The species is not an early one and the first outdoor captures were made June 30 and as late as September 9. Some collections have been recorded from New Brunswick, Little Ferry, Hackensack, and Great Piece Meadow. The species seems to confine itself to wooded areas exclusively and to prefer those which are low, swampy, and cold. None of the collections made indicate that it is at any time a house mosquito.
As to the matter of hibernation nothing is really known so far as I am aware. It is probable that the winter is passed in the egg stage and possible that the egg may become dry at times ; but none of the other species known to me as egg hibernates make so late a start in the spring as this species seems to do.
The egg laying habits have been observed by Dr. J. W. Dupree, of Baton Rouge, Louisiana, and recorded by Professor H. A. Morgan. A female specimen captured April 30 was permitted by Dr. Dupree to feed upon his hand until fully engorged. On the morning of May 1 forty eggs were found, some at the bottom of the glass containing the water, while others were resting upon some fibers of cotton which had accidentally fallen into the vessel. Dr. Dupree thinks it altogether likely that the eggs, which are deposited singly, under normal conditions rest upon floating debris.
Rather large or medium sized, black with deep purple sheen. Beak and legs black, hind legs heavily scaled, last two tarsal joints and part of preceding one white. Thorax with pale yellowish scales scattered over black background, abdomen unbanded. Very characteristic mosquito, recognized at glance by metallic purple sheen and white hind feet.
Altogether, while this species is sometimes common and bites hard, it can scarcely be considered a pestiferous species, because it does not leave the woods and breeds only in such swampy areas as are not often visited.
Measures 5-6 mm (.20-.24 inch) in length, exclusive of beak, which is about half length of body. Occiput densely covered with yellowish brown scales ; proboscis black, without bands ; palpi in female purplish black, rather slender, four- jointed, terminal joint minute and circular. In male palpi very long, three- jointed, longer than proboscis by two terminal joints; evenly dilated from tip of basal joint to apex; purplish, with white band in middle of basal joint, nearer base; apical two joints set with rather short hairs. Antennae dark brown in both sexes, basal joint of female yellowish.
Thorax brownish black, profusely sprinkled with creamy yellow scales, pleura dark brown with large irregular patch of grayish white scales. Femora largely yellowish, black toward apices on upper side, with white dot at knee. Tibiae and tarsal joints black with purple sheen, those of hind legs densely scaled, tibiae swollen at apex ; whole of last two tarsal joints and apex of middle joint white. Claws of male anterior and middle tarsal joints unequal, larger with curved, blunt median tooth and acute basal tooth, smaller with single tooth near base, posterior claws equal, each with single median tooth. Female claws equal on all feet, anterior and middle ones slightly sinuous, with median tooth nearer base, posterior like those of male.
Abdomen deep metallic purple above, yellowish beneath, yellow extending up sides at apex of segments, showing slightly on dorsal surface at apical angles in last two or three segments.
Full grown, measures 7-8 mm. (.28-.32 inch) in length, exclusive of anal siphon, body slate gray to blackish. Young and half grown specimens whitish to pale gray. Head large, slightly smaller than thorax, widest at eyes, a little excavated immediately before antennae, rounded in front ; pale yellow, usually immaculate, at times faint clouds, or distinct brown spot in center of vertex. Four hair tufts of two hairs each, in pairs widely apart, arise from central part of vertex, a larger one of five or six hairs at base of each antenna. Antenna very long and slender, sharply curved a little below middle and tapered evenly toward apex ; whitish at base, becoming brown apically; surface thickly set with broad spines of which bases prolonged, giving antenna scaled appearance; tuft situated on curve at middle, consists of six or eight hairs; apex has three long spines, one very short one and small joint. Rotary mouth brushes large, wholly composed of simple hair. Mentum broadly triangular with large apical tooth and thirteen to fifteen small ones on each side. Maxillary palpus normal with short, stout basal joint, mandible peculiar by deep indentation on dorsal surface, by reduction in size of one of curved dorsal spines and by having row of papillae in-stead of spines between large dorsal spines and teeth.
Thorax broader than long with lateral hair tufts short and wholly destitute of tufts on anterior margin.
First three abdominal segments transversely oblong, remainder subquadrate, each with two hairs to lateral tuft except in three anterior segments ; these with three or more. Eighth segment bears lateral combs ; scales composing them each with a long apical spine and short lateral ones attached to separate band, fringe-like, six or eight scales on each band, central ones large and long, lateral ones small and broad. Anal siphon very large, greatly dilated in center, tapering rather acutely toward apex ; each of lateral pectens have three or four spines, single spine slender, with broad base and number of long and short upright basal teeth, on one or both sides of main spine. In small larvae siphon proportionately much larger and paler. Ninth segment almost twice as broad as long, completely ringed by chitinized saddle ; fourteen or fifteen short tufts of ventral brush confined exclusively to ventral margin, each issuing from distinct pit, rather than barred area, which is present as mere rudiment at apex. Double dorsal tuft very small, anal gills long and slender, not over twice length of anal segment.
A collector describes the adult female as follows (the experience took place on the Great Piece Meadow about the middle of August):
"The persistence of this mosquito is almost incredible. When one invades it haunts, at first not a specimen may be seen ; but in a few minutes it seems as though every individual in the locality has concentrated on one's person. Brushing them away is a mere waste of time for they return to the attack with double fury, and their bite is very painful. So eager are they to insert their lancets that they can be very readily taken with vials, and in one hour I took 100 specimens in this way. Working pools for larvae, with both hands occupied, in a locality where they are present, is most unbearable, for with the hands wet their reluctance to leave is still greater and they may be crushed by simply laying the finger upon them. At one time a mosquito rested upon the back of my hand and before she got a hold I disturbed her by sliding my finger towards her; she rose hastily about four inches and immediately descended on the same spot ; nine times was this repeated, the insect each time rising four or five inches and alighting within half an inch of the same spot; the tenth time she moved about two inches and I let her get a good bite, then disturbed her in the same way. As fast as I could remove my finger she was back again and only lost heart at the nineteenth time when she flew on my clothing and was bottled."
The testimony of the other collectors is the same, and there is no doubt that this species shares with Aedes aurifer the first rank for persistence in the mosquito tribe.
"The eggs," according to Professor Morgan, "resemble somewhat in shape those of Aedes aegypti though larger. Short spines pointing toward the so-called head of the egg are uniformly distributed over the entire shell. The egg has a flat and a convex surface, and with the latter uppermost presents a distinctly fusiform shape. Unless debris or a strong film floats upon the surface of the water, all the eggs sink to the bottom of the vessel, which accounts, no doubt, for the irregular periods of incubation. Of the forty eggs deposited during the night of April 30, a few hatched on May 15, others hatched May 30, and still others of the same brood on June 10. It will be seen from this that a wide range obtains as to the period of incubation.
"The larvae are active at the surface of the water for the first twenty-four hours, after which they move to the bottom when disturbed and can remain there as long as forty-seven minutes without coming to the surface for air.
"The larvae are not 'wrigglers' in the true sense of the term. They jerk characteristically when suddenly disturbed, but ordinarily move from the top to the bottom of the vessel at an angle of about 45°, with little motion save the rapid movement of the oral cilia. The passing of the larvae from the top to the bottom of the water with apparently little effort gives them a graceful appearance. While at the bottom of the glass they catch large bundles of spirogyra, which are broken into smaller pieces as the surface is approached."
The earliest larva taken in New Jersey was at Hemlock Falls, June 20. It was next found in a large woodland pool with partly rocky bottom, on the Garret Mountain, near Paterson. On June 30 larvae were taken from the South Orange Mountain, from which adults were obtained July 2 and 3. On July 15 larvae occurred at the College Farm and near the old copper mines at Arlington. August 8 there was another brood at the College Farm, and on the fifteenth others were taken at Livingston Park. During this month the adults were found in the Great Piece Meadow, and during September large numbers of larvae in the woodland pools there and in the Troy Meadows. As late as September 30 the larvae were found in numbers, full grown and ready for the change. Pupation began October 1, and the first adult occurred October 4. Development during the summer is very rapid, but in late fall it becomes much slower.
Psorophora ferox is a medium-sized mosquito native to much of North and South America. It inhabits wet woodlands, laying its eggs in temporary pools filled with rainwater. Larvae develop during summer in North America. They are aggressive feeders and give painful bites.[1][2] The mosquito is reported to be active during both day and night.[3]
The adult's thorax is covered in dark scales with flecks of lighter yellowish scales. The abdomen is mostly dark-scaled dorsally, and yellowish ventrally. These yellowish scales form apicolateral triangular patches. The dorsum reflects a purple color. The legs are largely dark with white scales on the last two tarsal segments. The female's wings range from around 3.7-4.0 mm. The proboscis is long and dark.[1]
Ps. ferox occurs throughout the eastern United States and southeastern Canada, south through Mexico, Central and South America, and the Caribbean.[1]
Ps. ferox carries a number of diseases, although it is not considered a major vector. It is known to carry Venezuelan equine encephalitis virus (VEE). It was found to be a minor vector of West Nile virus (WNV) in New York. Several viruses have been found in this mosquito in the Amazon, such as Una virus and Ilheus virus. In Central and South America, the mosquito carries the larvae of Dermatobia hominis, the human bot fly, a parasite whose larvae develop inside the flesh of a mammal host.[2]
Psorophora ferox is a medium-sized mosquito native to much of North and South America. It inhabits wet woodlands, laying its eggs in temporary pools filled with rainwater. Larvae develop during summer in North America. They are aggressive feeders and give painful bites. The mosquito is reported to be active during both day and night.
