NO. 1310. NORTH AMERICAN THYSANOPTERA— HINDS. 191 



Food J)] a)) t. — Mullein . 



Uahitat. — Ames, Iowa; Amherst. Massacliusetts. 



Genus TRICHOTHRIPS Uzel. 



Head about as broad as long, Inoadly rounded in front. Eyes 

 small. Ocelli present in both these species, but often wanting-. ]\Iouth 

 cone not longer than its breadth at base; labrum pointed at tip. Fore 

 femora somewhat enlarged and tarsi armed witli a tooth. Wings 

 usually wanting, but present in both these species, slender throughout. 

 Abdomen very broad and heavy; tube very slender in proportion to 

 width of abdomen: no scale at base of tube in the male. 



The two species which I have placed in this genus may ])e distin- 

 guished bv the following characters: 



Tube fully as long as the head beacJii (p. 192) 



Tube two-thirds as long as the head uinhitus (p. 191) 



TRICHOTHRIPS AMBITUS, new species. 



Plate VIII, figs. 81, 82. 



Female. — Length 2 mm.; width of mesothorax 0A5 mm. General 

 color brownish yellow shading to brown or reddish brown. 



Head slightly longer than wide, widest just behind the eyes, rounded 

 in front; cheeks straight and converging posteriori}"; at hind edge 

 only six-sevenths the diameter at widest part; frons slightly elevated 

 between bases of antennte; post-ocular bristles present; a few scat- 

 tering small spines upon head not raised upon warts; surface faintly 

 reticulated. Anterior half of head light brown flecked with reddish, 

 posterior half fading to j^ellow at the neck. Eyes small, finely gran- 

 ulated, compact, not pilose, purplish by transmitted light, reddish 

 orange by reflected light; ocelli present, subapproximate, pale yellow 

 niai'gined inwardly with reddish brown crescents. Mouth cone reach- 

 ing nearly to posterior edge of prosternum; maxillary palpi two seg- 

 mented; labial palpi short and thick; labiimi broad and rounded; 

 maxilla? converging abruptly below the palpi and short. Antenna? 

 one and three-fourths times as long as the head, eight segmented, 

 though the joint between seven and eight is very indistinct; relative 

 lengths of segments as follows: 



12 18 28 20 21 20 15 8 



Segment one truncate, conical; two constricted toward base into a 

 broad stalk, cut off squareh^ at end; three to seven slenderly stalked 

 at bases; three to six clavate; seven cylindrical -ovate, very closely 

 united by full width of end to eight which is conical. Color of one 

 pale brownish j^ellow; two and three clear yellow; four 3'ellow at base 



