As waste-disposal arrangements improved and coconut husks were gathered together and destroyed as breeding places, the population of the Armigeres pest was curtailed to some extent. Significant numbers of these insects still remained, as breeding persisted in husks and rotting stumps concealed in the jungle surrounding the Station.

Armigeres lacuum Edwards, 1922.

Larvae were generally found in coconut husks containing copra in an advanced state of decomposition. Frequently they were collected from water of a high organic content in the rotting stumps of small trees, more rarely from tin cans, and once from clear water in an aircraft tyre lying in thick grass at the edge of a jungle clearing. When the water in husks was not of too high an organic content, Aëdes albolineatus and Aëdes scutellaris were sometimes found in association.

Larvae answered closely to the diagram and description of Armigeres milnensis published by Lee (1944), apart from the fact that the number and arrangement of hairs in the lateral comb were more variable in Armigeres lacuum.

Under laboratory conditions the length of the larval stage varied between two and three weeks, and that of the pupal stage between two and four days. The males of any particular batch were observed to emerge some hours before the females; and the sex representation in a batch was approximately equal.

* Armigeres breinli (Taylor, 1914).

Breeding places of this insect were much as for the preceding species. Of very similar habits to Armigeres lacuum, it was much less common throughout the period under discussion.

Culex (Lutzia) halifaxi Theobald, 1903.

From August to October, larvae were dipped from clear water in grassy wheel-ruts about the whole area. A few specimens were collected from an uncovered water tank.

Frequently these predatory and cannibalistic larvae appeared in pools already occupied by other mosquitoes, notably Anopheles p. moluccensis, Culex fraudatrix and C. pullus. In such cases a noticeable decrease in the populations of these other species soon became apparent. Even in the presence of many larvae of other species, a C. halifaxi larva would not hesitate to attack one of its own kind when the opportunity was available.

The mosquito spent upwards of two weeks in the larval state, under laboratory conditions. The average duration of the pupal stage was two days.

Imagines were rarely encountered in the field, and were never observed to bite.

*Culex (Lophoceratomyia) cylindricus Theobald, 1903.

Aquatic stages were found during the whole period under review. Never very common, they were dipped from wheel-ruts of long standing, grassed-over ditches, swampy places, and on one occasion from a shallow well. Anopheles p. moluccensis, Culex fraudatrix and C. pullus frequented the same types of breeding place as this species.

Culex (Lophoceratomyia) fraudatrix Theobald, 1905.

This was a rather common mosquito at Jacquinot, Bay. Its larvae were collected from wheel-ruts, grassed-over drainage ditches, swampy areas, native wells and tree holes.

Associated with it were:—in wheel ruts: Anopheles p. moluccensis, Culex halifaxi, C. cylindricus and C. pullus; in drainage ditches: Anopheles p. moluccensis and Culex cylindricus; and in Pandanus swamp: Anopheles p. moluccensis, Bironella gracilis, Uranotaenia albescens and Culex pullus.

Imagines were occasionally encountered biting near breeding areas in the daytime. At the beginning of October one was taken at the light in the laboratory, just after nightfall.

*Culex (Culiciomyia) papuensis (Taylor, 1914).

At the close of August a few larvae were located in clear water in a small wheel-rut with marginal and emergent vegetation. About two months later a concentration of larvae up to third instars was found in clear water in a truck tyre that lay at the edge of the camp clearing.

Associated mosquitoes were:—in the wheel rut: Anopheles p. moluccensis and Culex pullus; in the tyre: Megarhinus inornatus and Aëdes scutellaris.

Culex (Culiciomyia) pullus Theobald, 1905.

This was by far the commonest species of the genus Culex at Palmalmal. It was abundant during the whole period of the survey. Breeding usually took place in clear water exposed to direct sunlight. Temporary pools of the kind preferred by Anopheles p. punctulatus were often utilized. Developmental stages were rarely found in artificial containers.

Associated mosquito species were:—in road ruts of a temporary nature: Anopheles p. punctulatus and Uranotaenia quadrimaculata; in road ruts of long standing: Anopheles p. moluccensis, Culex halifaxi, C. cylindricus, C. fraudatrix, C. papuensis, C. annulirostris and Culex sp. nov.?; in a stream backwater: Uranotaenia albescens; in shallow swamps: Anopheles p. moluccensis, Bironella gracilis, Uranotaenia albescens and Culex fraudatrix; and in the tray of an abandoned truck: Aëdes scutellaris.

C. pullus adults occasionally entered huts during the day and early evening, but did not prove troublesome.

*Culex (Culex) annulirostris Skuse, 1889.

Larvae were collected twice only. Early in August the species was found in clear water in a long-established road rut, in company with Anopheles p. moluccensis and Culex pullus. A 44-gallon drum filled with rain water yielded a few more larvae in the middle of September.

Imagines were occasionally collected in lighted huts during the evening.