o 



2 Annals Entomological Society of America [Vol. Ill, 



Many other similar letters from towns in Ohio were received 

 by Dr. Schamberg, particularly from Zanesville, Columbus, \'in- 

 cent, Springfield, etc., where the affection is popularly believed 

 to be due to "chiggcrs." A physician from the last named town 

 stated that in the fall of 1908, during harvest and threshing time 

 he saw in Washington County some 87 cases of the disease in 

 question. It affected the harvesters and threshers. This spring 

 he observed 38 cases from contact with straw ticks refilled with 

 straw of last fall's crop. The disease is said to have been more 

 prevalent last year (1908) than ever before. Information has 

 come from Columbus, Ohio, that potters who used straw for 

 packing crockeiy ware have been so badly attacked at times that 

 the entire force of packers has been off duty. ]\lany times a 

 whole car-load of straw has been so aftected that the use of it 

 has been abandoned. In Springfifild, Ohio, it is said that the 

 disease was so bad a year or two ago in the lowlands west of this 

 city as seriously to hamper the progress of the construction of a 

 large sewer. This, however, might ha\-e been due to attack 

 by other mites, notably to Trombidium larvae. In Zanesville, 

 Ohio, the potters have been obliged to abandon the use of straw 

 and employ "prairie hay" for packing purposes. 



Dr. Schamberg was also infoiTned b>' a physician of Pittsburg 

 that a young woman patient has suffered from an affection closely 

 resembling, if not identical, with the one under consideration, 

 each time that she has assisted in emptying cases of dishes packed 

 in straw. Both the physician and the patient had come to believe 

 that something in the straw was the cause of the eruption. 



Indeed, so nearly did the territory from which these com- 

 plaints came to us, coincide with that affected by the joint worm, 

 that it created the suspicion, not only among those engaged in the 

 investigations, but even among farmers themselves, that there 

 must be some connection between the two phenomena. Very 

 many of these cases were brought to the notice of practicing physi- 

 cians, but they were themselves at a loss to account for the preva- 

 lence of this dermatitis, many of them supposing it to be some 

 species of rash that was more or less contagious, the exact nature 

 of which they did not know. 



Among these physicians was Dr. Lyman T. Rawles, of Hunter- 

 town, Indiana, who in ]\Iay, 1909, took up a careful study of a 

 numlier of cases of this dermatitis that had come under his per- 

 sonal observation as well as those of some of his associates. Dr. 



