Pomona College Journal of I'^ntomology 423 



Synopsis of the Genera of Triozinae 



A. Radius longer than basal portion of subcosla. 

 B. Facial cones (as cones) entirely wanting or sub-obsolete. 

 C. Vertex very deeply eniarginate anteriorly at median suture, with the 

 antennae attached to the projecting rostra. Facial cones entirely 

 wanting. 

 D. P)i-rostrate appearance of head very marked; emargination very deep. 

 Third antennal segment not very thick midway, sometimes some- 

 what enlarged. Rhinopsylla Riley 

 UD. Bi-rostrate appearance of head not so conspicuous, emargination 

 deep but less than above. Third antennal segment very much en- 

 larged and thickened midway, thicker than succeeding segments 

 and almost as thick as preceding. Bactericera Puton. 

 CC. Vertex not deeply emarginate anteriorly, without the peculiar bi- 

 rostrate appearance. Facial cones sub-obsolete, with merely globose 

 projections at insertion of antennae. Bpitrioaa Crawford. 

 BB. Facial cones (as cones) not entirely wanting. 

 C. Pronotum long, quite flat, not depressed below dorsuluni and head ; 

 dorsulum not strongly arched. Allotrioca Crawford. 

 CC. Pronotum short, arched and distinctly descending cephalad ; distinctly 

 depressed below dorsulum and head; dorsulum quite strongly arched. 

 D. Facial cones exceedingly short and small, scarcely projecting beyond 

 vertex ; labrum easily visible from in front ; antennse inserted on 

 f rons and base of facial cones ; vertex distinctly raised plate-like, 

 and ustially conspicuously colored ; margin of vertex colored differ- 

 ently from discal portion. Anal valve of male genitalia bilo- 

 bate; claspers not acute at apex. Paratrioza Crawford. 

 DD. Facial cones at least moderately long, or not exceedingly short ; 

 labrum not visible from in front. 

 E. Thorax broader than entire width of head including eyes. Facial 

 cones normal, usually moderately long, rather acutely rounded 

 apically, more or less divergent. Trioza Forster. 



(Petalolyma Scott) 



EE. Thorax distinctly narrower than entire width of head including 



eyes. Facial cones long, very slender and acute, closely appressed 



and not divergent in the least. Neotrioza Crawford. 



AA. Radius shorter than basal portion of subcosta ; discoidal portion of 



subcosta almost wanting. Ceropsylla Riley. 



General Revised Synopsis of the Genus Trioza 



A. Forewings not entirely hyaline ; with more or less dark banding. 



B. Subcosta bordered with dark band ; radius straight, shorter than second 



cubital ; first furcal two-thirds as long as third ; genital segment of 



female very short ; anal valve of male obtriangular. with large 



posterior lobe. T. californica Crawf. 



