18 BULLETIN 986, U. S. DEPARTMENT OF AGRICULTURE. 



Dr. Maurice C. Hall, of the Bureau of Animal Industry, reports 

 excellent results from the use of sulphur ointment against the larvae 

 after they have become attached. 



Commercial alcohol (95 per cent) has been used by several ac- 

 quaintances and by the writer himself to good advantage against 

 the chiggers attached to the skin. When the free larvae are im- 

 mersed in alcohol and observed under the miscroscope they are seen 

 to die in short order, usually in from 1 to 3 minutes. The alcohol 

 is an excellent acaricide and also a good antiseptic for the unabraded 

 or slightly abraded skin, and has a further advantageous effect in 

 hardening the dermis. It should be applied quite freely and the ap- 

 plication repeated two or three times. 



Any of the lighter oils kill the larvse quite rapidly, and can be 

 used to advantage against the larvae if the latter are confined to 

 a small area on the body. Sulphur acts slowly, but if applied with 

 soap and allowed several minutes to act should give good results. 



PALLIATIVES. 



To those who go little afield and are thus ignorant of some .of 

 nature's ways warnings that preventive measures should be taken 

 are usually but little heeded, hence it is necessary to give directions 

 in the- use of palliatives — the most unsatisfactory of all measures. 

 Undoubtedly most of the so-called palliatives are of value chiefly, 

 if not entirely, because of their acaricide action or because they act 

 antiseptically, or in both these manners. 



In the Panama Canal Zone, according to Dr. W. A. Taylor, Chief 

 of the Bureau of Plant Industry, a saturated solution of salicylic acid 

 in alcohol, with a little olive oil added, has been used to good advan- 

 tage as a palliative. Both he and Mr. H. H. Bennett, of the Bureau 

 of Soils, used this mixture with very beneficial results in the Canal 

 Zone. 



In the Southern States, according to Mr. Bennett, butter or lard 

 with a liberal mixture of table salt, or pure kerosene oil, is fre- 

 quently used as a palliative. With regard to their benefit he says: 

 "I am still not convinced that they are more than moderatety 

 efficacious * * *." 



Among the other substances recommended as palliatives are the 

 following: Ammonia, cooking soda, dilute solution of iodine, cam- 

 phor, and alcohol. Statements made to the effect that an acid toxin 

 is injected by the larvse are not based on observed fact or experi- 

 mental demonstration. We do not know even that a toxin is injected 

 by these acarids. As before stated, the intelligent use of palliatives 

 awaits experimentation on the nature of chigger injury from the 

 physiological standpoint. 



