374 
Genus ACANTHOTHRIPS Uzel, 1895. 
This genus is represented in Illinois by two species, which may 
readily be distinguished from each other and from their previously 
described congeners by means of the following key. 
I. Inner-surface of fore femora with a single sub-apical tooth. 
a. Cheeks with prominent spine-bearing warts. No latero-dorsal 
white stripe. 
b. Wings of both pairs with a very prominent blackish longi- 
tudinal vein reaching nearly to tip 
A. magnafemoralis Hinds.* 
bb. Wings without conspicuous longitudinal vein 
A. doaneit Moulton, A. nodicornis (Reuter). 
aa. Cheeks without spine-bearing warts. A latero-dorsal white 
SHUT Spies ne bak a ey eh et Pe ge i ee A. albivittatus sp. nov. 
II. Inner surface of fore femora with a ‘‘long, sharp, and slightly curved’”’ 
booth near base sad. i... utr oe aware ieee eee A. sanguineus Bagnall. 
Acanthothrips albivittatus sp. nov. 
Female.—Length about 2.1 mm. Dorsal surface roughened with 
numerous microscopic tubercles; ventral surface smooth. General color 
(reflected light) dull mahogany brown, with a narrow latero-dorsal white 
stripe which originates at the posterior margin of the eye and terminates 
in a small spot at base of segment 8 of abdomen; on the head the stripe is 
slightly narrower than the basal antennal segment; on the prothorax it 
broadens posteriorly and includes an irregular reddish spot; at the an- 
terior mesothoracic margin it is broken up into two subequal triangular 
areas, from which it continues as a much narrower line to the base of the 
abdomen; it is lacking on the first abdominal segment, and extends un- 
interruptedly from the second to the eighth. General color (trans- 
mitted light) yellowish brown, with maroon-colored hypodermal pig- 
mentation; legs blackish brown, non-pigmented, shaded laterally with 
black; tarsi and inner surface of fore tibia paler; antenne uniform black. 
Head 1.4 times as long as wide; cheeks converging abruptly to eyes 
and to base of head; dorsal and lateral surfaces faintly reticulate, scarcely 
visibly spinose and not roughened by spine-bearing tubercles; postocular 
bristles long, pointed}. Eyes large, contained in length of head two and 
two-thirds times, and wider than the interval between them. Ocelli 
sub-approximate, opposite center of eyes. Antenne about one and 
one-fourth times as long as head; segments 3-6 urn-shaped; 7 and 8 
closely united, the latter conical; sense cones long, slender; segments 
3, 5, and 6 each with one on either side of apex; 4 with an additional 
*I have specimens of this species taken at Muncie and Urbana, Illinois. 
These bristles are wanting in A. magnafemoralis Hinds. 
