Insecticide residues in Australian plague locusts (Chortoicetes terminifera Walker) after ultra-low volume aerial application of the organophosphorus insecticide fenitrothion.

Abstract

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 72 h 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 0.2 µg/g to 31.2 µg/g (mean ± standard error [SE] = 6.3 ± 1.3 µg/g) in live C. terminifera nymps, from 0.5 µg/g to 25.5 µg/g (7.8 ± 1.3 µg/g) in debilitated nymphs, and from 2.3 µg/g to 39.8 µg/g (16.5 ± 2.8 µg/g) in dead nymphs. Residues of the oxidative derivative of fenitrothion, fenitrooxon, were generally below the limit of quantitation for the analysis (0.02 µg/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 3-24 h postspray) than sampling of vegetation (typically 1-2 h postspray) and that current regulatory frameworks may underestimate the risk of pesticides applied for locust or grasshopper control.

• Authors: Paul G Story, Pierre Mineau, Wim C Mullié
• Journal: Environmental toxicology and chemistry (Environ Toxicol Chem) Vol. 32 Issue 12 Pg. 2792-9 (Dec 2013) ISSN: 1552-8618 [Electronic] United States
• PMID: 24038429 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2013 SETAC.

Chemical References

• Environmental Pollutants
• Insecticides
• Pesticide Residues
• fenitrooxone
• Fenitrothion

Topics

• Animals
• Australia
• Environmental Pollutants (metabolism, toxicity)
• Fenitrothion (analogs & derivatives, metabolism, toxicity)
• Grasshoppers (metabolism)
• Insecticides (metabolism, toxicity)
• Nymph (drug effects, metabolism)
• Pest Control
• Pesticide Residues (metabolism, toxicity)
• Seasons