Summary

Mr. Graham's investigation has disclosed the following interesting points.

Aedes antipodeus lays its eggs in mud, in which they survive even when it dries, until rain falls and development is enabled to proceed.

The effect of salinity of the water is to hasten the maturity of the pupae of Culex pervigilans. When two parts of sea-water were added to one part of fresh water containing 50 pupae, all the pupae changed to adults within 24 hours.

The endemic forest species, Rachionotomyia argyropus, was found breeding only in water tanks in the Waitakere Hills. The larvae possess anal gills as well as a siphon, so are able to remain below the surface of the water. Apparently its undiscovered breeding places are deep pools and streams.

Culex pervigilans, which may be termed Auckland's mosquito enemy No 1, is characterized by its wide variety of breeding places and the length of its breeding season.

Several species of New Zealand mosquitoes inflict bites that are irritating to most people and cause loss of sleep, and two of them, Culex fatigans and Aedes notoscriptus, cause very painful bites which may result in severe inflammation and occasionally in serious illness.

The two mosquitoes which are intolerable nuisances in Auckland city and suburbs are the native Culex pervigilans, the night-biter, and the introduced Aedes notoscriptus, the dayime biter.

One disease-bearing species, Culex fatigans, was found only in and about Auckland and Whangarei, but has also been reported from Nelson. II was probably introduced from overseas and is now established here. This mosquito can transmit filariasis (common in Fiji and Samoa), but not malaria or yellow fever.

With the exception of Culex fatigans and of a few Anopheles maculipennis (a vector of malaria) found in the holds of two ships from Singapore and Samarang respectively, no evidence was found of any mosquito capable of transmitting disease.