436 Pomona College Journal of Extomologv 



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

 to that of T. longistylus; dorsal plate somewhat longer than ventral ; sheaili 

 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 Oa.xaca, Me.x., 

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



This species is very closely related to T. longistylus and T. collaris Crawford. 

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

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

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

 in respect to genitalia to the Mexican form. 



Trioza nicaraguensis Cravvf. 

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



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

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

 lemon yellow ; antennae black apically. Insect small. 



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

 as broad as thorax. I'osterior 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. Antennae 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 ; prcepisterum large, subtrapezoidal ; epimeron al- 

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

 roimded 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 abdomen ; 

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

 one-third as long as dorsal plate ; both 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, by C. F. 

 Baker. 



Trioza frontalis sulcata (Crawf.) 

 (Syn. Trioza sulcata Crawford.) 

 In genera! this varietal form is very similar to the species. Although 

 coloration is but su])crficial and seldom a true varietal cliaracter, yet this 



