446 



SANITARY ENTOIVIOLOGY 



petroleum (plate XXVIII). It is usually best to thin each of these sub- 

 stances with one-third kerosene. Following this treatment a simple roost 

 (fig. 87) should be constructed, preferably supported by four posts driven 

 into the ground or attached to the floor, the roost poles being held in 

 place by notches on cross bars resting in similar notches in the supporting 

 posts. None of the roosts or supports should touch the walls. One or 

 tAvo applications of the carbolineum or petroleum to these roosts with a 

 brush will usually suffice in destroying the infestation, although it is 

 advisable to make frequent examinations to determine if all of the ticks 

 are destroyed. The chicken mite Dermanyssus gallmae is controlled by 

 the same procedure. 



Other American Species of Ticks. — There are several other kinds of 



Fig. 87. — Model chicken roost (Bishopp). 



ticks of economic importance in this country. Among them should be 

 mentioned the Lone Star tick which is frequently met with in the South, 

 East, and Central States ; the Gulf Coast tick which produces consider- 

 able irritation by attacking the inside of the external ear of horses and 

 cattle in the coastal region ; the tropical horse tick which is to be found 

 only in extreme southwestern Texas, usually attached deeply in the ears 

 of horses and mules ; and the widely distributed American dog tick which 

 is sometimes sufficiently abundant to greatly annoy man and other animals. 

 All of these species except the tropical horse tick, drop for their molts and 

 are therefore rather difficult to control. Dipping in arscnicals, especially 

 if carried out at weekly intervals, will of course reduce their numbers 

 considerably. In regions where dipping vats are not generally available, 

 hand picking or the application of kerosene emulsion, some of the creo- 

 sote stock dips, or arsenical dips with a rag or spray pump are advisable. 

 The treatment of dogs should receive special attention. The tropical 



