Control of Poultry Mites (Dermanyssus)*

Arthropods are one of the most concerning threats in poultry industries due to both direct and indirect pathogenic effects. One of the most important arthropods affecting poultry production is in the genus Dermanyssus (Acari: Dermanyssidae) with Dermanyssus gallinae (De Geer) the most important (Fletcher and Axtell 1991; Maurer and Baumga rtner 1992). Dermanyssus gallinae, also known as 'poultry red mite' or 'red mite' is a direct pest becauseitisanobligatoryblood-suckingparasite;itisonthebirdonlytofeedfor30-60 min and to spend the rest of the time concealed in cracks and crevices or in the litter. Its eggs are laid in the hiding places and hatch into six-legged larvae in 2-3 days. The chicken mite is seldom seen on the birds because of its intermittent feeding at night but skin lesions (especially on the breast and lower legs) are evidence of the feeding (Baker 1999). InEurope,D.gallinaeisoneofthemajorproblemsinlayingcagedhensandlessinbroiler industries (Chauve 1998) due to the longer productive cycle related to the former mana- ment.Theprevalenceofinfestedfarmsrangesfrom60%inUK(Guyetal.2004;Fiddesetal.