1919.] New Zealand Institute Science Congress. 273 
health of the community, is also being carried out. Prior to this investiga¬ 
tion, only five species of mosquitoes had been recorded from the Dominion, 
one of these being known also in Australia. Recent observations show 
that we have a considerable number of forms, some of which occur in other 
parts of the world ; this feature tends to indicate that certain of these have 
been introduced, and shows the possibility of the yellow-fever species ( Stego - 
myia. fasciata) or of some of the malarial carriers (Anophilinae) becoming 
established, since the conditions in the northern portion of the Auckland 
district are favourable for their welfare. Of the four factors—the blood- 
parasite, man, certain Anopheline mosquitoes, and a favourable breeding- 
environment—necessary for the spread of malaria, we have three, particu¬ 
larly in the Auckland district. These are, the blood-parasite (in individuals 
who have contracted malaria in other countries), man, and favourable 
breeding conditions. Already indications of the malarial forms have been 
noticed in certain parts, a feature which is being carefully investigated^ 
The return of soldiers suffering from malaria increases the chances of this 
disease becoming established. 
Another problem awaiting the investigator is to be found in our aquatic 
insect fauna and its value as nourishment for fresh-water fish. The most 
prominent order of insects in this respect is the Neuroptera, of which 
about sixty-five species have been described from the Dominion, while of 
these some 76 per cent, are aquatic. In his work, New Zealand Neuroptera, 
G. V. Hudson has published some valuable information about their habits. 
An examination of the stomach contents of sixty trout showed a total of 
5,494 insects, of which about 87 per cent, were Neuroptera. 
As time goes on, new phases of entomology will continually present 
themselves ; for example, forest entomology will probably be an important 
aspect of the subject in the future, for when the areas now being placed 
under exotic timbers become more extensive the danger of insect-depredation 
will correspondingly increase. Those insects most liable to attack standing 
timbers are well represented in the indigenous fauna. The beetles are 
perhaps the most prominent in this respect, and we have in New Zealand, 
if we can rely upon the records, some 920 species of timber-boring forms 
and some eighty leaf-eaters. The larvae of moths are also an important 
feature, since their depredations at times may be responsible for the defolia¬ 
tion of the trees. On the other hand, every available method should be 
adopted to guard against the establishment of any exotic forms, some of 
which have already reached our shores, but, as yet are not sufficiently 
plentiful to cause any serious loss. 
For the benefit of those whose interests are at all influenced by insect 
problems an endeavour is being made to compile a work dealing with such 
destructive insects as occur in New Zealand, and with the best methods of 
control. Such a work, however, based of necessity upon the information at 
present available, will be merely of a temporary nature, the forerunner of a 
more complete and detailed publication resulting from extended research. 
In order to carry out this undertaking successfully, not only will the 
co-operation of the farming community be necessary, but also more investi¬ 
gators will have to enter the field, which is as yet practically untouched. 
This field, being so closely interwoven with out natural resources, calls for 
the ablest workers, since it is from the results of accurate investigation 
only that the factors controlling the influences detrimental or beneficial to 
man can be adjusted to suit his interests, and from which practical lessons 
may be drawn for demonstrating to him his responsibilities. 
21—Science. 
