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Effects of residues of deltamethrin in cattle faeces on the development and survival of three species of dungbreeding insect
Author(s) -
WARDHAUGH KG,
LONGSTAFF BC,
LACEY MJ
Publication year - 1998
Publication title -
australian veterinary journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.382
H-Index - 59
eISSN - 1751-0813
pISSN - 0005-0423
DOI - 10.1111/j.1751-0813.1998.tb10159.x
Subject(s) - deltamethrin , biology , feces , larva , population , bioassay , fecundity , zoology , dung beetle , insect , toxicology , juvenile , scarabaeidae , pesticide , ecology , demography , sociology
Objective To assess the toxicity to insects of drug residues excreted in cattle faeces following treatment with deltamethrin. Design Bioassays were performed on one species of dung‐breeding fly ( Musca vetustissima ) and two species of dung beetle ( Onthophagus binodis and Euoniticellus fulvus ). Animals Cattle on properties near Kangaroo Valley, Canberra and Gundagai were treated with pour‐on formulations of deltamethrin. Untreated animals acted as controls. Procedures Faeces from treated and untreated cattle were inoculated with newly emerged fly larvae or fed to adults of two species of dung beetle. Percentage survival and duration of development provided measures of the toxicity of deltamethrin residues in faeces. Results Residues of deltamethrin were excreted in concentrations sufficient to inhibit survival of larvae of M vetustissima for 1 to 2 weeks after treatment. Peak concentrations of 0.4mg deltamethrin/kg dry weight of faeces occurred 3 days after treatment and were sufficient to kill adult beetles for at least twice this period. With one of two formulations tested, there was evidence of a reduction in dung beetle fecundity and an increase in the duration of juvenile development. A model of the effect of deltamethrin on the breeding success of dung beetles in the field suggests that a single treatment, applied when most of the population is in a non‐parous condition, may cause up to 75% reduction in beetle acitivity by the end of the season. Multiple treatments at 10 or 21 day intervals may drive local populations towards extinction. Conclusion Depending on the time and frequency of treatment, the effect of deltamethrin on insects in cattle faeces may range from negligible to catastrophic.