Urano taenia in Solomon Islands — B elkin 
379 
Variation 
Uranotaenia quadrimaculata adults vary a 
great deal in size and to a lesser extent in 
coloration. On Guadalcanal all individuals 
originating from taro show a conspicuous 
dark diagonal band running in line from the 
dark spot on ppn across the subspiracular area, 
upper middle part of stp, and lower middle 
part of mesopleuron just above the lower 
mesepimeral bristle. An indication of this dark 
integumentary band is present in specimens 
from other breeding places, but it is never 
conspicuous. I cannot find any structural 
characters to differentiate this ecological race 
either in the adults or in the immature stages. 
The variation in the chaetotaxy of immature 
stages is shown in Tables 1 and 2. Although 
at first glance the variation does not seem to 
be great, actually it is much greater than in 
any species of mosquito I have studied, par- 
ticularly in the larva. Not only the branching 
but also the degree of development of individ- 
ual hairs varies a great deal. The position of 
smaller hairs is not as constant as it is in other 
species. There are cases of duplication of hairs 
in the larva. In the pupa there may be two 
extra pairs of hairs on the metanotum, prob- 
ably representing larval hairs 3, 5-T; on the 
abdomen, hair 11 is frequently present on 
segments III-V, and there may be a duplica- 
tion of hair 12 on these segments as well. 
One pupal specimen shows larval hair 9 re- 
tained on the left side of segment V. These 
anomalies have proved to be useful in estab- 
lishing the homologies of the larval and pupal 
hairs. They may prove to be of value also 
when the potentialities of the mosquito chae- 
totaxy and its pattern as tools in genetics are 
realized. 
The material from the other islands shows 
no variations that are not found on Guadal- 
canal, and there appear to be no characters 
on which geographical subspecies or races 
can be recognized within the Solomons. 
Specimens examined: 288M; 310F; 96P; 
866L. Individual rearings: 15 larval. 
Taxonomic Discussion 
Uranotaenia quadrimaculata is very closely 
related to U. nigerrima Taylor, 1914, from New 
Guinea. The two species are distinguished 
from all other Uranotaenia by the four dark 
integumentary spots, one each on the scutum 
in front of the wing root and the ppn. As 
pointed out by Edwards (1929: 314), U. quad- 
rimaculata differs from U. nigerrima by the 
generally lighter thoracic integument, includ- 
ing the four dark spots, and the absence of a 
patch of broad white scales on the side of the 
scutum immediately above the anterior end 
of the ppn. Instead of the conspicuous broad 
white scales in this area as in U. nigerrima, in 
U. quadrimaculata there are a few elongate 
light-brown or cream-colored scales. The other 
characters mentioned by Edwards also hold 
but are difficult to determine because of con- 
siderable variation. Knight, Bohart, and Bo- 
hart (1944: 15) confused this distinction in 
their key by assigning to U. quadrimaculata 
the patch of broad, whitish scales which is 
characteristic of U. nigerrima. The remaining 
characters were properly assigned to the re- 
spective species. As a result of this confusion 
of characters Knight, Bohart, and Bohart {loc. 
cit.) referred specimens from the Solomons, 
New Britain, and New Guinea to both species. 
I have examined 23 adults of this group from 
several localities on New Guinea. They are 
all U. nigerrima. All the Solomons specimens 
are definitely U. quadrimaculata. The two spe- 
cies are allopatric, and there is no overlap 
whatever. 
The larva of U. quadrimaculata is extremely 
close to U. nigerrima. The chief differences 
appear to be in the greater development in 
U. quadrimaculata of the following thoracic 
hairs: 4-P 3b (2-4) instead of 1, 2b; 7-P 2-4b 
instead of 1; 7-T 3, 2b(l-5) instead of 1, 2f. 
U. nigerrima has the comb scales with distinct 
basal spicules whereas these are never strong- 
ly developed in U. quadrimaculata. U. niger- 
rima also has more prominent basal spicules 
on the pecten teeth and strong apicolateral 
spicules on the anal saddle. 
