Simulation of fly-waves to assess the ability of diflubenzuron to protect sheep against flystrike by Lucilia cuprina.
Sheep were exposed to mass-released gravid females of the sheep blowfly, Lucilia cuprina, in a fly-proof animal house at various times after treatment with the insecticide diflubenzuron (1000, 1500 and 2500 ppm a.i.). Untreated sheep were similarly exposed as controls, while sheep treated with either diazinon (400 ppm a.i.) or cyromazine (1000 ppm) were used as standards for comparison. Before exposure, groups of sheep were wetted by simulating rainfall in the animal house in order to increase their susceptibility to flystrike by L. cuprina. In one trial, sheep jetted with either diflubenzuron or cyromazine (both at 1000 ppm) were protected against flystrike for at least 110 days. At 1500 ppm, diflubenzuron performed significantly better with no bodystrike occurring in the group until the end of the trial at 170 days. Under more severe fly pressure in a second trial diflubenzuron at concentrations up to 2500 ppm provided the same protection as diazinon (approximately 56 days), but performed significantly better thereafter. No cross-resistance to diflubenzuron was found in diazinon-resistant field populations of L. cuprina in laboratory bioassays. The data show that diflubenzuron would be suitable as a prophylactic treatment for flystrike.
D000818:Animals; D003976:Diazinon / Q000627:therapeutic use; D004132:Diflubenzuron / Q000627:therapeutic use*; D004175:Diptera; D004478:Ectoparasitic Infestations / Q000517:prevention & control / Q000662:veterinary*; D005260:Female; D007305:Insecticide Resistance; D007306:Insecticides / Q000627:therapeutic use; D007605:Juvenile Hormones / Q000627:therapeutic use*; D011891:Rain; D011897:Random Allocation; D012756:Sheep; D012757:Sheep Diseases / Q000517:prevention & control*; D014227:Triazines / Q000627:therapeutic use
D007306:Insecticides; D007605:Juvenile Hormones; D014227:Triazines; C028704:cyromazine; D004132:Diflubenzuron; D003976:Diazinon