Prevention of blowfly strike on coarse and fine woolled sheep with the insect growth regulator dicyclanil.
OBJECTIVE
To assess a ready-to-use formulation of dicyclanil to prevent blowfly strike on coarse and fine woolled sheep under New Zealand conditions.


METHODS
Randomized clinical field trials.


METHODS
In a first field trial, coarse wooled sheep treated with a ready-to-use, 5% dicyclanil formulation were compared with untreated control sheep for up to 21 weeks. In a second field trial, fine woolled sheep, treated with the same dicyclanil formulation, were compared with untreated sheep for up to 19 weeks. Efficacy was assessed by calculating the aggregated cumulative strike rate.


RESULTS
For trial 1 (coarse woolled sheep) the aggregated cumulative strike rate at the end of the trial at week 21 after treatment reached 3.9% and 19.1% for treated and untreated sheep, respectively. For the treated animals the aggregated cumulative strike rate reached the 1% and 2% benchmarks between weeks 11 and 12. For trial 2 (fine woolled sheep) the aggregated cumulative strike rate at the end of the trial at week 19 reached 0.6% and 7.5% for treated and untreated sheep, respectively. Wool length at the time of application did not substantially influence the efficacy of dicyclanil.


CONCLUSIONS
Under New Zealand field conditions, a ready-to-use 5% spray-on formulation of dicyclanil protected coarse woolled sheep for at least 12 weeks and fine woolled sheep for at least 19 weeks.
Nottingham
R M
RM
Novartis New Zealand Ltd, Private Bag 19-980, Avondale, Auckland, 1007, New Zealand.
Hosking
B C
BC
Schmid
H R
HR
Strehlau
G
G
Junquera
P
P
D000818:Animals; D004175:Diptera; D004478:Ectoparasitic Infestations / Q000517:prevention & control / Q000662:veterinary*; D007605:Juvenile Hormones / Q000008:administration & dosage*; D009520:New Zealand; D012756:Sheep; D012757:Sheep Diseases / Q000517:prevention & control*; D016896:Treatment Outcome; D014935:Wool
D007605:Juvenile Hormones; C121718:dicyclanil