October, '19] WOOD: depluming mite control 403 



to pluck a few feathers from several regions of the fowl and examine 

 with a lens the scales around the base of the quill. The head of the 

 mite may be seen projecting slightly through the scale which is removed 

 with the feather. This scale is larger than on a normal feather. It 

 is often more difficult to find them on broken feathers than on whole 

 feathers for the live mites are more often found on the whole feathers. 

 Though in bad infestations either live or dead ones may be found on 

 any feathers. As many as three adults have been found in one scale. 



The adult female gives birth to larvae still encased in the egg sack, 

 the larva extricating itself from the egg sack soon after birth. Mites 

 were found on feathers taken from back, top of wing, near vent, breast 

 and thighs but none from tail or primary or secondary wing feathers. 

 In the tunnel with a female were found thirty-one larvae. 



The damage to the plumage is very evident. Infested fowls have a 

 ragged appearance with a good many broken feathers or perhaps bare 

 spots. This appearance is more evident in the summer and fall than 

 it is soon after molting. It is quite evident that any damage done to 

 plumage would be detrimental to show birds. We believe also that 

 more injury is done to poultry generally by this mite than is com- 

 monly supposed. There seems to be some itching which may result 

 in feather pulling, causing some hens to become quite bare. The time 

 fowls spend in combating this pest would better be spent in resting or 

 getting food, thus producing increased growth or larger egg yield. 



This mite seems to be quite generally distributed, according to 

 reports of various authors. We have collections from Texas, and Mr. 

 O. G. Babcock has sent us collections from Tennessee, Missouri and 

 Mississippi. Even in infested districts, however, many flocks appear 

 to be entirely free from the mites. 



The following substances were tried out in preliminary control experi- 

 ments: Lime-sulphur, potassium sulphuret, tobacco-sulphur, dry 

 sulphur, arsenical dip (B. A. I. formula, white arsenic 8 lbs., sal soda 

 24 lbs., pine tar 1 gal., and water to make 500 gallons), kerosene emul- 

 sion, sulphur and sodium fluoride, sodium fluoride, soap and water, 

 sulphur, soap and sodium fluoride. Sodium fluoride was included in 

 the last two formulae to see if both lice and the depluming mite could 

 be killed in one treatment. 



Lime-sulphur: One lb. lime, 2 lbs. sulphur, 1 g:il. wafer. Dilution, 1 to 20 parts 

 water. F'ourteen days after treatment no live mites could be found; all lice were not 

 killed. 



Potassium sulphuret: One-half oz. soap, ^ oz. potassium sulphuret, 1 gid. water. 

 Sixteen days after treatment some mites found alive. 



Tobacco-sulphur: Three teaspoonfulls "Black Leaf 40," (> ozs. sulphur, 2\ Ral. 

 water. Eleven days after treatment no Iiv(> mites or lice found. 



Dry sulphur: Tlioroupilily dusted with flowers of sulphur. Twelve days after 

 treatment no live mites found. 



