224 
IOWA ACADEMY OP SCIENCES. 
The abdomen is ovate, resembling that of T. tritici, Pitch, in an arrange- 
ment of bristles, except that the median pair on penultimate segment is 
but one-half as long as those on either side. 
Legs, especially femora and tibiae, thinly covered with short, coarse 
hairs which are replaced by bristles at apex of anterior and intermediate 
tarsal joints; inner margin of posterior tibiae feebly spinose; its apex and 
apex of its tarsal joints terminating in spines; anterior femora, moderately 
dilated. 
Anterior wings nearly attain tip of abdomen: veins heavy; inner mar- 
ginal vein very distinct; costal fringe rather heavy; costal vein bears from 
24-28 spines; radius, 18-19, those on basal half of vein separated into two 
groups of four each, the intervals between the rest growing wider toward 
the distal end of the vein; cubitus, 10-11; anal, 5; anal cell, 1. 
Color yellow, deeply tinged with orange on thorax and abdomen, 
faintly dusky along median line of thorax and abdomen; head and two 
basal joints of antennae, whitish; proximal portion of joints 3-6, dusky; 
remainder of antennae and spot near apex of tarsi, black; eyes, red-brown; 
ocelli, pale yellow; inner margins, orange red; spines and bristles black- 
ish; anterior wings and fringes tinged with dusky yellow. 
Described from a single specimen taken with T. tritici on 
aster at Ames, Iowa, September 16, 1893. 
Thrips tabaci, Lind. 
Schadiichsten Insekten des Tabak in Bessar. Abien., pp. 
62-63. (1888 ) 
Thrips lactucoe, n. sp. 
Female: Length, 1.40 mm. General color pale yellow, with two broad 
diverging stripes on middle of thorax, a narrow band at base and one or 
more spots at sides of abdominal segments brown. Form elongate; anterior 
border of head convex. Antennae seven-jointed, proximal joints pale, 
remaining joints black. Wings variable in size. Ocelli conspicuous, 
placed close together near posterior margin of vertex. Spines and bristles 
stout, on thorax, arranged much as in T. tritici; the cubital spines are 
grouped into two series, a basal group of seven, followed by three, more 
widely separated, on distal portion of vein. 
Head scarcely broader than long; outline seen from above semiovate;. 
occiput, feebly striate, one-half the length of the head, with shallow, 
longitudinal furrow each side behind the eye; gense, broad, full, prolonged 
posteriorly; vertex elevated, convex between the eyes, ascending and 
expanding towards apex, front margin arcuate; ocelli conspicuous, remote 
from anterior border of vertex, inner margins heavy, contiguous in front;, 
ocellar area elevated; ocellar bristles of medium size; eyes, moderate, 
pilose; a row of bristles on front, beneath insertion of antennae, is partially 
visible from above; a few microscopic bristles around orbits; antennal 
sockets prominent, easily seen from above; antennae approximate, seven- 
jointed; the intermediate joints elongate; joint 1 is one-half the length of 
joint 2, equal to or longer than joint 7, semiglobose; joints 2-5 are sub- 
equal in length; joint 2 is cupshaped, a little shorter but much stouter 
than any of the three immediately following; joints 3-5 are moniliform; 
