THE CHICKEN MITE. 9 



winter. The lowest temperature experienced by any of the mites 

 under observation was 15° F., the highest 97.5° F. Adults and sec- 

 ond-stage nymphs, during the months of July, August, September, 

 and October, lived longest when moisture was applied — from 91 to 

 98 days. Under dry conditions the mites lived 56 to 85 days. Dur- 

 ing the months of August, September, October, November, and De- 

 cember mites under dry conditions lived from 100 to 108 days. The 

 longest that adults which had never fed as adults lived was from 

 88 to 96 days; this was during the months of October, November, 

 December, and January. All stages on a stick of wood lived 91 to 

 113 days in the months of September to January, inclusive. All 

 stages in a glass chimney with a cracked egg lived more than 107 days 

 during the same months. 



First-stage nymphs have about the same period of longevity as the 

 other stages. During the months of July to November, inclusive, this 

 stage, when moisture was added, exhibited a longevity of 81 days 

 under both moist and dry conditions. Second-stage nymphs seem to 

 be the longest lived. During the months of September to January, 

 inclusive, individuals in this stage lived 139 days. Females which 

 had completed oviposition lived from 29 to 39 days during September 

 and October, when kept under dry conditions. Females feeding and 

 depositing continuously live longer than those not allowed so to feed 

 and deposit. In the life-cycle experiment some females lived longer 

 than 53 days. 



One may therefore conclude that the mite can be starved out of a 

 chicken house by keeping fowls and other animals away from the 

 house for four months during the summer season and five months 

 during the cooler season. It is probable that with uniformly cold 

 weather, as in the Northern States, the longevity would be some- 

 what greater than in these experiments, all of which were conducted 

 at Dallas, Tex. 



FEEDING AND HIDING HABITS OF MITES. 



FEEDING HABITS. 



The usual habit of the mite is to feed at night. An experiment was 

 conducted to determine whether mites feed and leave the fowl imme- 

 diately or whether they have a particular time for dropping, such 

 as just before daylight, as one writer claims. Two hours before dark a 

 fowl was put on a roost containing a large number of hungry mites. 

 Very few mites ventured far out of their hiding places at this time. 

 A few did go to the fowl. At dark, two hours later, only four mites 

 were found to have fed and left the fowl. One hour after dark 

 nearly 600 mites (adults and first and second stage nymphs) had fed 

 and left the fowl. One and a quarter hours later 535 more fed mites 

 left the bird. Mites continued to drop in smaller numbers until after 



