^ ■ EXTERNAL PARASITES 77 



Symptoms of Tromhkliam Infestation. — By means of its 

 conical mouth parts, referreci to above, it wounds the skin 

 and sucks bk)od. The engorged parasite is 1)1 ue to red in 

 color, depending u])on the quantity of blood taken into the 

 digestive tract. During the summer of 1911 tlie author ob- 

 served one infested iiock of chickens in which the atfected 

 birds showed symptoms similar to birds infested with lice. 

 They became unthrifty, ceased laying, sitting hens deserted 

 their nests, all exhibited unkempt appearance of the fealhers 

 and many died. IMany were found dead under the roosts of 

 mornings. Examination of the nests, roosts and birds revealed 

 millions of the parasites. This was in the month of August. 



Treatment: Eradication. — The same treatment as for lice 

 Avill be found very effective. Absolute cleanliness, plenty of 

 kerosene or some standardized coal tar disinfectant dip re- 

 peatedly applied to the roosts, and especially the under sides, 

 cracks where the roost pole rests on its support, and the inside 

 of the nests, will prove of value in combating the condition. 



There is common belief that tobacco clippings, sulphur, paris 

 green, and a host of liquids, are great destroyers of these formid- 

 able foes of the poultry house, but no one so far as we could find 

 has actually made tests to prove it. It was thought best to try 

 a score of the more common agents used. 



Mode of Tests. — The tests were run either in open tumblers or 

 sauce dishes so as to have an abundance of air present and to 

 have the tests as nearly under normal conditions as possible. 



Agents Used. — The agents used fall into three classes, namely: 

 dry powder, liquid and liquids that give off gases as well as powder 

 that gives off gases. Tests were made with sulphur, air slaked 

 lime, paris green, naphthalene, gasoline, carbolic acid, insect powder, 

 tobacco stems and dust, crude carbolic acid, five per cent carbolic 

 acid, one per cent kreso dip, two per cent kreso dip, five per cent 

 naphthalene in kerosene and pyrethrum. 



^^ulphur. — Flowers of sulphur was placed in the bottom of two 

 saucers and several hundred mites, some very vigorous, were placed 

 on top of the sulphur. At the end of five hours the mites were 

 still walking over the sulphur. Dry powdered sulphur has appar- 

 ently no destructive action upon them. 



Air Slaked Lime. — Air slaked lime was placed in the bottom of 

 a tumbler. At the end of twenty-four hours the mites had accumu- 

 lated in a cluster in the center of the dry lime. Upon being poured 

 out onto a paper they were found to still remain vigorous. Dry 

 air slaked lime has apparently no injurious effect upon them. 



Paris Green. — Dry paris green (powder) was placed in the bottom 

 of a tumbler and several hundred mites placed in the powder and 

 stirred. At the end of forty-eight hours the mites had formed in 

 a cluster in one edge of the powder. Upon being removed they 

 were found to be as vigorous as before being placed in the paris 

 green. Dry paris green apparently has no ill effect upon mites. 



Xaphthalene (powdered moth balls). — A quantity of pulverized 

 moth balls were placed in the bottom of a tumbler and several hun- 

 dred vigorous mites placed on the surface. At the end of thirty 



