436 Pomona College Journal of Entomology 



longer on anal valve. Female. — Genital segment and ovipositor very similar 

 to that of T. loiigistyliis; dorsal plate somewhat longer than ventral ; sheath 

 and style together fully one-fourth as long as rest of body. Pubescence brief 

 and sparse. 



Described from three females and four males collected at Oaxaca, j\lex., 

 and two females at Orizaba, Me.x. , coll. D. L. Crawford. 



This species is very closely related to T. longistyliis and T. colhiris Crawford. 

 The principal and most constant variation between these three species lies in 

 the dorsulum, facial cones, and female genitalia. In all probability the male 

 of the two United States species, still unknown, will prove to be very similar 

 in respect to genitalia to the Mexican form. 



Trioza nicaraguensis Crawf. 

 (Fig. 152, T; 154, F; 155, K) 



Length of body 1.7 mm.; length of forewing 2.o mm.; greatest width .8 

 mm.; width of vertex between eyes .36 mm.; with eyes .56 mm. General color 

 lemon yellow ; antennse black apically. Insect small. 



Head moderately deflexed, quite coarsely punctate, with eyes not quite 

 as broad as thorax. Posterior margin of vertex arcuate, scarcely elevated 

 narrowly ; vertex not raised plate-like ; discal area with a fovea on each side 

 midway between median suture and posterior ocellar region; without a de- 

 pression or sulcus, or if present very slight ; lobately produced cephalad over 

 anterior ocellus, scarcely emarginate at median suture. Facial cones ratner 

 short, acute, moderately divergent, more so in distal half than in basal, sub- 

 vertical, very slightly and inconspicuously pubescent. Antennic slender, in- 

 serted at base of facial cones below produced vertex laterad. Eyes com- 

 paratively appressed, not as prominently bulging as usual. Labrum small. 



Thorax not large, arched but not strongly so. Pronotum short, depressed 

 below head and dorsulum ; proepisterum large, subtrapezoidal ; epimeron al- 

 most invisible ; fore cox;e large, mostly visible. Dorsulum quite acutely 

 rounded cephalad, slightly overhanging pronotum. Wings small, slender, deli- 

 cate, hyaline, about three times as long as broad, broadest across first mar- 

 ginal cell, subacute apically ; radius not as long as second cubital ; marginal 

 cells subequal ; venation yellowish, not conspicuous. 



Female. — Genital segment quite large, almost as long as rest of aiidomen ; 

 dorsal plate smaller; both plates about equal in length: genital pore large about 

 one-third as long as dorsal plate ; Ijoth plates produced caudad into a short 

 ovipositor sheath; sheath and style not quite as long as rest of genital segment. 

 Pubescence .sparse and brief. 



Described from one female collected in San Marcos, Nicaragua, liy C. F. 

 Baker. 



Trioza frontalis sulcata (Crawf.) 

 (Syn. Trioza sulcata Crawford.) 



In genera! this varietal form is very similar to the species, .\hhougli 

 coloration is but su])c'rticial and seldom a true varietal character, vet this 



