186 Philippine Journal of Science 1919 
Genus T&IOZA Foerster 
Trioza is a very large genus of which many of the species are 
difficult to distinguish. It appears to be a group in which very 
active evolution of new species is in progress, especially in the 
North Temperate Zone. In the Tropics and the South Tempe- 
rate Zone it is much less numerously represented, most of the 
triozine species there being in other genera, chiefly Megatrio za 
with its armed hind tibise. With Cecidotrioza Kieffer I am un- 
familiar. Whether or not it is truly distinct from Trioza or 
Megatrioza is not yet clear. 
Key to the species. 
a'. Hind wings normally developed, at least half as long as forewings. 
6‘. Forewings more or less colored, not wholly clear. 
c 1 . Dorsum and vertex hairy; forewings thickened and darkened on 
basal third, remainder glassy. 
d 1 . Forewings nearly three times as long as broad; media and 
cubitus each forking beyond its midpoint. (Japan.) 
T. (Trichochermes) bioclor Kuwayama (’10: 54). 
cf. Forewings two and one-half times as long as broad; media and 
cubitus each forking at or near its midpoint, making the mar- 
ginal cells relatively longer. (Philippines.) 
T. divisa Crawford (T7: 172). 
c 1 . Dorsum and vertex not hairy. 
dt. Forewings somewhat coriaceous, dull opaline in color, about 
two and one-half times as long as broad. (Tasmania.) 
T. tasmaniensis Froggatt (’03: 329). 
d*. Forewings semitransparent, somewhat browned, about four times 
as long as broad. (Tasmania.) 
T. dobsoni Froggatt (’03: 331). 
if. Forewings not colored, glass clear or sometimes very slightly yellowed 
or smoky. 
c*. Forewings broadly rounded at apex, not angular nor acutely pointed, 
less than three times as long as broad. 
d l . Genal cones distinctly shorter than vertex. 
e l . Forewings nearly three times as long as broad; antennas long; 
forming galls on Eucalyptus. 
f. Legs short, stbut; genal cones with long hairs. (Australia.) 
T. orbiculata Froggatt (’01: 274). 
f. Legs long and slender; genal cones less hairy. (Australia.) 
T. eucalypti Froggatt (’01: 277). 
e". Forewings not more than two and one-half times as long as 
broad; antennas rather short. 
p. Body light green; genal cones very short; curling foliage of 
Olearus. (Tasmania.) T. olearias Froggatt (’03: 332). 
f. Brown to almost black; genal cones one-half to two-thirds as 
long as vertex; forming galls on Metrosideros. (Hawaii.) 
T. ohiacola Crawford (’18: 442). 
cf. Genal cones as long as vertex or sometimes longer. 
