TY - JOUR
T1 - Insecticide residues in Australian plague locusts (Chortoicetes terminifera walker) after ultra-low volume aerial application of the organophosphorus insecticide fenitrothion
AU - Story, Paul G.
AU - Mineau, Pierre
AU - Mullié, Wim C.
PY - 2013/12
Y1 - 2013/12
N2 - The need for locust control throughout eastern Australia during spring 2010 provided an opportunity to quantify residues of the organophosphorus insecticide fenitrothion on nymphs of the Australian plague locust, Chortoicetes terminifera Walker. Residues were collected across the different physiological states-live, dead, and debilitated (characterized by ease of capture, erratic hopping, and the inability to remain upright)-of locust nymphs observed following exposure to fenitrothion. The time course of residue depletion for 72h after spraying was quantified, and residue-per-unit dose values in the present study were compared with previous research. Fenitrothion residue-per-unit dose values ranged from 0.2μg/g to 31.2μg/g (mean±standard error [SE]=6.3±1.3μg/g) in live C. terminifera nymps, from 0.5μg/g to 25.5μg/g (7.8±1.3μg/g) in debilitated nymphs, and from 2.3μg/g to 39.8μg/g (16.5±2.8μg/g) in dead nymphs. Residues of the oxidative derivative of fenitrothion, fenitrooxon, were generally below the limit of quantitation for the analysis (0.02μg/g), with 2 exceptions-1 live and 1 debilitated sample returned residues at the limit of quantitation. The results of the present study suggest that sampling of acridids for risk assessment should include mimicking predatory behavior and be over a longer time course (preferably 3-24h postspray) than sampling of vegetation (typically 1-2h postspray) and that current regulatory frameworks may underestimate the risk of pesticides applied for locust or grasshopper control.
AB - The need for locust control throughout eastern Australia during spring 2010 provided an opportunity to quantify residues of the organophosphorus insecticide fenitrothion on nymphs of the Australian plague locust, Chortoicetes terminifera Walker. Residues were collected across the different physiological states-live, dead, and debilitated (characterized by ease of capture, erratic hopping, and the inability to remain upright)-of locust nymphs observed following exposure to fenitrothion. The time course of residue depletion for 72h after spraying was quantified, and residue-per-unit dose values in the present study were compared with previous research. Fenitrothion residue-per-unit dose values ranged from 0.2μg/g to 31.2μg/g (mean±standard error [SE]=6.3±1.3μg/g) in live C. terminifera nymps, from 0.5μg/g to 25.5μg/g (7.8±1.3μg/g) in debilitated nymphs, and from 2.3μg/g to 39.8μg/g (16.5±2.8μg/g) in dead nymphs. Residues of the oxidative derivative of fenitrothion, fenitrooxon, were generally below the limit of quantitation for the analysis (0.02μg/g), with 2 exceptions-1 live and 1 debilitated sample returned residues at the limit of quantitation. The results of the present study suggest that sampling of acridids for risk assessment should include mimicking predatory behavior and be over a longer time course (preferably 3-24h postspray) than sampling of vegetation (typically 1-2h postspray) and that current regulatory frameworks may underestimate the risk of pesticides applied for locust or grasshopper control.
KW - Chortoicetes terminifera
KW - Fenitrothion
KW - Locust control
KW - Pesticide risk assessment
KW - Residue per unit dose
UR - http://www.scopus.com/inward/record.url?scp=84887824762&partnerID=8YFLogxK
U2 - 10.1002/etc.2366
DO - 10.1002/etc.2366
M3 - Article
C2 - 24038429
AN - SCOPUS:84887824762
SN - 0730-7268
VL - 32
SP - 2792
EP - 2799
JO - Environmental Toxicology and Chemistry
JF - Environmental Toxicology and Chemistry
IS - 12
ER -