268 
Hominoxious A rth ropods 
known as grocer’s itch. G. domesticus and G. pru- 
norum are old world species (fig. 150, d). 
ii. Dorsal integument not granulate; claws distinct; no 
prominent feathered hairs; ventral aperture small, 
j. Mandibles not chelate; elongate, and toothed below; 
body without long hairs; palpi enlarged at tip and 
provided with two divergent bristles. Species feed on 
decaying substances. Histiostoma Kram. 
jj. Mandibles chelate; palpi not enlarged at the tip, nor 
with two bristles. 
k. No clavate hair on the base of tarsi I and II; no 
suture between cephalothorax and abdomen. Live 
on bees or in their nests. Trichotarsus Can. 
kk. A clavate or thickened hair at the base of tarsi I and II. 
I . The bristle on the penultimate segment of the legs 
arises from near the middle; no suture between the 
cephalothorax and abdomen. The species, some 
of which occur in the United States, feed on dried 
fruit, etc. Ccirpoglyphus Robin. 
II . The bristle on the penultimate segment of the legs 
arise from near the tip; a suture between cephalo¬ 
thorax and abdomen. 
m. Cephalothorax w r ith four distinct and long bristles 
in a transverse row; tarsi I and II about twice 
as long as the preceding segment (fig. 150 f) 
.Tyroglyphus Latr. 
n. Some bristles on tarsi I and II near middle, 
distinctly spine-like; the sense hair about its 
length from the base of the segment. Several 
species in the United States belong to this 
group. 
nn. No spine-like bristles near the middle of the 
tarsi; sense hair not its length from the base 
of the segment. 
o. Of the terminal abdominal bristles, only two 
are about as long as the abdomen; 1 eg I 
of the male greatly thickened and with a 
spine at apex of the femur below. . T. farinas. 
00. Of the terminal abdominal bristles at least 
six or more are very long, nearly as long 
as the body. 
p. Bristles of the body distinctly plumose or 
pectinate; tarsi very long. . T. longior. 
pp. Bristles of the body not pectinate. 
q. In mills, stored foods, grains, etc. Third 
and fourth joints of hind legs scarcely 
twice as long as broad; abdominal 
bristles not unusually long; legs I 
