444 



now in process of rapid evolntion, probalily having heen a rela- 

 tively recent imniigrant to this Island. 



Ont of the 200 specimens, one individual has genal cones 

 a little shorter than the vertex but otherwise conforming to the 

 species. Some individuals were killed too soon after emer- 

 gence and 2:)arts of the exo-skeleton have shrunk, thus shorten- 

 ing the genal cones, but the one female referred to above was 

 not of this category. 



Trioza pnUata n. sp. 



This appears to be an incipient species derived from 

 T. lanaiensis, paralleling in its differentiation another species, 

 T. ohiacola, but evidently not directly related to the latter. 



In size of body similar to the average example of T. lanaiensis. 

 Color wholly black, or in spots dark brown ; thoracic dorsum conspicu- 

 ously reticulately marked, sparsely hairy. Genal cones about as long as 

 vertex, seldom shorter, divergent. Antennae twice as long as width of 

 head or sometimes less. Forewings clear, venation as in T. lanaiensis 

 except radius shorter. Female genitalia similar; male unknown. 



Distribution : — Island of Lanai — three females from Waio- 

 pao, November 29, 1916 (W. M. Giffard, on leaves of Cya- 

 thodes; six females from another part of the Island not desig- 

 nated, December, 1916, and February, 1917 (GifFard). 



The distinctive and constant characters of color, shorter 

 genal cones and antennae probably mark this off as a separate 

 species, though it is possible that a biologic study would show 

 it to be but a local or perhaps even seasonal variation. The 

 occurrence of some on Cyathodes does not indicate necessarily 

 a difference in food habits, though that is possible. 



Trioza liawaiiensis n. sp. 



Length of body 2.0 to 3.0 mm. ; length of forewing 2.8 to 3.9 mm. 

 General color about as in T. iolani ; front and middle tibiae on distal 

 third or half and all tarsi black or brown ; venter of abdomen blotched 

 with brown ; forewings clear. 



Closely resembling T. iolani in many ways but larger and stouter; 

 genal cones about as long as vertex, somewhat divergent, more pubes- 

 cent. Antennae 2 to 2^ times as long as width of head. Legs longer 

 and stouter; hind tibiae with a serrated callus at base. Forewings large, 



