443 



Trioza lanalerms n. sp. 



Length of body, male 1.5 to 2.2 mm.; female 1.7 to 3.0; length of 

 forewing 2.5 to 3.2. General color orange yellow to straw color, or 

 commonly reddish brown, usually with darker streaks on mesonotum, 

 and abdomen blotched with brown ventrad ; antennae darker on distal 

 half; tarsi dark; forewings usually clear but sometimes slightly milky 

 or faintly yellowed. Body surface sparsely clothed with soft pul)escence, 

 stiffer and longer on vertex and mesoscutum. 



Very similar in general to T. iolani, of which it appears to be a 

 derivative, differing in some characteristics, however. Genal cones longer 

 than vertex, sometimes one-quarter longer, acute, divergent, more hir- 

 sute. Antennae 2^ to 3 times as long as width of head. Legs stouter 

 and longer; hind tibiae usually with three, rarely four black spines at 

 apex. Forewings a little longer, clear or slightly milky ; veins with 

 smaller, scarcely visible setae, even the costal setae scarcely visible under 

 considerable magnification. Male forceps nearly as long as anal valve, 

 constricted near base and narrowed abruptly near apex into a narrower, 

 somewhat finger-like ending. Anal valve large, convex on posterior 

 margin, with broadest point at middle. Female genital segment as long 

 as abdomen or nearly so. 



Distribution : — Island of Lanai — 200 males and females 

 collected at varions points, Kaikolani, Kapano, and others, 

 at altitudes ranging from 1500 to 3400 ft., in December, 1916, 

 and January and Fel)ruary, 1917 (W. M. Giifard). ]\Iost of 

 these Avere taken on foliage of ohia lehua (Mefrosidcros spp. ), 

 which is probably the only regular food plant of the species. 



This appears to he an incipient, not yet clearly marked, 

 species developing from the Oahuan species, T. iolcnii. Thus 

 far it has not been found on any other island of the group, 

 hut it appears to be a very common one on this Island. 



In this species there is considerahle variation in size, but 

 none that in itself seems to mark off a distinct species. Ottt 

 of 200 specimens, about six are very large and seven very 

 small, hut between these there is almost every degree of varia- 

 tion so that it would be impracticable to designate either of 

 these extremes as distinct species, which one quite prol)ably 

 would do if the series which Mr. Giifard collected had not 

 been so extensive. It is quite possible tliat in time those vari- 

 ations will break the species into several distinct ones, for 

 along with size fluctuations are also fluctuations in size of 

 anatomical parts. It would appear that the species is right 



