73 



mites found in salt water. Besides these there are the Gamasids, many of which are para- 

 sitic on insects, while some are trpublesome to birds and other animals, Gumasus coleop- 

 tratorum and G. inarginalis are found on various beetles. Uropeda vegetans also attacks 

 beetles. When a beetle is infested with this mite, it seems as if covered by a large 

 number of small fawn-coloured shining convex scales, attached to various parts of tke 

 underside of the body, and on the parts infested, covering the body so completely that 

 none of it can be seen. They are not easily detached, and when forcibly removed they do 

 not fall off but hang by a fine thread, exuded from their bodies, which is attached to the 

 beetle. There is also the forage mite, which is found in Europe, in great numbers 

 amongst old hay, and which when shaken down from the rack, on the heads and necks of 

 the animals feeding on it, occasions them much annoyance. 



Dermanyssus avium 



is the so-called tick, that infests domestic poultry, canaries and other cage birds. Fig. 61 



gives a good idea of this creature, which is not much larger 

 than a cheese mite. It lives especially in poultry houses, 

 and on their inhabitants, and from these the mites sometimes 

 migrate to the persons who have charge of them, and occa- 

 sion them considerable annoyance. These mites also infest 

 the cages of singing birds, and harbour about the crevices 

 in the cage, and about the perch, from which they sally 

 during the night, and burrow among the feathers of the 

 sleeping birds and suck their blood. Other species belong- 

 ing to this genus and allied genera feed on swallows, 

 pigeons, doves and other birds, also on bats, indeed on this 

 subject, did space permit, we might enlarge almost indefi- 

 nitely, since there are species infesting almost every species of bird, beast and reptile in 

 existence, as well as many insects, and on a variety of vegetable substances, especially 

 mosses and fungi. One species has been found in the abdominal cavity of a dead flea, 

 thus : 



' ' The little fleas, that do so tease, 

 Have smaller fleas that bite 'em, 

 And these again have lesser fleas, 

 And so ad infinitum." 



In the genus 



Tyroglyphus 



are included several interesting and well known species. Tyroglyphus entomophagus feeds 

 on animal substances, being very partial to the dried insects, in the collections of the 

 entomologist. In fig. 62 we have Tyroglypus mycophagus, a closely allied species, highly 



magnified; they are both very minute, yet easily seen 

 with the naked eye. When once T. entomophagus 

 gains accesstoacollectionits presence is soon evidenced, 

 by the dust which gathers on the bottom of the 

 drawers, under or about the insects on which they are 

 feeding. If allowed to proceed unmolested, they 

 Fi g> 62. soon so far devour the bodies of the specimens so 



attacked, as to reduce them to a mere shell, which 

 frequently falls to pieces in the handling. They are especially destructive to moths and 

 butterflies. As soon as any appearance of dust occurs under any of the preserved insects 

 in a case, such specimens should be at once attended to, and treated with a liberal appli- 

 cation of Benzine, which will kill the mites without injuring the subjects infested. Insects 

 which have not been thoroughly dried before being placed in the cabinet, are most liable 

 to attacks, especially such as have been bred. Exposure to dampness also favours the 



