Fate of spinosad in litter and soils of a mixed conifer stand in the Acadian forest region of New Brunswick.
Spinosad is a natural insecticide, produced via fermentation culture of the actinomycete Saccharopolyspora spinosa, with potential use against a number of forest pests including spruce budworm (Choristoneura fumiferana [Clem]). Persistence of spinosad was determined in terrestrial fate experiments conducted within a semimature stand of black spruce (Picea mariana [Mill.]) and balsam fir (Abies balsamea [L]) in the Acadian forest region of New Brunswick, Canada. Results of experiments established under full coniferous canopy and in a canopy opening indicated that spinosad dissipated rapidly following hyperbolic kinetics in both litter and soils and was not susceptible to leaching. Time to 50% dissipation estimates for spinosyn A ranged from 2.0 to 12.4 days depending upon matrix and experimental conditions. Spinosyn D dissipated to levels below quantitation limits (0.02 microg/g of dry mass) within 7 days in all cases. Sporadic low-level detection of the demethylated metabolites suggested that parent compounds were degraded in situ.
Thompson
Dean G
DG
Canadian Forest Service, Great Lakes Forestry Centre, 1219 Queen Street East, Sault Ste. Marie, Ontario, Canada. dthompso@nrcan.gc.ca
Harris
Brenda J
BJ
Lanteigne
Leonard J
LJ
Buscarini
Teresa M
TM
Chartrand
Derek T
DT
D000900:Anti-Bacterial Agents / Q000032:analysis; D004338:Drug Combinations; D007306:Insecticides / Q000032:analysis; D007700:Kinetics; D018942:Macrolides / Q000032:analysis*; D009509:New Brunswick; D012044:Regression Analysis; D012987:Soil / Q000032:analysis*; D014197:Trees
D000900:Anti-Bacterial Agents; D004338:Drug Combinations; D007306:Insecticides; D018942:Macrolides; D012987:Soil; C114883:spinosyn A; C114884:spinosyn D; C415329:spinosad