Mosquitoes in Melanesia — Belkin 
223 
It is, therefore, excluded from the caledonica 
complex. 
In the material of the caledonica complex 
available to me there appear to be several 
ecospecies, ecotypes, ecophenotypes and geo- 
graphical races, clearly marked in the larval 
stage but generally without striking differences 
in the male genitalia, adult coloration or in 
the pupal stage. The larval characters of three 
of these forms are so constant and uniform 
that I consider these three as distinct species: 
caledonica , from Nepenthes pitchers in New 
Caledonia; folicola , from leaf axils of various 
plants in Espiritu Santo, New Hebrides; and 
rotumana , from Rotuma Is., north of Fiji. 
Aside from these stabilized segregates, the 
caledonica complex consists of a multitude of 
larval forms utilizing a variety of breeding 
habitats from "palm-bracts” and tree holes to 
bamboo, coconut shells and artificial con- 
tainers in the New Hebrides, Loyalties and 
New Caledonia and adjacent islands. All of 
these I consider, at the present time, members 
of a highly plastic, polymorphic, actively 
evolving species, T. melanesiensis. As discussed 
under this species, there appear to be included 
in this assemblage at least two major geo- 
graphical races and a bewildering array of 
ecological and minor geographical races in 
various stages of evolution towards distinct 
species, a condition fully attained by caledon- 
ica , folicola and rotumana . In view of the ab- 
sence of controlled progeny rearings and 
crossbreeding experiments, it may be argued 
that a simpler interpretation of all these differ- 
ent larval types would be that the entire 
caledonica complex is one highly plastic spe- 
cies with a multitude of ecophenotypes. While 
it is true that some mosquito species show 
considerable modifications correlated with 
different larval habitats, as for example the 
length of the siphon and of the anal gills, 
particularly in brackish and fresh water, none 
of these modifications are as distinct, constant 
or numerous as in caledonica , folicola or rotu- 
mana. Furthermore sympatric, as well as allo- 
i patric, ecological speciation seems to be the 
rule in mosquitoes utilizing small collections 
of water in living plants or dead plant material 
as breeding sites, as for example in the Aedes 
kochi complex in the Solomons and in the 
genus Wyeomyia in the Neotropical region. 
A large number of such ecospecies are species- 
specific in regard to the host plants while 
others may have a wide range of hosts. The 
main difference between speciation in these 
taxa and that found in the caledonica complex 
is that in the former the diagnostic larval 
characters are often accompanied, and some- 
times exceeded, by genitalic characters in the 
male and color characters in both sexes in the 
adult stage. In the genus Tripteroides several 
groups of otherwise quite distinct species 
exhibit no noticeable differences in male gen- 
italia as in the case of the caledonica complex. 
Similarly several other groups in this genus 
are also characterized by a uniform drab color- 
ation in the adult stage. 
Zoogeography 
The zoogeographic relations of the cale- 
donica complex are of considerable interest. 
The nearest unmistakable relative is T. tas- 
maniensis from Tasmania and the eastern part 
of New South Wales. Other than this there 
is no close similarity between this complex 
and any of the other species of Tripteroides in 
the surrounding areas. The one species found 
in New Zealand, T. argyropa (Walker, 1848), 
is so distinct that it has been placed in the 
monotypic subgenus, Maorigoeldia , which is 
probably worthy of full generic rank. To the 
east, only the Fijian T. purpurata (Edwards, 
1921) is known and it is undoubtedly a mem- 
ber of the subgenus Tripteroides , showing 
affinities with T. distigma (Edwards, 1925) of 
the Solomons. In the Solomons nothing even 
remotely resembling the caledonica complex 
has been recognized. The next closest rela- 
tives of the complex are found in the second 
group of the caledonica section, represented 
in Australia by collessi Lee, 1946 from Upper 
Baron, North Queensland and in the Solo- 
mons by the aberrant coheni Belkin, 1950. The 
