Efficacy of zeta-cypermethrin as pour-on or spray formulations for the control of buffalo fly (Haematobia irritans exigua) in cattle.
OBJECTIVE
To determine the efficacy of zeta-cypermethrin in controlling buffalo fly (Haematobia irritans exigua).


METHODS
Five field trials in northern and central Queensland.


METHODS
Zeta-cypermethrin pour-on at 2.5 mg/kg, spray at 62.5 ppm, deltamethrin pour-on and pour-on vehicle were applied to groups of 20 cattle. Buffalo fly counts were conducted three times before treatment and 3, 7, 14, 21, 28 and 35 days after treatment.


RESULTS
In central Queensland where synthetic pyrethroid resistance in buffalo fly populations was rare, 2.5 mg/kg of zeta-cypermethrin pour-on gave good control of buffalo fly for 4 weeks and was better than a deltamethrin product. A zeta-cypermethrin spray used at 62.5 ppm gave 14 days control. In far-north Queensland where resistance to synthetic pyrethroids and heavy rain was common, the maximum period of efficacy of zeta-cypermethrin pour-on was reduced to 2 weeks.


CONCLUSIONS
In areas where there is low resistance to synthetic pyrethroids among buffalo flies, zeta-cypermethrin pour-on can be expected to give good control for 4 weeks.
Rothwell
J T
JT
Elanco Animal Health, West Ryde, New South Wales.
Hacket
K C
KC
Friend
M
M
Farnsworth
W R
WR
Lowe
L B
LB
D000287:Administration, Topical; D000336:Aerosols; D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000517:prevention & control*; D004478:Ectoparasitic Infestations / Q000517:prevention & control / Q000662:veterinary*; D004655:Emulsions; D005260:Female; D007305:Insecticide Resistance; D007306:Insecticides / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male; D009117:Muscidae; D011722:Pyrethrins / Q000008:administration & dosage / Q000627:therapeutic use*; D011793:Queensland; D011891:Rain
D000336:Aerosols; D004655:Emulsions; D007306:Insecticides; D011722:Pyrethrins; C017160:cypermethrin