginianus) were incubated in the laboratory, and treated on day 4 of incubation with external applications equivalent to either 0, 1/3, 1, 3 or 10 times the maximum rate (X) of 47 l/ha (5 gal/A) of field application of GB-1111. Hatching success was significantly reduced in mallards treated at 3 and 10 times the maximum field application, with a calculated approximate LD50 of 1.9 times the maximum field application. Most mortality occurred within a week of treatment. Hepatic P450-associated monooxygenase activity (ethoxyresorufin-O-dealkylase; EROD) was negatively related to dose. In the 3X group there was a significant increase in the concentration of hepatic reduced glutathione (GSH) but a decrease in protein-bound thiols (PBSH). Hatching success of bobwhite was marginally reduced at the highest level of treatment (10X). Other effects at this level in bobwhite included a significant increase in incidence of abnormal embryos or hatchlings, lower body and liver weights, and a two-fold increase in hepatic microsomal EROD activity in hatchlings. The recommended maximum rate of field application of GB-1111 is unlikely to impair the survival or development of bobwhite embryos but is potentially toxic to mallard embryos under conditions of larvicide drift or spray overlap.
authors.affiliation: USGS Patuxent Wildife Research Center, 12011 Beech Forest Road, Laurel, MD 20708-4041, USA. david_hoffman@usgs.gov
authors.forename: D J
authors.initials: DJ
authors.lastname: Hoffman
authors.forename: P H
authors.initials: PH
authors.lastname: Albers
authors.forename: M J
authors.initials: MJ
authors.lastname: Melancon
authors.forename: A K
authors.initials: AK
authors.lastname: Miles
mesh_terms: D000014:Abnormalities, Drug-Induced / Q000209:etiology / Q000662:veterinary*; D000818:Animals; D002140:California; D004372:Ducks; D004781:Environmental Exposure; D007306:Insecticides / Q000506:poisoning / Q000633:toxicity*; D007928:Lethal Dose 50; D008899:Mineral Oil / Q000506:poisoning / Q000633:toxicity*; D009032:Mosquito Control; D013045:Species Specificity
chemical_list: C478368:GB-1111; D007306:Insecticides; D008899:Mineral Oil