104 
THE PERIODICAL CICADA.. 
predaceous habits and for the most part are miscellaneous feeders, sub- 
sisting on almost any available animal matter, such as soft-bodied in- 
sects, insect eggs, and various animal and also vegetable food products. 
Fig. 55. — Mite egg parasite, Iphis ovalis 
(original). 
Fig. 56. — Cheyletus sp., mite egg 
parasite of Cicada (original). 
Perhaps the mite most commonly found with the eggs of the Cicada 
is Petliculoicle.s ventricosus. This species has a very general feeding- 
habit and is often an active agent in the destruction of the eggs or 
young of insect pests. In breeding cages it is 
often a nuisance by destroying the smaller 
insects being kept under observation. The 
general form of the male and of the mi impreg- 
nated female of this mite is similar to that of 
the next species listed. The gravid female, 
however, develops an enormous globular exten- 
sion from the tip of her abdomen, as illustrated 
in the accompanying figure (fig. 53). 
Another predaceous mite, not at all uncom- 
mon, in the egg slits both in the District of 
Columbia and in Michigan, is a species of Tyro- 
glyphus (fig. 54), very near T. longior, which 
species it very closely resembles. The species 
named is a widely distributed one and frequently 
occurs also in breeding cages, and often becomes 
very troublesome from its presence in enormous 
numbers on various food substances in the lar- 
der. A smaller species of the same genus was found with the Cicada 
eggs, but the material is not in good enough condition to make its 
identification possible. 
Fig. 57. — Bdella sp., mite par- 
asite of eggs of Cicada — 
greatly enlarged (original) . 
