The influence of temperature and humidity on the development of Dermanyssus gallinae populations in Dutch laying hen houses

Abstract

Dermanyssus gallinae (D. gallinae), also called the poultry red mite (PRM), is a blood-sucking ectoparasite known for their significant threat to egg-laying hens worldwide. Ninety-four percent of Dutch laying hen farms are infested with D. gallinae. Experimental studies have shown that the environmental temperature influences the development time of D. gallinae and that the mites in all their stages are very sensitive to dehydration. Field data are lacking. The objective of this field study was to quantify the influence of temperature and humidity during a 28-day period on the development of D. gallinae in Dutch laying hen houses. During two years, the infestation of D. gallinae was determined monthly on in total 17 flocks originating from 14 farms. The mean temperature and humidity per house were determined per week for the four weeks before the count of each determination of the D. gallinae infestation. Using linear mixed models, the influence of temperature and humidity inside the laying hen houses on the amount of D. gallinae (mg) and the growth rate in amount of D. gallinae was examined using two data sets. The first data set contained 84 D. gallinae determinations. The second data set is a subset of the first containing 10 D. gallinae determinations. The results showed that a rise in temperature of 1 ˚C inside the laying hen house during week 1 led to an increase of 20% in the amount of D. gallinae.