Susceptibility of the poultry red mite, Dermanyssus gallinae (Acari: Dermanyssidae) isolated from the layer farms to some acaricides

Poultry red mite, Dermanyssus gallinae, is an important ectoparasite in poultry and has impacts on egg and meat production worldwide. Susceptibility of the populations of the red mite to amitraz (Mactomile®), carbaryl (Mac tak®) and cypermethrin (Sevin®) were evaluated gathered from eight naturally infected caged laying poultry farms, which are located in North West of Iran. Twenty mites from all stages were exposed to five concentrations of the acaricides and distillated water was used as control. The test was repeated five times for each concentration of the acaricides. The mites were confined in the test cells at 20°C and humidity of 60% for 24 hours. The mean efficacy of cypermethrin (100 ppm), amitraz (200 ppm) and carbaryl (850 ppm) were 36.38%, 67.68% and 70.77% respectively. The difference of mean efficacy of cypermethrin was significant (P ≤0.05) by amitraz and carbaryl, but the difference between amitraz and carbaryl was not significant (P ≥0.05). The lowest efficacy (11.5%) for cypermethrin and the highest (100%) for carbaryl had been record.
The results showed that the field red mite populations from commercial layer farms in North West of Iran are tolerant to tested acaricides. The poor efficacy of commercially used acaricides that is supported by extensive frequency of red mite in layer farms indicates the need for replacing the old pesticides with more effective pesticides and to set up a better monitoring system for acaricides usage.