142 On the Transformations of the Red Mites. [ March, 
legs 7-jointed, palpate, with two minute terminal hooks, the front 
pair longest; the two front pair widely separated from the two hind 
pair; mandibles unguiculate; palpi large, free, the penultimate 
joint strongly ungulate, and the terminal joint forming a movable 
thumb upon it. Larva 6-legged, parasitic; defined under the gen- 
eric names Astoma, Leptus, Lepostomus and Ocypete. Many species 
have been described in Europe, but the one in question differs 
from all of them as given by Gervais.* 
Trombidium locustarum Riley —Egg, 0.12 mm. in diameter, 
spherical, full of granulations, pale orange-red in color, becoming | 
more pointed at one end before hatching (Fig. 1¢), the shell split- 
ting across and the severed sides rolling toward each other 
when vacated (Fig. 12). 
rva.—When newly hatched, pale orange-red, 0.14 mm. long, 
ovoid, the body with but three transverse sutures, one anteriorly, 
one between first and second, and another between second and 
third pair of legs; dorsum with several transverse rows of about 
six piliferous points; head somewhat narrowed, showing four 
minute swellings, each giving rise to a rather long hair; mouth- 
parts small and indistinct, with a dusky, granular spot at their base; 
legs 6-jointed, inclusive of fixed coxal piece, the third joint 
longest, hind pair somewhat longer than the others; all tipped 
with two well developed claws, those on front pair the longest; 
what appears to be a rudimentary sub-cutaneous fourth pair; no 
anal sete. 
Full 
distended and elongated, the elongation being principally from 
the posterior dorsal portion so as to bring to view four hairs at 
the end; body showing two principal transverse constrictions, one 
about the middle, the other above it, while the whole surface is 3 
finely andtransversely striate. 
ong, one-half as broad. Either pale yellow of 
orange-red, polished, swollen and rounded anteriorly, more taper- 
ing posteriorly, the dorsum well arched; two transverse impres- — 
sions, at first noticeable but subsequently obliterated; palpt and . 
legs formed under the larval skin, their ends finally projecting — 
from it and more or less free; traces of the shriveled larval legs : 
_ widely separated. : 
Adult—When first from pupa the color is orange-red, with @ . 
distinct transverse constriction about the middle, anda deep trans- 
diameter, armed wi h rather long 
1 Suites à Buffon. Aptéres, 1844. 
ð 
own larva.—1.6 mm. long, with the whole body greatly 
