Nellie B. Bales 29 



Many mites are parasitic, for example, the Itch mites. Others, 

 like the cheese mites, feed on food substances, while a few are carnivorous 

 and beneficial. As a group the Mites are much simpler in organisation 

 than the spiders and though not very numerous in species, they cause 

 an immense amount of damage, owing to their short life cycle, their 

 rapid propagation, their powers of resistance and their means of distri- 

 bution. 



Species. 



Four species attack cheese. All of these are to be found on old 

 Cheddars and three species on Stiltons and Wensleydales. It must 

 be remembered, however, that although unpressed, ungreased cheeses 

 suffer most damage, old cheeses of any kind are liable to attack. 

 Further, these so-called cheese mites do not confine their depredations 

 to cheese, but will thrive equally well on flour, stored grain, dried fruits 

 and drugs, hay, etc., provided these are allowed to get damp. The 

 four species of Cheese Mite, wliich all belong to the same family of 

 Mites, are: 



(1) Carpoglyphis anonymns^ The Cheddar Mite. 



(2) Tyroglyphvs siro Stilton and Cheddar Mites. 



(3) Tyroylypluis longior „ ,, ,, 



(4) AleuroblKsfarinae ,, ,, ,, 



Carpoglyphus is readily distinguished from the other three species 

 by its greater opacity. It is of a deep cream colour when found on 

 cheese. Tyroglyphus siro is a somewhat sluggish species with heavy 

 body, short legs and long hairs. Tyroglyphus longior closely resembles 

 Tyroglyphus siro, but it is less heavily built and is exceedingly active. 

 Its hairs are very long and its legs pinkish. Aleurobius farinae, the 

 Flour Mite, has deep reddish brown legs and short hairs. The first 

 pair of legs in the male are very stout and spurred at the base. 



Life History. 



The life history, which is similar in all the species, consists of four 

 stages, the egg, larva, nymph and adult male or female. From egg to 

 adult stage occupies about four or five weeks. In working out the 

 life history the method suggested by Michael was used^. Glass cells 



^ The name Carpoglyphu.t means the fruit-cutter, because this species frequently 

 attacks dried fruits. Tyroglyphus means cheese-cutter, Aleurobius farinae the living 

 organism found in flour. 



- British Tyroglyphidae, i. p. 135, 



