136 
THE PERIODICAL CICADA. 
made several years since by Mr. Pergande, who collected several of 
the mites and mounted and made preliminan^ studies of the others. 
Much of the material was collected by ^Ir. 
E. W. ^Vllis at Adrian, Mich., in 1885, the balance 
by Mr. Pergande in the District of Columbia and 
near-by Cicada districts in Virginia in the same 
year. 
THE ORIBATID MITES. 
Fig. 64.— Mito egg parasite, 
Pediculoides ventricosus. 
(Author's illustration.) 
The members of the family Oribatidse have 
the popular designation of '^ beetle mites," aris- 
ing from their possessing a hard cliitinous cover- 
ing causing them to resemble minute beetles. 
Some six distinct species were found in the adult 
stage associated with the eggs of the Cicada, and 
several nymphal forms — the latter being often 
showily colored and the principal feeding stage 
of these mites. 
The following are Mr. Banks's determinations 
of the oribatid material: (1) Orihata sp., collected by Mr. Pergande in 
the District of Columbia in July, 1885; (2) Orihatella sp. (fig. 61), col- 
lected by Mr. E. W. Allis at Adrian, 
Mich., in October, 1885; (3) Oripoda 
elongata Bks., MS. (fig. 62), collected 
with the last; (4) Oppia pilosa Bks. 
(fig. 63), also collected at Adrian, 
Mich.; (5) Orihatula sp., collected 
by Mr. Pergande in the District 
of Columbia and in Virginia in 
July, 1885; (6) Oribatid nymphs, 
collected with the last and possi- 
bly belonging to the same species; 
(7) HoplopJiofa sp., collected by 
Mr. Allis in Michigan in October, 
1885. 
MISCELLAXEOrS PREDACEOIS MITES. 
The following mites have well- 
known predaceous habits and for 
the most part are miscellaneous 
feeders, subsist ino; on almost anv l'^i«- '■>5.-Mite egg parasite, ryro^Z.yp/^r/.rora- 
. . ^ " philus. (Author's illustration.) 
available animal matter, such as 
s()ft-lK)died insects, insect eggs, and various animal and also vegetable 
food ])ro(lucts. 
