8 BULLETIN 421^ U. S. DEPAETMENT OF AGKICULTUEE. 



and front of a distinct elevation on top of head between eyes. Head liglit brown with 

 light yellowish longitudinal stripe on each side between eye and ocelli. Maxillary 

 palpi three-segmented, short, small; labial palpi minute. Antennae eight-segmented, 

 slender, nearly three times as long as head; relative lengths of segments as follows: 



1234 5 678 



5 8.8 16.6 12.2 11 8.6 4.3 10.5 



Segment one cylindrical, three-fourths as broad as two, which is barrel-shaped and 

 annulated; remaining segments narrower than these two and more elongated; three 

 and four fusiform; seven and eight nearly cylindrical; eight very slender; one, two, 

 and three nearly concolorous, light yellow with tinge of gray or brown on one and two ; 

 four and five light yellow in basal half, shading to light brown on apical half; six, 



Fig. 7. — Adult female of sugar-beet thrips. Enlarged. (Original.) 



seven, and eight uniformly chocolate brown; segments two to five annulated; spines 

 slender, light colored. 



Prothorax transverse, about one-fifth wider than the head, twice as wide as long and 

 shorter than the head ; sides rounded ; without conspicuously large spines. Meso thorax 

 about one and two-thirds times as wide as the head; anterior angles prominent; meso- 

 notum with deep incision on posterior margin ; metanotum with four spines standing 

 in a square near its center. Wings present, long, about one-sixteenth as broad as long; 

 fore wings broadened at base, with two longitudinal veins, the second branching from 

 the first not far from the base of the wing. Spines upon veins of fore wing stout, 

 dark colored, and set at uniform distances; costa bears seventeen to twenty, fore vein 

 fourteen to seventeen, hind vein ten to thirteen, scale three to five besides pair at its 

 tip; spines on basal fourth of wing are light colored, smaller, and much less conspicuous; 

 anterior fringe on both wings fairly long and stout; posterior fringe long, slender, and 

 dark colored. Wings grayish brown to dark gray, lighter between the longitudinal 

 veins; three nearly white cross bands; one across base before branching of veins, 

 another at three-fourths the length of wing and the third across the tip. Legs: All 

 tibiae, tarsi, and fore femora yellow; middle and hind femora dark brown, yellow only 



