194 



randomly throughout their cages and did not necessarily remain in contact 

 with the treated surface. No further contact with the panels was needed 

 to cause the flies to die. 



At 100 days post-treatment, the poultryman fogged one end of his 

 poultry house while a fly trial was in progress and the mortality rates 

 of two control panels were affected (Table 53). 



When a trial was performed 116 days post-treatment, ambient tempera- 

 ture was 29.4 C, but temperatures inside the poultry houses were above 

 35.0 C. High control mortality during this trial was attributed to the 

 heat. 



When an additional trial was attempted ca . 325 days post-treatment, 

 a new flock of chickens had been housed on the farm. In between flocks, 

 houses and panels had been thoroughly sprayed with a disinfectant and 

 when flies were exposed to the panels, mortality was zero in all cases. 



Northern Fowl Mites 

 Dosage-Mortality Curves for Selected Acaricides 



Compounds tested were four synthetic pyrethroids [SBP-1382 (Penick 

 2k. 3% EC), BW 21Z (Burroughs Wellcome 42.5% EC), SD 43775 (Shell 10% WDL) , 

 and Ectiban (ICI Americas 26.0% EC)], Sevin (Union Carbide 99-9% crysta- 

 line powder), and malathion (American Cyanamid 96.4% EC). 



Resul ts. The test concentrations of acaricides and the total, per 

 cent, and corrected per cent mite mortality for each concentration tested 

 are shown in Table 54. Figure 40 shows all six dosage-mortality curves 

 plotted on one set of axes and the regression equations and LC 50 's are 

 shown in Table 55. Probabilities, probits, log doses, and upper and 

 lower fiducial limits are shown in Appendices 4 through 9- 



