PLATE X.
1, An. cinereus, Theob. ; 2, An. gigas, sp. n. ; 3, An. funestus, Giles ; i, An. Listoni, sp. n. ; 5, An. Bhodesiensis, Theob. ; 6, An. punctipennis, Say.; 7, An. mininms, Theoh. (diagrammatic); 8, An. Lindesayii, Giles; 9, An. atratipes, Skuse ; 10, An. maculipennis, Meig. (detailed figure within an outline to show variation of size). Follow I'ltUe IX.
PLATE XL 1, An. bifurcatus, L. ; 2, An. Walkerl, Theob. ; 3, An. nigripes, Stseger ; 4, An. Theobaldi, sp. n. ; 5, (a) wing scales of An. Sinensis, (b) of .in. barbirostris, (c) of An. Rossii, (d) of An. costalis ; 6, Cijclolep2)feyon Graohomii, Theob.: 7, Sabefhes remipes (Wied.); 8, Sab. loncfipes, (Pabr.) ; 9, Toxoynchites brevipalpis, Theob. ; 10, Eretmapodites quinquevittatus, Theob. ; 11, Janthinosovia mnsica, Theob.
Folloiv Plate X.
333 CHAPTER. XIII.
The Culicina Sub-family.
This is at once the typical, and bj"- far the largest group of the Culicida, the type genus, Culex, including nearly 150 species.
In all, the female palpi are markedly shorter than the proboscis, while those of the male are at the least not much shorter, and may greatly exceed it in length.
Some genera, however, distinctly approach the MegarhinincB and AnoplielincB even in the length of the ? palps, as these are nearly half as long as the proboscis in Mucidus, and in Psorophora, are fully a third of its length.
In the typical genera, as in Culex and Stegomyia, they are, however, very short and take the form of a mere pair of blunt projections on each side of the base of the proboscis. The male palpi vary so greatly in relative length and form that no general description of them is possible. Another character that all have in common is that the anterior fork cell is at least as long as the hind one.
The males are easily distinguished from those of the Anophelina by the fact that they are never clubbed, at any rate in the same way as those of the Anopheles.
One or two species, notably E. spathipalpis (Eond.), have the $ palps clubbed, but even in these cases the organ is not carried in the same way ; as those of the Anophelina are held close against the proboscis as far as the commencement of the club and then diverge sharply from it at an angle of about 45° ; but are kept straight or nearly so, and never habitually lie along the proboscis, being kept rather away from it, generally arched upwards in a graceful curve.
It is, however, on the other hand, by no means so easy to distinguish the females from those of the jSSdomina, and here we can rely only on the more detailed, generic characters of the arrangement of the scales and bristles, especially those of the head and of the various regions of the dorsum of the thorax.
334 GNATS Oil MOSQUITOES — CHAPTER XIII The small, but well-defined genus, Janthinosoma, resembles the Megarhinina in many respects, having the same fine metallic lustre, and the same may be said to some extent of Armigeres, which is certainly very closely allied to Janthinosoma, having the same long male palps and the same tendency to ornamentation of the venter, while the terga of the abdominal segments are quite dark. Psorophora and Mucidus form a very natural group of shaggy insects that look more like flies than gnats to a casual glance.
All these aberrant genera that are thus more or less intermediate between the type genera are chai-acterised by possessing shaggy legs, and in uninjured males, EretmajMclites, the scales covering them are enormously elongated to form flat, paddleshaped expansions.
Most of these aberrant Mosquitoes are forest insects, and these peculiar structures probably give them some sort of protective resemblance to parts of the plants and flowers frequented by them ; but this is a mere guess, as we know as yet very little of the habits and life history of these forms. The genera Stegomyia and Armigeres form another very well defined group, characterised by the smooth curved line of their heads, and a strong tendency to elaborate decoration of the mesonotum with white lines on a jet-black ground. PanoiMtes and Tceniorhynclms again are closely allied, while Deinokerides may or may not be one of the Aedomina, as no males have yet come to hand.
Owing to the separation of new genera, and the consequent modification of the definitions of those already established, the definitions of all are somewhat changed from those quoted in the first edition of this handbook, and as it would occupy much space to enter into any critical disquisition on the newer as contrasted with the older landmarks, it will be understood that those given below follow entirely the classification adopted by Mr. Theobald in the British Museum monograph which is concurrently passing through the press. This tabulation of the genera of the sub-family runs as follows : — 7. Palpi short in ? , long in <? ; 1st sub-marginal cell as long or longer than the 2nd posterior cell sub-family Culicina 77. Legs more or less densely scaled.
Posterior cross-vein nearer the base than the mid cross-vein; hind legs with tarsi in ^ densely long scaled ; wing scales long and rather thick Genus V. Eretmapodites
THE CULICINA SUB-FAMILY 336 Cross-vein as in Culex ; scales of crown and occiput broadly spindle-shaped ; 3rd long vein continuedasdistinctpseudo-veinintothebasalcell Genus VI. Janthinosoma Posterior cross-vein nearer base of wing than mid cross- vein ; wings with thin scales Genus VII. Psoropliora Posterior cross-vein nearer apex of wing than mid cross-vein ; wings with large pyriform parti-coloured scales Genus VIII. Mucidus 777. Legs uniformly clothed with flat scales. Scales of the wings very large, flat, broad, asymmetrical Genus IX. Panoplites Scales of wings dense, lateral ones large, elongated oval or lanceolate Genus X. Tceniorhynchus Metanotum nude, scales of wings much as in Tceniorhynclius, metanotum with a tuft of chetae and with patches of flat scales Genus XI. Trichoprosopmi 5. Head and scutellar scales all flat and broad. Wings with small scales, both spatulate and linear ; 3rd long vein not continued into basal cell Genus XII. Stegomyia Third long vein continued as an incrassation into the basal cell Genus XIII. Arm.igeres 85. Nape clothed with mixed narrow, curved, and upright forked scales, with small lateral patches of flat scales.
1. Second antennal joint small or moderate sized. Scales of the wings small, lateral ones linear Genus XIV. Culex 2. Second antennal joint very long, distal joints without scales Genus XV. DeinoTterides 3. Second antennal joint very long, 2nd to 5th joints clothed with scales Genus XVI. BracJdomyia Genus V. ERETMAPODITES, Theobald (Monog. p. 280).
This genus has been instituted by Mr. Theobald for the reception of a peculiar species, bred out by Mr. Austen from larvae found at Sierra Leone in old tins containing rain water. It presents some resemblance to Sabethes in having the hind feet provided with a peculiar paddle-shaped expansion formed of long scales, but it is only the males that ai'e so furnished, and even in them, the scales are so deciduous that they are often wanting even in fresh specimens.
336 GNATS OR MOSQUITOES — CHAPTER XIII Beyond the fact that it must obviously be a domestic species, nothing is known of its life history. The venation is essentially that of a Culcx, and the arrangement of the scales of the head and scutellum is that of Stegojnyia, to which genus it is perhaps most nearly allied. He defines the genus as follows : — "Head clothed with flat and upright forked scales ; antennae of the 5 fourteen-jointed, of the ^ fifteen-jointed, the last two joints long ; palpi of ? four-jointed, of the ^ long and thin, five-jointed, basal joint small ; third and fourth joints nearly equal ; apical joint about two-thirds the length of the penultimate joint ; palpi pointed, no hair tufts. Mesothorax clothed with narrow curved hair-like scales ; scutellum with flat scales on the mid lobe. Abdomen densely scaled with broad flat scales. Fore and mid ungues of ? equal, and each with a small tooth ; fore ungues of ^ unequal, the larger thick, simple, the smaller one thin, and with a single tooth; mid ungues unequal, the larger one stout, the smaller very thin, both untoothed ; hind ones equal and simple, small. Last two tarsi of the hind legs in the ^ densely scaled, forming a distinct ' paddle.' Wings with the first sub-marginal cell longer and narrower than the second posterior cell, stem of the latter considerably longer than the cell ; venation practically as in Culex. " A single species only occurs so far. The chief distinguishing features, besides the squamate structure, are the hairy posterior tarsi in the ^ , and the long thin hairless palpi and the ungues.
" Nothing is known of its life-history, except that Mr. Austen bred the gnats from larvae in old tins and bottles full of water. There is no continuation of the third vein as a pseudo-vein into the basal cell, as in Armigeres."
1. ERETMAPODITES QUINQUEYITTATUS, Theob.
(Monog. I, p. 280).
Plate xi, fig. 10a, Venation of wing; 10b, Scales from wing; 10c, " Paddle " of the <? hind leg.
Thorax bright ferruginous brown, with six golden-scaled lines, dividing five darker ferruginous lines. Abdomen black, the last two segments with brilliant silvery-metaUic scales, five lateral silvery-white patches. Legs black, with a white knee spot, pale bases to the femora, and with the hind tarsi in the ^ densely scaled, forming a dark broad paddle. Wings transparent, with dark brown scales.
5 . — Head densely scaled with brilliant burnished silvery scales, and with black upright forked scales behind; clypeus, palpi and proboscis black ; palpi of moderate size, thickly scaled ; antennae dark brown, with narrow pale bands ; basal joint black, with a few small ochraceous scales ; second joint testaceous, with black and ochraceous scales.
GENUS JANTHINOSOMA 337 (? . — Head as in the 2 ; proboscis long, thiii, black ; palpi not as long as the proboscis, black, with purple, and sometmies bronzy reflections, very thin ; penultimate and antepenultimate joints about equal ; the apical joint two-thu-ds the length of the penultimate, second short, first very small ; the apical joint ends in one long and several smaller bristles. Antennae banded with broad grey bands and narrow pale brown ones, basal joint black ; plumes deep brown, last two joints brown. Fore ungues unequal, one very thick, untoothed, the smaller one thin and serrated ; mid unequal, neither toothed, the large one very broad; hind equal, small, simple. Length. — 5"5 mm. Habitat. — Sierra Leone (September). Old Calabar (Annett). 2. ERETMAPODITES (?) ARGYROPUS (Walker).
Vide Uranotcania argxjropoda.
It is possible tliat Walker's G. argxjropus should be referred to this genus ; but for the sake of uniformity I follow Mr. Theobald in placing its description under the genus Uranotoema. Genus VI. JANTHINOSOMA, Arribalzaga (modified).
This is a small but very natural group of South American gnats originally separated from Culex by Arribalzaga, whose definition, however, seems to miss their real common points of peculiarity, and to insist too much on others that are really found in many other Culicina. They are of moderate size, and, seen at a little distance, are very sombre-looking insects, such decoration as they possess being almost confined to their ventral aspects, so that one would hardly suspect that Sabethes and Megarhina were their nearest relatives. On closer examination, however, it will be found that their dark-toned scaly covering glows with the same brilliant metallic tints as is the case in those genera, and that the scales of the legs, though not disposed in any specially eccentric fashion as in Sabethes, are really very long and dense. The thorax is clothed with broad falciform scales, much like those of the same region in Megarhina, and exactly similar scales take the place of the narrow curved scales of Culex on the head, though here they are mixed with erect forked scales, so that the covering of this region is essentially that of a Culex. They may be defined as follows. Janthinosoma. CulicidcB with the <? antenna considerably longer than the proboscis, but very short in the J . The abdomen and legs clothed with scales, deeply coloured, but having 22
338 GNATS OR MOSQUITOES — CHAPTER XIII a distinct metallic lustre. Thorax, including scutellum, clothed with short falciform scales. Head generally as in Culex, but with the narrow curved scales of that genus replaced by broader ones exactly like those of the thorax.
Wing scales much as in Culex. Fore ungues with an additional tooth in both sexes, those of the ? being large and stout. Arribalzaga gives as characters, which are found to hold good in all the members of the genus with which we are so far acquainted, the following : — Palpi of ? short, with the fourth joint subcorneal, and the fifth oblong and longer and thicker than the fourth. Those of the <? , much as in his Tceniorhynchus, but thinner and less hirsute, obviously longer than the proboscis and somewhat swollen towards the apex, the first and second joints minute ; the third very long, nearly three-fourths the length of the proboscis ; fourth and fifth subequal and together a little shorter than the third ; the fifth oblong and tapering. He adds that the branches of the anterior fork cell are twice as long as the fork stem, but this is not literally the case even in the type species, /. discrucians, and certainly does not hold good with all, though the stem is always much shorter than the cell.
All show a more or less distinct, nude inward extension of III, beyond the transverse veins, a character which they share with Armigeres, and, it may be added, with certain members of most other genera. To that genus, indeed, they present a strong general resemblance, especially in coloration, but the scales of the head differ, being arranged as in Stegomyia, in Armigeres, which wants also the metallic lustre of Janthinosoma. In all but /. ohlita (Arribal.), which I have not seen, as nothing resembling it has made its appearance at the British Museum, and the description of which reads more like that of Q>n Armigeres, all have a portion of the hind tarsi alone pale, and the extent and position of this is alone suflncient to distinguish between the six species with which we are at present acquainted. All appear to be sylvan insects, and one or two are said to be very vicious and troublesome.
Table of Species of Janthinosoma.
A. With some portion of the hind tarsi white.
a. With the thorax decorated.
)3. With the last two hind tarsal joints all white and a little of apex of next.