The Harvest Mites 61 



Most recent writers agree that, on man, they do not bore into the 

 skin, as is generally supposed, but enter a hair follicle or sebaceous 

 gland and from the bottom of this, pierce the cutis with their elongate 

 hypopharynx. According to Braun, there arises about the inserted 

 hypopharynx a fibrous secretion the so-called "beak" which is, in 

 reality, a product of the host. Dr. J. C. Bradley, however, has made 

 careful observations on their method of attack, and he assures us that 

 the mite ordinarily remains for a long time feeding on the surface of 

 the skin, where it produces the erythema above described. During 

 this time it is not buried in the skin but is able to retreat rapidly into 

 it through a hair follicle or sweat gland. The irritation from the 

 mites ceases after a few days, but not infrequently the intolerable 

 itching leads to so much scratching that secondary infection follows. 



Relief from the irritation may be afforded by taking a warm salt 

 bath as soon as possible after exposure or by killing the mites by 

 application of benzine, sulphur ointment or carbolized vaseline. 

 When they are few in number, they can be picked out with a sterile 

 needle. 



Much may be done in the way of warding off their attacks by 

 wearing gaiters or close-woven stockings extending from ankle to the 

 knee. Still more efficacious is the sprinkling of flowers of sulphur in 

 the stockings and the underclothes from a little above the knee, down. 

 The writers have known this to make it possible for persons who were 

 especially susceptible to work with perfect comfort in badly infested 

 regions. Powdered naphthalene is successfully used in the same way 

 and as Chittenden (1906) points out, is a safeguard against various 

 forms of man -infesting tropical insect pests. 



The question of the destruction of the mites in the field is some- 

 times an important one, and under some conditions, is feasible. 

 Chittenden states that much can be accomplished by keeping the 

 grass, weeds, and useless herbage mowed closely, so as to expose the 

 mites to the sun. He believes that in some cases good may be done 

 by dusting the grass and other plants, after cutting, with flowers of 

 sulphur or by spraying with dilute kerosene emulsion in which 

 sulphur has been mixed. More recently (1914) he calls attention to 

 the value of cattle, and more especially sheep, in destroying the pests 

 by tramping on them and by keeping the grass and herbage closely 

 cropped. 



