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long it was believed that they lived on the juices of plants and 

 only under certain conditions became blood-suckers. They, how- 

 ever, live normally upon invertebrate hosts, especially insects, and 

 are only accidental parasites on higher animals. M. pusillum attacks 

 man very severely and is troublesome also to horses, cattle, sheep, 

 rabbits, dogs and cats. It has been reported from England, France, 

 Belgium, Holland and Germany, occurring during September, October 

 and November. 



Thrombidium strialiceps, Oud. (striated European chigger-mite) is not 

 so common or important a pest as the two above-mentioned, but has 

 been found on man, the dog, cat and domestic fowl in France, Belgium 

 and Holland, its normal hosts being chiefly species of Diptera. 



Microthroynhidiuni {ahmmishi] (kedani mite), the adult form of 

 which is unknown, is an orange-red chigger-mite, which in certain 

 parts of Japan has been associated with a fatal disease known as 

 river fever. It appears that the lesions caused by its attacks afford 

 a point of entrance to the bacteria which cause the fever [see this 

 Review, Ser. B, vi, pp. 21, 50]. 



M. wichmanni, Oud. (Ceram chigger-mite), an East Indian species 

 which by its bites covers the body with inflamed lumps and produces 

 a serious disease. Besides being found on man, this mite has been 

 recorded from a bird, Goura coronala. 



Schongastia vandersandei, Oud., is a bright red mite which in 

 New Guinea climbs shrubs and bushes whence it is brushed on to 

 the bodies of the larger animals as they pass by. It gets under the 

 skin, causing a disease known as shrub-itch. It has also been found 

 on Goura coronata. 



Microifirombidium tlalzahuatJ, Murray (Mexican chigger-mite) is an 

 oval, bright orange-yellow mite that attacks the eyelids and axillae. 

 The natural hosts of this mite have not been determined and there 

 is no record of it attacking mammals other than man. 



The American chigger-mite, which has long been recorded under 

 the name of Lepfus mnericanus, though it belongs to an undescribed 

 genus and species, is barely visible to the naked eye and infests chiefly 

 the scalp and axillae. Nothing is known of its natural hosts or of 

 its occurrence except in the upper Mississippi valley. 



The irritating chigger-mite, also belonging to an unknown genus 

 and species, which has frequently been mentioned in American litera- 

 ture under the name L. irritans, is of minute size. It is most trouble- 

 some, causing intense irritation and swelling on all parts of the body. 

 It has been thought that it may be identical with the common locust- 

 mite frequently found on the wings of grasshoppers in the upper 

 Mississippi valley, but the fact is not established. 



En thrombidium trigonum, Herm. (locust mite) was first reported in 

 1868 on the Rocky Mountain locust. An adult has been successfully 

 reared from a larva infesting Melanoplus bivittatus. The adults show 

 a decided preference for grasshopper eggs. The larvae cannot be 

 induced to attach themselves to man, and have never been reported 

 from man or domestic animals in Europe. So far as is known, the 

 hosts of the locust mite are confined to four famifies of Orthoptera, 

 namely : — Acridiidae, Tettigoniidae, Gryllidae and Mantidae. 

 In America it has been found on the following species : — Melanoplus 

 differentialis, M. spretus, M. angustipennis, Spharagemon bolli and 



