Culex pervigilans Bergroth.
Culex pervigilans Bergroth, Wiener entom. Zeitung, 1889, p. 295.
—— Theobald, Mono. Culic. of the World, vol. 2, pp. 88–90.
—— Miller, N.Z. Dept. of Health Bull. No. 3, 1920.
—— Edwards, Synopsis of Mosquitoes of Australasian Region (1924) p. 124.
General Coloration.—Thorax dark brown, densely covered with golden scales arranged longitudinally; traces of two curved longitudinal lines, especially when denuded of scales and bristles. Abdomen black, with white basal bands; venter white-scaled. Legs black, white spots at knee joints of femora. Ungues of female small, simple and much curved; of the male, uniserrated in fore and mid legs, in the hind, simple.
Female (Fig. 25). Head: Nape and occiput covered with golden-yellow curved scales; numerous black upturned curved bristles at the margins. Proboscis dark brown, darker at apex, lighter at base, strongly haired and scaled. Length 2 ½ mm. Palpi (Fig. 26) dark brown, 4-jointed, thick in appearance; penultimate joint curved inwardly, as long as next two, heavily scaled and bristly; in length one-
fifth of proboscis; basal joint almost black in some specimens. Antennae dark brown, almost black. Eyes deep purplish-black: strong black bristles around margins.
Thorax dark brown, covered with golden-yellow scales arranged in longitudinal rows; numerous black bristles about the median and marginal areas. Scutellum light brown, narrow curved scales and 8 border bristles. Metanotum dark brown. Pleura dark brown.
Pleural pilotaxy (Fig. 27) as follows: Protergum carrying 3 to 8 pronotal bristles. Pro-episternum has three prosternal bristles. Pro-epimeron carries 2 to 4 (usually 3) strong pro-epimeral bristles covering and guarding the first spiracle; numerous golden sickle-shaped hairs anterior to these. Spiracular area bare. Mesepisternum carries 3 to 6 pre-alar bristles, 6 to 10 sternopleural bristles on the posterior margin arranged vertically. Many white scales are present
on the area between the pre-alar and sternopleural bristles. Mesepimeron has 4 upper mesepirmeral bristles covering and guarding second spiracle; below these is a patch of white scales; one lower mesepimeral bristle. Coxa pale brown, with black bristles and odd white scales.
Legs dark brown, in parts almost black, heavily scaled and bristled. Femur dark brown dorsally, light brown ventrally, bristled, knee spot almost white. Tibia with pale knee joint, more heavily bristled than femora and slightly longer. Tarsus darker brown than the other joints. Ungues equal, simple, much curved, but showing a strong raised swelling basally. (Fig. 28).
Wings (Fig. 29) 4.5 mm. in length; when folded back longer than abdomen; densely clothed along the veins with brown scales.
Cell R.2 (first marginal cell) longer and narrower than cell M.2 (second posterior cell), its base more proximal than the base of the latter, its stem short, almost one-fifth the length of cell, shorter than stem of M.2, which is a little more than one-third the length of cell. Supernumerary and mid cross veins slightly separate, about half their own length away from each other. Posterior cross vein longer
Fig. 29.—Wing of C. pervigilans.
Fig. 30.—Lateral scale of wing vein.
Fig. 31.—Median vein scale.
Fig. 32.—Fringe scale of wing.
than mid cross vein and twice its own length distant proximally from it. Lateral scales (Fig. 30) of medium width, tapered distally; median scales (Fig. 31) broader, rounded distally; fringe scales (Fig. 32) scimitar-shaped. Halteres with light brown stem, knob darker in colour and a black patch on each side. Length 5.6 mm.
Male: Antennae lighter in colour than in female; the penultimate and antepenultimate joints longer, hairs brown in colour. Proboscis darker than in female, sometimes pale in centre. Palpi much longer than proboscis, last two joints with stiff black hairs.
Hypopygium (Fig. 33) large and composed of many appendages, the dorsal surface of the sub-apical lobe covered with numerous strong bristles pointing out to external border. The sub-apical lobe has a leaf-like appendage lying across from internal border to external border; it overlies the base of a strong stiff curved bristle which springs from the inner margin of the sub-apical lobe and points upwards and outwards. On the external border of this lobe are three chitinous tapered appendages turned backwards towards the phallosome. The claspers are long, “goose-necked,” and carry a narrow pointed claspette. Harpago and harpaginal fold can be seen by reference to the figure. Ungues of male fore-leg (Fig. 34) unequal, curved, proximally there is a small acute recurved spur; at the middle length is a longer blunt appendage. The fifth tarsal joint is heavily bristled and scaled; its base is expanded to form a strongly curved and acutely pointed projection.
Length, 6 mm.
Habitat, New Zealand; it is not yet certainly known elsewhere.
This is the common domestic mosquito in New Zealand. It is found in both Islands wherever there are human habitations, climatic conditions being no deterrent to its breeding; it is found from the sea coast to the inland mountains. It is purely a nocturnal feeder. There is no definite seasonal occurrence; it is found in abundance one
week, apparently disappears for a while, and then suddenly and unaccountably reappears. It breeds through the whole of the winter in Auckland city and suburbs, and as far south as Mercer, residents of which parts are pestered with its painful bites throughout the whole of the year. Some do, however, shelter for a while in the coldest weather in cellars, stoves, pig pens, stables and buildings, lying quietly close up to the walls with the legs widely spread. Directly a warm spell ensues they leave their shelter and begin to breed.
The numbers of the adults are kept in check by birds, lizards, dragon-flies and spiders, the latter continuing their activity among those sheltering within doors. In workshops and cellars I have seen spiders catching these mosquitoes resting on window panes.
Culex pervigilans notifies its presence by a high-pitched flying note, higher and much louder than that of A. notoscriptus. described above. Its persistent and annoying hoverings are very characteristic, and are by many regarded as more troublesome than its moderately painful bite. Graziers aver that cattle are seriously troubled at night by its attacks, and this is a matter which I hope to investigate.