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Long‐lasting prevention against blowfly strike using the insect growth regulator dicyclanil
Author(s) -
BOWEN FL,
FISARA P,
JUNQUERA P,
KEEVERS DT,
MAHONEY RH,
SCHMID HR
Publication year - 1999
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.1751-0813.1999.tb12092.x
Subject(s) - wool , zoology , veterinary medicine , insect growth regulator , placebo , myiasis , field trial , medicine , toxicology , biology , insect , larva , ecology , agronomy , geography , alternative medicine , archaeology , pathology
Objective To assess a ready‐to‐use formulation of dicyclanil to prevent blowfly strike on Merino sheep under Australian conditions. Design Randomised clinical trials conducted in an environment house and in the field. Procedure Two environment house trials were used to measure the protection against flystrike provided by a jetting or a ready‐to‐use 5% spray‐on formulation of dicyclanil over 22 and 31 weeks respectively. Oviposition and strikes we re recorded weekly for each sheep. In two field trials the occurrence of strike in Merino sheep treated off‐shears or in long wool with dicyclanil or with cyromazine was compared for up to 38 weeks after treatment. Efficacy was assessed by calculating the cumulative percentage of sheep struck. Results Under environment house conditions, sheep jetted with dicyclanil at 1.50, 0.75 and 0.30 g per sheep developed 0, 8 and 9 strikes respectively during the 22 weeks of the trial, whereas there were 358 strikes present in the placebo group. Sheep sprayed with dicyclanil at 2.25, 1.50 and 0.75 g per sheep developed 5, 11 and 29 strikes respectively between weeks 15 and 31 after treatment, whereas there were 185 strikes present in the untreated controls. In field trials the cumulative percentage of sheep struck reached 1% between weeks 12 to 13 after sheep had been treated with cyromazine. Sheep treated with dicyclanil reached the 1% limit at week 21 after treatment. Conclusion Under Aus tralian field conditions, a ready‐to‐use 5% spray‐on formulation of dicyclanil applied off‐shears or to long wool protected Merino sheep from blowfly strike for a period of at least 20 weeks.