﻿SOLOMON ISLANDS TRIPTEROIDES — BELKIN 255 



subgenus in the adult stage and into a different subgenus on the basis 

 of larval characters. Lee (1946) redefined the subgenera to correct 

 this. It would appear that his groupings are natural ones, but, of 

 course, one would expect to find some overlapping between characters 

 of subgenera. The present species is one of these links and indicates 

 the close resemblance of members of the subgenera Rachisoura and 

 Mimeteomyia. As our knowledge of the genus Tripteroides is still very 

 fragmentaiy and many forms are still unknown in the larval stage, 

 the author prefers to assign coheni to the subgenus Mimeteomyia for 

 the present. 



T. coheni could be confused only with argenteiventris and atra in the 

 adult stage. It differs in the possession of a pair of anterior dorso- 

 central bristles, which are absent in the other two species. Female 

 argenteiventris are also distinguished by the short palpi, about one- 

 tenth of the proboscis. Other members of the caledonica-gvo\x^ are 

 strikingly different from coheni. T. tasmaniensis (Strickland) has 

 white-tipped femora and tibiae and pale hind tarsi ; caledonica (Ed- 

 wards) and rotumana (Edwards) have the pleural scaling restricted 

 to longitudinal stripes ; and collesii Lee has the venter banded with 

 dark scales. 



The larva of coheni is very distinct from any other previously de- 

 scribed species of the genus. Especially characteristic is the single 

 ventral hair arising on each side from the saddle of the anal segment. 

 No other species of THpteroides is known with the ventral brush re- 

 duced to less than two branches or arising from the saddle. 



Variation. — ^There is little departure from the type description in 

 the six specimens from Guadalcanal. Specimens from the eastern 

 tip of New Georgia and from Sterling Island in the Treasury Islands 

 also conform very well with the types. 



Specimens examined: 4 individual rearings, 8 adults, 6 larvae, 4 

 pupae. 



Biology. — The larvae of this species were collected only twice in the 

 course of the mosquito survey of Guadalcanal. One collection was 

 made in the hollow stump of a tree recently cut and containing clear 

 water with an odor of fermenting material. The other collection, in 

 the same locality, came from a tree hole with turbid water. Both 

 collections were made in second growth jungle surrounding a small 

 river. Very few larvae were obtained, and no other mosquitoes were 

 associated with this species. Eepeated searches for additional mate- 

 rial in the same locality failed to reveal this species. No adults were 

 collected. 



In the laboratory, the larvae exhibited the behavior characteristic 

 of other species of Tripteroides in that the greater portion of the 

 time they rested on their backs on the bottom of the rearing containers. 



