10. BULLETIN" 553, U. S. DEPARTMENT 6E AGRICULTURE. 



daylight. The writer finds that normal feeding takes place during 

 the hours of darkness and that mites leave the fowl soon after 

 feeding. All stages of mites will go on a fowl, feed, and leave it in 

 less than two hours. In another experiment from 20 minutes to one- 

 half hour was found to be sufficient time for complete engorgement. 

 In one experiment about 30 per cent of a large number of mites put on 

 a fowl in an earthen jar at 10 a. m. were full fed when observed at 

 2 p. m. The fact that some mites will feed day or night accounts in 

 part for their very rapid increase about a sitting hen. 



Though mites feed at night, they do not necessarily all crawl off 

 the host before the fowls leave the roost. Both fed and unfed mites 

 may be retained in the feathers when the fowls are running about. 

 The number of such mites on a fowl seems to be small, but quite suffi- 

 cient to infest a new place. The length of time mites may remain on 

 a fowl after it has been on an infested roost is not certain. Experi- 

 ments designed to throw some light on this point developed that 

 nearly all mites leave the fowl by the end of the third night, but a 

 few stragglers may persist for several days. It would be advisable 

 for a person introducing new stock into his mite-free flock to use a 

 little caution if he would avoid an infestation. 



The author would suggest that new stock not known to be free of 

 mites be allowed to roost the first few nights on a new roost wrapped 

 with pieces of folded paper, preferably black. The object of using 

 the paper is to furnish a convenient place for mites to hide. The 

 paper may be examined, and if mites are found the fowls should be 

 kept on this roost five or six days, or until no more mites come off of 

 the fowls. If mites are discovered, by removing and destroying the 

 papers and treating the roost thoroughly with kerosene or crude oil 

 any danger of the mites getting back on the fowls can be avoided. 



The ease with which mites reach the host has a decided bearing on 

 the rapidity of increase. Hungry mites, though placed quite near a 

 fowl, have great difficulty in finding the host unless the means of 

 access is direct. This fact would account for the mite preferring 

 to hide on the roost. When mites are found all over the walls the 

 infestation must be a heavy one. To apply the above facts to aid in 

 control work, the roosts should not be connected up with the walls 

 of the chicken house unless some method of preventing the access of 

 the mite to its host is used. The same may be said of the nests. The 

 simpler and more isolated the roosts and nests, the easier it will be 

 to eradicate the mite. (For control measures see Farmers' Bulle- 

 tin 801.) 



HIDING HABITS. 



The direct rays of the sun act as a powerful killing agent when 

 mites are exposed to them. Mites put on a board in the direct sun 

 (July) were killed in a few seconds. Need of a suitable dark, pro- 



