NO. 1310. NORTH AMERICAN THYSANOPTERA— HINDS. 141 



projections, the inner edges of which are parallel and the black mark- 

 ing tapers to a point anteriorly; on each side of these peculiar proc- 

 esses stands a long, slender spine; at about the middle of each side of 

 ninth segment is a very al)rupt, angular, chitinous projection shaded 

 almost black, supporting on the inside of it an exceedingly short, 

 stout, dark brown, blunt spine; other spines on this segment slender, 

 but not very long. Segment ten is blunt at end and bears a row of 

 short, small spines above, close to hind edge; nine is cut out on upper 

 side over about half of ten, which at tip does not (][uite reach to tip of 

 nine or under side; abdomen 3'^ellow-brown. 



Described from four specimens. 



Cotype.—Q>'^it. No. 6326, U.S.N.M. 



Food plan ts. — Oats. Fedkica pratenHiS. 



Ilahitat. — Pennsylvania, Massachusetts. 



Life history unknown. 



This species was verv alnuidant upon and caused much damage to 

 oats at State College, Pennsylvania, during the summer of 1898. 



Genus SERICOTHRIPS Haliday. 



Bod}^ broad and having a silk}' luster due to the presence of numer- 

 ous minute spines on the abdominal segments. Head fully one and 

 one-half times as wide as long. Eyes large and protruding; ocelli 

 present in both sexes. Antenna eight segmented. Maxillary palpi 

 three segmented. Prothorax much longer than the head, without long 

 spines at hind angles (one present in S. cariahilis). Legs, especiall}'' 

 hind pair, quite slender. Wings either reduced or fully developed; 

 when present, the fore wing is broad at l^asal fourth, the remainder 

 being ver}" narrow; only one longitudinal vein developed; fore fringe 

 long; spines on veins numerous and moderatelj" developed. Abdomen 

 in some species strongly arched and its segments broad and short; tip 

 of abdomen conical in both sexes. Abdomen of male much more slen- 

 der throughout. 



Species of this genus leap readily. 



The characters of this genus are extended to include the following 



species: 



SYNOPSIS OF SPECIES. 



Body nearly black except segments four, five, and six of abdomen almost white; 



wings reduced cUigulatus (p. 141) 



Bddy yellow with brown or gray markings; wdngs present and with two spines on 



lahit fourth, where hind vein usually is ruriabilw (p. 143) 



SERICOTHRIPS CINGULATUS, new species. 

 Plate III, figs. 27-29. 



Female. — Length 1 mm. (0.84 to 1.25 mm.); width of mesothorax 

 0.25 mm. (0.22 to 0.31 mm.); width of abdomen 0.37 mm. (0.31 to 

 0.15 mm.). General color very dark brown; abdomen cross-banded 

 with white in the middle. 



