1877.] The Museum Mite. 479 
THE MUSEUM MITE. 
BY ANDREW MURRAY,} 
q Tyroglyphus entomophagus is the smallest of all the known 
species of this genus. It is remarkable for the parallelism of 
the sides, and cylindrical appearance of the body, and for its nar- 
rowness, especially in the female. Its legs are shorter than in 
the other species. 
It is a species only too well known to entomologists. It takes 
up its abode in entomological collections, in the interior of the 
body, or on the surface of the insects, and in the dust which gath- 
ers at the bottom of the drawers or boxes. Large insects, with 
the body full of fatty particles, those which have been brought 
up in captivity, and which have not paired, and those which 
have become greasy (to use the technical expression), are the 
most liable to attack. Certain families of Coleoptera, the large 
Scarabwide, like Oryctes and Geotrupes, the Lucanide, the Car- 
abide, the Dytiscide, and the Hydrophilide, the Cerambycide, 
the large or badly dried Blaptide, may often be seen covered on 
the surface with excrement and eggs, under the form of white 
dots, and sometimes contain a considerable number of these Ty- 
roglyphi in the interior of the body. 
The body of the large, especially the nocturnal Lepidoptera, 
the Cicade amongst the Hemiptera, the Earwigs, etc., have them 
likewise, and the quantity sometimes furnished by such insects, | 
where the mites have once obtained a footing, is truly enormous. 
The Tyroglyphus entomophagus may be found running upon 
the back of dead insects, and may be seen without the aid of the 
microscope. According to M. Perris it gnaws the down and the 
hairs of the insects attacked. It is, however, chiefly in the in- 
side of their body that it lives ; it gnaws and dilacerates all sub- 
stances that are soft or deprived of chitine ; hence they are spe- 
cially destructive to Lepidopterous insects. In handling insects 
that have been attacked by these Tyroglyphi, we are apt to 
cause the articulated pieces of which the ligaments have been de- 
Stroyed to fall asunder, and then there issues from the body a 
friable matter in which the living Acari swarm. + 
The friable matter which falls out, when the body of insects 
gnawed by the Tyroglyphus entomophagus is shaken, is composed 
t, of the excrement of these animals in the form of little round- 
oe from Economic Entomology : Aptera. By Andrew Murray. Lon- 
» 1877. j 
