DESCRIPTION. 9 



dark brown. Spines upon segments 2 to 5 arc of medium size, but not very con- 

 spicuous. Color of head varying from gray-brown to yellow-brown. 



Prothorax about five-ninths as long as broad and slightly longer than the 

 head; sides rounded, slightly wider at hind than at fore angles; one stout spine 

 at each anterior, and two stouter spines of equal size at each posterior angle; 

 anterior marginal pair of spines about one-half as long as those at front angles ; 

 usual row of five spines on each side of hind margin, of which number 4 is 

 equal in strength to those on the front margin. Mcsothorax nearly one and 

 one-third times as wide as the prothorax, broadest posteriorly, sides curving 

 outward; mesonotum without conspicuous spines, posterior margin forming an 

 obtuse angle in middle. Metathorax slightly narrower than mesothorax, sides 

 nearly parallel, broader than prothorax at posterior edge; metanotum b< 

 two pairs of spines at front edge, the inner pair being as strong as those at 

 front angles of prothorax. Wings present (probably reduced at some season of 

 year), average length about 0.68 mm., not reaching to the tip of the abdomen, 

 breadth equal to about one-thirteenth of their length ; fore wing has two longi- 

 tudinal veins, each bearing stout spines set at regular intervals ; fore wings 

 shaded ash gray, hind wings gray only along basal three-fourths of midvein ; 

 spines on wing veins dark brown and conspicuous ; costa bears 19 to 24 spines : 

 fore vein, 13 to 18 ; hind vein, 10 to 12 ; scale, 5 ; interior of scale, 1 ; fringe of 

 hairs on costa of fore wing quite heavy, in length exceeding the breadth of the 

 wing. Legs of medium length, lighter than body in color, pale yellow, shaded 

 more or less with "brown on upper side at middle of femora and tibia?; a pair 

 of stout brown spines at inside of tip of each tibia, small brown spines scat- 

 tered along femora and tibia?; spines standing in two rows on inner side of 

 hind tibiae are weak and only about four in each row. 



Abdomen nearly cylindrical to eighth segment, then tapering abruptly t»> an 

 acute tip; color uniformly dark brown; a still darker-colored narrow chitinous 

 thickening extends across dorsal side of segments 2 to 8 near anterior edge. 

 Three or four quite stout and rather conspicuous dark-brown spines stand at 

 each side of dorsal plates on 2 to 8 ; six rather prominent spines stand in a 

 row on posterior edge of ventral plates 2 to 7 ; terminal spines stout and 

 prominent; tenth segment split open along dorsal median line. 



Described from 10 females. 



Male specimens of this species have not been found. 



Three cotypes (three slides) deposited in the D. S. National Museum. 

 Type No. 8134, U.S.N. M. Three cotypes (three slides) deposited at the Massa- 

 chusetts Agricultural College. Four cotypes (two slides) retained. 



Habitat. — Quincy, Fla. ; Nacogdoches, Tex.; Climax. 6a. 



Wingless females appear in May and seem to predominate by the 

 latter part of that month. 



This species may be readily distinguished from Euthrips tritici 

 Fitch by its color, which is brown, that of tritici being yellow. Dif- 

 ferences in structure by which the species may be readily separated 

 are found in the postocular spines, those of nicotiaruB being weak and 

 inconspicuous, while those of tritici are quite prominent. On the 

 wings prominent differences are found in the number of spines on 

 the veins, the costa of nicotiana bearing from L9 to 24, the fore vein 

 13 to 18, and the hind vein 10 to L2, while in tritici the costa bears 

 from 26 to 28, the fore vein 20 to 22, and the hind vein L5 to IS. 



Egg.- -The eggs are deposited in the tissues of the stem and leaves. 



I. ami. first stage. — Length abort o.l\"> nun.; width of mesothorax 0.11 mm. 

 24372— No. ()5— 07 u 2 



