80 BULLETIN 85, UNITED STATES NATIONAL MUSEUM. 



and thorax. The young take from four to five weeka to mature, and breed throughout 

 the summer. 



The fall brood probably lay their eggs in the crevices of the bark and twigs. These 

 hatch at the first appearance of spring and feed on the tender new shoots and leaves, 

 and are those found fully matured by the first or second week in April. 



The larva is fringed on the margins with long hairs, as in other 

 species of Trioza. 



TRIOZA MEXICANA Crawford. 

 Figs. 210, 340, 389, 531. 



Trioza mexicana Crawford 'lla:439. 



Length of body (female) 2.6 mm; length of forewing 3.6; 's\ddth 

 of head 0.87. General color reddish brown, usually dark, occasionally 

 lighter; head lighter than thorax; antennae whitish on basal third, 

 remainder black. Vertex and notum slightly pubescent. 



Head not as broad as thorax; vertex more than half as long as 

 broad, with a very shallow depression on each side of median line, 

 rounded down in front toward genal cones; cones nearly or fully as 

 long as vertex, rather slender, acute, not very divergent, ibitennge 

 about one and a half times as long as width of head, slender. 



Thorax strongly arched, punctate, pubescent slightly. Pronotum 

 long. Hind tibiae with three apical spines within. Wings dusky, 

 membrane covered entirely with fine punctural dots; veins set with 

 a double row of setae; less than two and a half times as long as broad, 

 broadly rounded at apex. 



Genitalia. — Male. — ^Anal valve large, long, front margin straight, 

 hind margin very arcuately rounded caudad, apex short; forceps long, 

 sides subparallel except subapically, apex abruptly broadened, black. 

 Female. — Genital segment almost as long as rest of abdomen; dorsal 

 valve longer than ventral, both slender and acuminate in apical 

 portion, margin slightly serrate. 



Described from several males and females collected on a species of 

 Rhus in the mountains near Cuernavaca, Mexico, altitude 10,000 feet 

 (Crawford). 



Type in author's collection. 



TRIOZA MEXICANA MINUTA Crawford. 



Body distinctly smaller than in the species. Head similar. Pro- 

 notum comparatively shorter. Wings smaller, less dusky; setae on 

 veins smaller and less promment; venational characters similar. 

 Genitalia similar, smaller in male. 



Described from three females and one male from Oaxaca, Mexico 

 (Crawford), no other data. 



Type in author's collection. 



