forms of related species, I believe them to be the sexed individuals, and 
therefore describe them here. 
Wingless Oviparous Female?—somewhat smaller than the vivip- 
arous female, easily recognized by the absence of the peculiar thick, an- 
gular bent, scale-like hairs which constitute the vestiture of the vivip- 
arous female at all ages, these being replaced by fine short erect hairs, 
straight or nearly so, a little longer and more distinct in younger speci- 
mens. Antenne clearly 4-jointed in all specimens seen, Spots about 
and near spiracles usually well marked. Genital valves distinct in adult. 
No trace of sensoria other than the usual ones on the last two antennal 
joints, Otherwi ise as in the viviparous female. 
Length 1.85 mm., breadth 1.25 mm. : 
Male?—Small, more oval, abdomen less expanded, color as in the 
viviparous female, surface clothed with long erect hairs, less fine and 
more conspicuous than in the supposed oviparous female. Antenne dis- 
tinctly 4-jointed, I and IT combined about equal to IV; HI a little 
longer. Beak somewhat longer than in the preceding forms. Rows of 
abdominal spots more approximate on each side, hairs of back arranged 
in rows more distinctly than in the young of the form just described: 
Anal plate more projecting, eighth segment more prominent. Other- 
wise not different from the forms already described. Sensoria of last 
two antennal joints as usual. 
Length .8 mm., breadth .t1 mm., antenna .28 mm. 
As in related species, a careful search fails to reveal any other 
sensoria, such as those which appear in the sexed individuals of Aphis 
maidiradicts. 
Tire Wootty Grass Root Louse. 
(Rhizobius spteatus, n. sp.) 
(Plate X., Fig. 4.) 
Another grass root louse, belonging to the genus Rhizobius, and 
here described as R. spicatus, has been encountered oc ceasionally on corn 
in our studies of the insect enemies of that plant. It is represented in 
our collections by six lots of specimens, of which one was obtained from 
a corn field at Urbana April 1, a second from grass roots July 20, a 
third from corn roots at Tamaroa, Perry county, October 5, ‘another 
from roots of crab-grass (Panicum proliferum ) at the same time, an+ 
other from grass roots October 10, and the last from a corn field Decem- 
ber 5. 
The April and October specimens were adults, except that with 
those taken October 5 were sometimes a few young,—full grown fe- 
males placed singly in small cavities under eround, each being accompa- 
nied by a small group of young. These cavities were at various depths, 
from just below the surface to six inches under ground, and were lined 
with a bluish waxy excretion, doubtless derived from the woolly coat- 
ing of the root lice. 
The July specimens and those brought in December 5 were young, 
the latter about half grown. 
B, 
ot 
. 
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