GENUS JANTHINOSOMA 339 1. J. Lutzii, Theob. Mesonotum with a broad median band of metallic pxirple, bordered by lateral stripes of brilliant yellow scales.
h. With the thorax undecorated. ' /8. With the last two hind tarsal joints white. 2. J. discrucians (Walker). Occiput, scutellum and bases of all the femora bright yellow.
y. With the last hind tarsal and apex of next white. 3. J. musica (Say). Hind femora yellow, fore and middle ones, with but little of that coloration, venter with triangular golden apical spots.
S. With the last hind tarsal joint only all white. 4. /. jyosticata (Wied.). With a yellow patch on the tergum of the second abdommal segment.
«. With a white band on the apical half of the fourth hind tarsal joint.
5. /. ArrihdlzagcB, sp. n. With only a narrow band of yellow coloration on the hind borders of the segments on the venter. B. With the hind tarsi entirely black.
6. J. oblita, Arribalzaga. The legs lighter coloured than in any other species ; pale yellow with testaceous articulations. 1. JANTHINOSOMA LUTZII, Theobald (Monog. I, p. 257). Plate xiii, fig. 7, Venation of ? wing.
Wings unspotted, dusky. Last t-wo joints of hind foot entirely white, but the tarsi otherv^'ise unhanded. Thorax conspicuously adorned by a broad, band of purely deep brown scales, separating large golden-scaled lateral areas. Abdomen deep chocolate-brown, with triangular, lateral bright ferruginous spots, not readily seen when viewed directly from above. Venter with segments deep chocolate at the base and ferruginous on their apical half.
Head black with a small yellow frontal tuft, and the middle of the vertex and nape bright yellow, but deep brown at each side, behind the eyes. Palpi, ? , very short, deep purple throughout. Those of male very dark ; longer than the proboscis by nearly the whole of their last two joints, which are sub -equal, and together much shorter than the very long thh-d joint. Pleurae and coxae marbled yellowish and white, bases of all the femora ferruginous below, but not perceptible as seen directly fx'om above. There are minute femoral knee spots to all three paii-s of legs, which are of a dark bronzy amethystine tint. Stem of anterior fork
340 GNATS OR MOSQUITOES — CHAPTER XIII less than one third the length of its cell. Halteres with pale stem and fuscous knob. Length. — 4 to 5 mm.
Habitat, — Itacoatiara, Lower Amazon, Rio de Janeiro, Trinidad, Aqua Santa.
Time of capture. — February (Amazon), December (Trinidad). Dr. Lutz writes : "It occurs in damp woods and shady river shores. It stings in the daytime. The larva is green. Common in Brazil." 2. JANTHINOSOMA DISCRQCIANS (Walker).
C. discrucians, Walker; " D. S. ;" p. 430; nee J. discrucians, Arribdl. Wings unspotted, dusky. Last two joints of the hind feet and apex of next white. Thorax dark grounded, clothed with scattered yellow scales. Abdomen deep brown, unhanded, but with yellow lateral spots on the hinder borders of the segments. Occiput, scutellum, and bases of all the femora also bright yellow. This is a good sized species, the wing length being about 4*4 nnn. With the exception of the small yellow points enumerated above, it is of a lustrous, violaceous deep brown almost throughout ; but the base of the venter is also yellow, and the two front abdominal segments show either as entirely yellowish, or with apical banding of that tint, according to the position of the insect. The armature of the long veins consists of truncate and of linear scales.
Head black ; the vertex and nape clothed with shox't, falciform, golden scales, and erect forked ones of the same colour. Scales of identical form and colour as the former clothe the mesonotum. Palpi of J very dark and short ; those of (J much longer than the proboscis, and nearly black throughout. The fore and mid legs have a varying amount of dark coloration at the apices of the femora, but those of the hind are golden-yellow throughout ; elsewhere the legs are deep purple. Pleurae and coxae marbled whitish.
Habitat. — South America ; Argentina, San Paolo, Brazil. Note. — The above is a description of Walker's type, supplemented by fresh specimens sent by Dr. Lutz, but Mr. Theobald points out that this cannot be Arribalzaga's species, as he clearly figures it with a single white band only on the hind tarsus, the last joint of which is shown as black.
3. JANTHINOSOMA MUSICA (Say) (Jour. Acad. Nat. Sci. Phil, vi, p. 149).
= C. Mcxicanus, Bellardi.
Wings unspotted, very dusky. Last two hind tarsal joints and apex of next, wholly white, but tarsi otherwise uniformly dark violaceous purple. Thorax, violet-black-grounded, unadorned, nude but for some scattered golden scales. Abdomen deep
GENUS JANTHINOSOMA 341 amethystine and black, dorsally unadorned, but the segments beautifully marked on the venter with golden triangular apical spots and amethystine basal areas.
A beautifully brilliant insect when in good condition, which may at once be known by its long, thick-scaled, hind legs, with white tarsi as desci-ibed.
Head with sooty ground colour clothed with deep golden ferruginous short falciform scales, and erect forked ones of a somewhat deeper shade. Palpi, ? , short, deep purple at apex, with a golden tinge at the base. Antennee dusky. Legs with all the femora pollen yellow at the base, most extensively so on the hind pair ; the joints from the tibia downwards greatly enhanced in apparent breadth by a dense covering of long scales. Length. — 4*8 to 5 mm.
Habitat. — Eio de Janeiro; British Guiana; Indiana; South Amazon. Time of capture. — Eio de Janeiro, November (Moreira). Observations. — This seems to be an abundant South American species, which Dr. Lutz calls the Big Wood Mosquito. It stings, says Dr. Lutz, in the daytime.
4. JANTHINOSOMA POSTICATA (Wied.) (" A. Z. I." p. 9). Wings unspotted, dusky. Tarsi uniformly dark bronzy, except the last joint of hind legs, v^fhich is entirely white. Thorax dark brown, unadorned, but clothed with short falciform, golden scales. Abdomen deep chocolate-brown, unhanded, but adorned with an ill-defined triangular golden spot on the tergum of the second, and with large, triangular lateral spots on the hinder borders of each segment, which latter, however, are scarcely noticeable viewed directly from above, venter entirely yellow but for a row of small, triangular dark basal spots. 5 . — Head black groimded, with forked scales and short falciform scales alike of a golden tint. Antennae fuscous, about half the length of proboscis. Palpi very short, of a uniformly dark metaUic purple. Pleurae marbled with white and golden ; femora yellow beneath, but seen from above are but little paler at base than at apex ; there are no knee-spots beyond a faint paling of their apices. The tibisE, especially of the hind legs, appear apically dilated owing to their dense covering of long scales. Halteres with pale stem and fuscous knob. Length. — 5 mm.
Habitat. — Castries, St. Lucia ; Argentma.
5. JANTHINOSOMA ARRIBALZAGiE, Sp. n.
Janthinosoma discrtccians, Arribal. (" L. A." p. 53). Plate xiu, fig. 2a, Venation of wing, ? ; 2b, Tarsus of hind leg. Wings unspotted, densely black-scaled ; unusually wide in proportion to their length. Tarsi uniformly black- SXialed, with
34'2 GNATS OR MOSQUITOES — CHAPTER XIII <he exception of a broad basal white band on the fourth joint of the hind legs. Thorax sooty, clothed on the mesonotum and scutellum, with short falciform, golden scales with numerous long stiff black bristles on their margins. Abdomen, deep amethystine jDurple, with triangular apical golden spots on each segment, and some yellow scales and hairs along the hind border of the first ; ventrally, the segments show triangular golden apical markings. There can be little doubt that it was upon this species that Arribalzaga founded his new genus, as it agrees entirely with his description, given below, while specimens, sent to Mr. Theobald by Dr. Lutz, and which correspond to Walker's type of C. discrucians, though believed by the latter naturalist to be Arribalzaga's species, were at once seen to fail to correspond with Arribalzaga's description and figure, and it is obviously unlikely that the discrepancies can be due to careless drawing. This difficulty is now set at rest by a specimen I have just received from Dr. Lutz, labelled " JantJiinosonia, sp. n.," and which was at once recognised by Mr. Theobald as the missing species.
The head and appendages almost black, the vertex and nape clothed with erect forked, and short falciform golden scales. The pleurae and coxae show extensive areas of golden scales and the lower surfaces of the femora, and the base also above of those of the hind legs, are bright golden, the apices of the femora showing also a barely noticeable yellow knee-spot.
This sj)ecies can be easily distinguished froin any other of the genus by the single band on the hind tarsi.
Original description : — " ( ? and ^). — Blackish, somewhat steely. Head clothed behind and below with pale golden scales ; anteimae fuscous ; proboscis dark steely ; palpi of the 3" much longer than the proboscis, with an apical brush ; those of the J dark steely with the last joint large and oblong. Thorax with dark fawn-coloured scales above, with greyish-golden scales below and on either side. Wings limpid with fuscous scales, which are densely arranged in front and more sparsely behind ; first sub-marginal cell longer and narrower than the second posterior, their stenas nearly equal, but while that of the first sub-marginal is barely half the length of the ceE, the stem of the second posterior is quite as long as its cell. Legs dark steely, but with the femora broadly pale yellowish at the base; hind tarsi with the base of the fourth joint adorned with a pale yellow band. Abdomen steel-coloured above, the first segment with broad silvery fringes, the remainder not fringed but golden on either side ; the venter with pale golden arcs. Length. — 6 mm.
''Habitat. — South America (Walker) ; Argentina (Arribalzaga)." 6. JANTHINOSOMA OBLITA, Arribalzaga (" L. A." p. 54). Wings unspotted ; tarsi without obvious bands ; thorax unadorned, dark grey ; abdomen undescribed, but presumably unhanded. Nothing resembling this has come to hand.
GENUS PSOROPHORA 343 Original description : — " $ — Hoary or dark cinereous, with scanty frosty cinereous scales. The first twelve joints of the antennae with the bases pale and slender, and the apices thickened and piceous, all with not very dense pale fuscous plumes; the last two jomts fuscous; eyes black ; proboscis pale testaceous, witli the base and apex dusky ; palpi longer than the proboscis ; the two basal joints short and piceous, the remaining two pale yellow, with scanty villosity ; the last wanting. Legs pale yellow, with the joints indistinctly testaceous ; tibiae longer than the first tarsal joint ; the anterior and middle tarsal claws are wanting, but the hinder are long, the external over twice as long as the inner one, with a very long additional tooth beneath ; wings hyalhae, shghtly yellow, the veins clothed sparsely with long slender fuscous scales ; first sub-margmal cell twice as long as its stem, the second posterior of the same length as its stem. Length. — 4*50 mm. " Habitat. — Navarro, in Argentina."
aenus VII. PSOROPHORA, R. Desvoidj (" Essai," p. 412 ; " L. A." p. 38).
The genus Psorophora was constituted by E. Desvoidy in 1827, and it is difficult to understand why the generic value of so distinct a type should have been denied by all subsequent entomologists, until the genus was revived by Arribalzaga in 1891.
Though not so shaggy as Mucidus, it may be fairly said to belong to what may be called the hirsute genera of Mosquitoes, but the wings are not brindled in the same way as is the case in that genus, and the scales of their veins are like those of Culex and Stegomyia.
Owing probably to the defective character of the lenses available at that date, Desvoidy was led to give as the leading character of his new genus, the presence of peculiar scale-like structures, which he thought he made out, overlying and protecting the prothoracic stigmata. As a matter of fact, nothing of the sort is to be found in these gnats, and the supposed operculum is really nothing more than a tuft of scales covering the shoulder callosities.
In many respects they may be said to be intermediate between Miicidus and PmiopUtes, the legs and general appearance being much as in the former, while the arrangement of the scales on the head and thorax resembles that in the latter genus, though there are some stiff linear scales just at the juncture of the nape with the neck. The ? palpi too, though certainly proportionally
344 GNATS OR MOSQUITOES — CHAPTER XIII longer than in Panojdites and Culex, being fully one-third a=i long as the proboscis, are shorter than Mucidiis, where they are about half its length. In the ^ the palps are exceptionally long and strongly tufted. Arribalzaga describes the $ palp as 5-jointed, but personally, I can make out but two joints in addition to the short basal piece, though it is possible that the minute bead-like terminal joint which he figures, may have been broken off, as the specimen I examined was badly rubbed. The posterior transverse vein is placed just internal to the middle, instead of being outside it, as in Mucidus.
A fair short definition would be : Mosquitoes with shaggy legs, but with smoothly scaled nape and mesonotum ; the males with the palpi longer than, and the females with theirs, about one-third the length of the proboscis ; with marked humeral callosities, and the posterior venule internal to the middle venule.
All the three known species are from the warmer parts of the American continent.
Mr. Theobald's modified definition runs as follows : — " Head covered with small broad curved scales and upright forked ones; meso-thorax with curved scales in the middle with short broad scales laterally ; abdomen with small flat spatulate scales ; antennae rather short m both sexes, in the ^ the two last joints elongated as in Culex ; palpi short in the ? , long in the $ , twice as long as the proboscis in the ^ , five-jointed, the first two jomts very small, the third nearly as long as the proboscis, slightly enlarged apically ; the fourth and fifth joints thick, the two nearly eqiialling the third in length ; in the 5 the palpi are also five-jointed, but short, never more than one-half the length of the proboscis ; the first and fifth joints are very small, the third longer than the second, the fourth longer than the third, according to' Desvoidy and Arribalzaga, but I cannot detect the small basal and apical joints myself in either species. The proboscis is short and rather thick. The prothoracic lobes are said to have lateral appendages which protect the stigmata of that segment. Wings with the scales rather long and thin ; first sub-marginal cell short, only a little longer than the second posterior cell ; the posterior cross-vein close to the mid crossvein, but always a little nearer the base of the wing than the mid. Legs with the apices of the femora, tibiae, and to some extent the first tarsals with long scales ; ungues of the ? all equal, thick, with a large distinct tooth to each, in the ^ fore and mid claws unequal, the larger one twice as long as the smaller and with two teeth, the smaller with one tooth ; hind claws equal and single toothed." He tabulates the three members of the genus as below : — Fuscous, clothed with yellowish and pale scales (7-8 mm.) 1 C iliata {Fahricius).
GENUS PSOEOPHORA 345 Fuscous, clothed with dark scales, black in general appearance 2 Holm herfjii, Arribalzaga. Fuscous, clothed with brown scales, apices of hind femora white, very densely scaled 3 scintaHans, Walker.
1. PSOROPHORA CILIATA (Fabr).
C. ciliatics, Fabr. ; C. violestus, W'ied, ; P.S. Boscii, R. Desv. ; C. pe^-terrena. Walker ; C. conterreus, Walker.
(Ent. Syst. iv, p. 401 [1794], Fabr. ; Syst. Antl. p. 38 [1804], Fabr. [= Culex ciliatics] ; Dipt. Exoti. p, 36 [1821], Wied. ; Auss. Zwei. Ins. i, 3, 5 [1828] Wied. ; Dipt. Exoti. p. 11, Sup. iv. [1838], Macq. ; Dipt. Brit. Mus. i, p. 2 [1848], Wlk. ; Ins. Saund. p. 431, Wlk. [= C. ■perterrens] ; Dipt. N. Amer. Cat. 18, Osteu-Sacken ; Dipt. Arg. Rev. d. 1. Mus. d. 1. Plata, p. 40 [1891], Arri.)
Wings unspotted. The three distal tarsal joints with yellowish basal bands. Thorax yellowish-white, with median and lateral fuscous lines, the armature consisting of large overlapping scales, as also is that of the abdomen, which both dorsally and ventrally is almost pure white. Legs testaceous, tafted at the joints. This is one of the largest species in the family, the abdomen ( $ ) being over 6 mm. long, and the wing nearly 8 mm. The entire insect has a rich red-brown ground colour, covered with nearly white scales ; the proboscis and palps being, however, darker, their scales being mixed yellow and fuscous. Those of the ? are exactly one -third the length of the proboscis, while in the ^ , they are nearly twice as long. The legs are deep brown above, and on the whole of the first two tarsal joints. There is a dark median nude line on the nape.
Habitat. — Texas, Atlantic coast of Southern states of America, Georgia, Honduras, Argentine Republic, Brazil. Its bite is said to be unusually painful.
2. PSOROPHORA HOLMBERGII, Arribalzaga ( ' L. A. ' p. 40). Closely resembles the preceding, being nearly as large, and differing only in being of a much darker colour, the body scales being dark grey, instead of yellowish-white, and in its wanting the dark naked line on the nape ; but though necessarily less prominent, the thoracic adornment is essentially the same. The coxae too are pitch-brown instead of having almost snowy tufts of scales. The legs are almost black, and the tarsal banding of the fore legs very indistinct, while on the mid legs, the upper two, and on the hind, the upper four tarsal joints have silvery basal bands.
Habitat. — Brazil, and Argentine republic.
346 GNATS OR MOSQUITOES — CHAPTER XIII 3. PSOROPHORA SCINTILLANS (Walker).
Sabethes scintillans, Walker (" Journ. Proc. Linn. Soc." III. [1859], p. 77). Wings unspotted. Tarsal joints with basal white bands. Thorax dark brown, with a median and two lateral snowy lines. Abdomen black, segments with or without snowy apical patches. Proboscis curved as in Megarhina.
This species was originally described as Sabethes by Walker, but is certainly a Psorophora.
Head black, clothed with small flat white scales, black erect ones and numerous black bristles. Palpi of ^ live jointed, nearly twice as long as the proboscis, dark metalhc purple and blue. Thorax black, with dusky brown curved hair-hke scales in the middle and flat white spindle-shaped ones at the sides. Abdomen black, with brown scales with bright violet-blue reflections, first two segments velvety brown, the apical one tinged with metallic green, sometimes with white apical lateral patches. Legs black, with dense long dusky scales with purple and brassy, &c., reflections, apices of hind femora white, tarsi not so densely scaled as the femora and tibise, except the first joints of the hind legs. Wings dusky yellowish-brown. Ungues of the $ equal, very stout with an accessory claw beneath. Length. — 6-5 to 8 mm. <? ; 7 to 9 mm. ? .
Habitat. — Amazon Ptegion.
Genus VIII. MUCIDUS, Theobald (Monog. I, p. 268). This new genus has been established by Mr. Theobald, for the accommodation of the curious group of species allied to Psorophora, the peculiarities of which were first pointed out in the First Edition of this Handbook (p. 181), one which was partially described under the suggested name of Ps. Scataphagoides. They are large hirsute insects which look much more like dung flies than they resemble ordinary gnats. The wings, and, in fact, the entire insect is in all of them elaborately brindled and banded with intermixed fulvous, dark brown and white scales, the tufts of scales on the legs lending a curious dentate appearance to their margins. In all of them, too, the internal fringe of the wing is made up of brilliantly contrasted dark and light lengths. They appear to be confined to the Old World and Australia, just as Psorophora is, so far as we at present know, purely American. Mr. Theobald defines the genus as follows : — " Head clothed with narrow curved, forked, upright, and long, twisted scales.
" Thorax with narrow curved scales and long twisted, apically expandedscales, as in the head.