72 Parasitic Arthropods 



Treatment for the purpose of killing the mites is hardly necessary 

 as they attach feebly to the surface and are readily brushed off by 

 friction of the clothes. "Antipruritic treatment is always called for; 

 warm, mildly alkaline baths or some soothing ointment, such as zinc 

 oxide will be found to fulfil this indication." Of course, reinfestation 

 must be guarded against, by discarding, or thoroughly fimiigating 

 infested mattresses, or by avoiding other sources. Goldberger sug- 

 gests that farm laborers who must work with infested wheat or straw 

 might protect themselves by anointing the body freely with some 

 bland oil or grease, followed by a change of clothes and bath as soon 

 as their work is done. We are not aware of any experiments to 

 determine the effect of flowers of sulphur, but their efficiency in the 

 case of "red bugs" suggests that they are worth a trial against 

 Pediculoides. 



Various species of Tyroglyphidae (fig. 1 50/) may aboimd on dried 

 fruits and other products and attacking persons handling them, may 

 cause a severe dermatitis, comparable to that described above for 

 Pediculoides ventricosus. Many instances of their occurrence as such 

 temporary ectoparasites are on record. Thus, workers who handle 

 vanilla pods are subject to a severe dermatitis, known as vanillism, 

 which is due to the attacks of Tyroglyphus siro, or a closely related 

 species. The so-called "grocer's itch" is similarly caused by mites 

 infesting various products. Castellani has shown that in Ceylon, 

 workers employed in the copra mills, where dried cocoanut is ground 

 up for export, are much annoyed by mites, which produce the so-called 

 "copra itch." The skin of the hands, arms and legs, and sometimes 

 of the whole body, except the face, is covered by fairly numerous, very 

 pruriginous papules, often covered by small, bloody crusts due to 

 scratching. The condition is readily mistaken for scabies. It is 

 due to the attacks of Tyroglyphus longior castellanii which occur in 

 enormous numbers in some samples of the copra. 



Sarcoptidse 



The Sarcoptidse are minute whitish mites, semi-globular in shape, 

 with a delicate transversely striated cuticula. They lack eyes and 

 tracheae. The mouth-parts are fused at the base to form a cone 

 which is usually designated as the head. The legs are short and 

 stout, and composed of five segments. The tarsi may or may not 

 possess a claw and may terminate in a pedunculated sucker, or simple 

 long bristle, or both. The presence or absence of these structures 



