Art. XI.—On Two Blepharocerids from New Zealand.
[Read before the Wellington Philosophical Society, 1st May, 1912.]
Among the insects presented to the Zoological Museum at Cambridge by Mr. G. V. Hudson there are many interesting species, but one of the most striking points is the presence of two species of the family Blepharoceridae. The members of this family form a very isolated group, which occur in special localities in various parts of the globe. They apparently form a decadent family which has specialized in habit so as to maintain its existence, and the various members of it are usually found by mountain-streams which are highly aerated, in the waters of which the extraordinary larvae and pupae live. Accounts of the habits and morphology will be found in a paper “On the Net-veined Midges of North America,” by V. L. Kellogg, Proceedings, California Academy of Sciences, 3rd series, Zoology,
vol. 3, and in a monograph of the family by the same author published in Wytsman's “Genera Insectorum,” 1907.
The genera hitherto known are distributed as follows:—
Apistomyia. Corsica and Cyprus.
Paltostoma. St. Vincent, West Indies, Columbia, South America.
Kelloggina. Rio de Janeiro.
Blepharocera. Europe, East America, California.
Bibiocephala. America, Rocky Mountains and west.
Philorus. Europe and West United States.
In addition, I have seen a species from the Cape, which is to be described by Mr. F. W. Edwards; it appears to belong to the genus Kelloggina; and I have also seen an unnamed species from India.
The two new species here treated are of especial interest, as they carry the range of the family into the Australian region. The insects belong to two distinct genera. They have very minute hairy palpi, which are inserted at the base of the proboscis, and require careful looking for to see at all clearly. The proboscis is enclosed in a sheath which ends in two remarkable long processes, which in the males are as long as the parts forming the sheath. This character seems to be one which is not possessed by any of the hitherto-published species. The hind legs are excessively long, both absolutely and relative to the other pairs. The presence of long hind legs is very usual in the family, but none of the published figures or descriptions show the great disparity which exists in the present species.
The larger of the two species is represented by males only, and is shown three times the full size in fig. 1. The photograph is a little incomplete, as the specimen had lost the last joint of one hind tarsus and the last two joints of the other. It was selected for illustration as it was set out flat, so that the relative proportions can be easily measured. The figure shows very well the great length of the hind legs. In its general character it comes nearest to the genus Curupira (F-Müller) O. S. This genus was described and figured in great detail by F. Müller, “Archivos do Museo Nacional do Rio de Janeiro,” vol. 4, 1879, pl. 7. The differences between the present insect and the figures and description of Müller are so considerable that it is felt to be impossible to place it in that genus. Baron Osten Sacken (Berl. Ent. Zeit., vol. 40, 1895, p. 160) gave a warning against the multiplication of genera in such an evidently decadent family as the Blepharoceridae, pointing out that it may result in many genera becoming monotypical; but it is felt that having regard to the isolated position of the present species, and
the considerable differences existing, it is justifiable in this case to make a new genus.
Neocurupira gen. nov.
In Kellogg's monograph, “Genera Insectorum, Blepharoceridae,” 1907, a table of the genera known up to that date is given. The present species belongs to the section with no incomplete vein near the hind margin, and with holoptic eyes. This leads to the genus Curupira, as mentioned above. From that genus the present insect differs as follows: The long-ended tips to the tongue-sheath, the small palpi (Curupira has long palpi, vide Arch. Mus. Nac. R. Jan., pl. 7, fig. 20), and the very long hind legs.
The genus can be defined as follows:—
Eyes holoptic on the vertex, very hairy, divided into two regions, an “upper eye” and a “lower eye.” These two regions are absolutely contiguous, and have no intervening space; the upper eyes have large brown facets, the lower eyes have small black ones. The upper eyes touch from the well-marked ocellar “turret” to somewhat above the antennae; the lower eyes are widely and fairly evenly separated by the wide face. The turret bears 1 ocellus near the top and 2 on the sides towards the back. Palpi minute and hairy, almost hidden in a sort of depression each side of the base of the tongue. The tongue is longer than the vertical depth of the head, the sheaths are prolonged into 2 long flagella, which are jointed just at the tip of the tongue, where they divaricate (fig. 2). Antennae normal (fig. 3).
Thorax of normal form for the family. Wings as shown in fig. 4. The first vein is very close to the costa, and extends from about A to B in the figure. It is not shown in the drawing, which was made with a camera lucida, as it was almost in the same plane as the costa. There is a forked vein between the first and the fourth; no incomplete vein on hind margin; a cross-vein from the fourth to the one before, but none between the fourth and fifth.
The hind legs very long, both absolutely and compared with the others; femora elongate club-shaped; tibial spurs on the hind pair; claws simple, no visible empodia.
Abdomen, in the dried specimens, compressed laterally, with the usual large and complex hypopygium (fig. 5).
Type.—The following species.
Neocurupira hudsoni sp. nov.
Head as in figures. The vertex is small, so that only the black ocellar turret is visible. Upper eyes brown, lower black, both clothed with profuse dense brown pubescence. The lower margins of the lower eyes with long hairs. Antennae brown-black. Face grey; tongue, &c., black.
Thorax deep dull black, tiny orange humeral protuberances with orange patch behind; hind angles of thoracic dorsum and the pleurae above the wing-bases orange; lower pleurae dusted with grey. Scutellum margined with greyer black; metanotum more shining black. Wings as figured and described for the genus, glassy with black veins; the extreme base orange; a fine ciliation along the hind margin, which is longer at the extreme base and at the anal angle; the little chitinous patch at the angle of the axillary lobe is well marked; net veins evident, but showing no special characters.
Halteres with long pale stalks and flattened triangular brown heads.
Legs brownish-black, except for the front coxae, the base of the front femora, and the thin basal two-thirds of the hind femora, which are paler. Front femora bent and thickened towards the tip. Hind femora very long, about three times the length of the middle ones, spindle-shaped, with a slender basal part, which gradually thickens out into a slender club-shaped distal part. Two well-marked spines on the hind tibiae. All the claws simple, but thickened at the base.
Abdomen slender, compressed laterally in the dried specimens. Black, paler at the base, and indistinctly and narrowly so on the margins of the segments. Male hypopygium with the usual complex structure, and as shown in fig. 5 in side view: (a) is one of a pair of later terminal lobes, (b) one of a pair of dorsal lobes, (c) is a hood-like extension of the dorsal part of a segment, it is depressed in the centre but not bifid. The internal structures could not be studied, owing to the small amount of material, but as far as they can be seen are much like those figured in Kellogg's monograph, pl. 2, fig. 15.
Size.—About 8mm.; wing, about 8mm.
Locality.—Otira, New Zealand. The species is numbered 231 in Mr. G. V. Hudson's collection.
Type in Cambridge Museum.
Paratypes in the British Museum and at Cambridge.
The other species is represented by both sexes, and the male is shown three times full size in fig. 6. It is distinguished by the non-holoptic eyes (see fig. 7), which are just bisected by a furrow into lower and upper, while the facets are of nearly equal size. There is an unforked vein between the first and fourth, the general venation being very like that of Paltostoma (see Kellogg, “Genera Insectorum,” pl., fig. 21). The palpi are minute as in that genus, and the proboscis is long. The insect differs from Schiner's
generic description (Verh. der Zool. Bot. Gesellsh. in Wien, xvi, 1866, p. 931) in many important respects. The hind femora and metatarsi are long, as in Paltostoma, but the relative proportions of the tarsal joints are quite different; the metatarsus is the longest, and the second to last joints get progressively smaller and smaller. There are no spines on the last joint. Neither in Schiner's description nor in Williston's figure of P. schineri (Trans. Ent. Soc. London, 1896, pl. 8, fig. 27b) is there any mention or sign of the extraordinary ocellar turret which will be seen from fig. 7 to be so large in the present species. Furthermore, there is no mention in Paltostoma of a cross-line dividing the eyes into-lower and upper halves, nor is any such line shown in Williston's figure.
Peritheates gen. nov.
♂ Head.—Eyes separated by a broad space from the vertex to the mouth, this space being nearly equally wide for the whole distance. The eyes are bisected by a somewhat shallow groove into smaller upper and larger lower halves; the whole eye very pubescent, and the upper eye-facets but little larger than the lower. The vertex has a very prominent and elegant ocellar turret; the front ocellus is on the front side of the turret, and the others one on each side. The tongue is long, with a sheath furnished with two long processes like the last species. The palpi are minute and almost hidden at the base of the tongue. In vertical view the face is seen to project in the form of a broad keel standing out beyond the plane of the eyes and the normal-shaped antennae are inserted towards the sides of this keel.
Thorax.—Very like that of the last genus. Wings as in fig. 8. An unforked vein between first and fourth and a cross-vein between this middlevein and the fourth. Net-veining well marked; but normal.
Legs long, especially the last pair; femora spindle-shaped; hind tibiae with 2 spines; claws normal; no visible pads.
Abdomen.—Slender and laterally compressed as the last genus, with the usual complex hypopygium.
♀. The long processes to the tongue-sheath are much shorter. The legs are shorter in proportion, especially the hind legs. The abdomen is cylindrically pointed.
Note.—In one of the ♀ specimens the last vein in the wing does not meet the margin.
Type.—The following species.
Peritheates turrifer sp. nov.
Head.—Vertex, turret, and all the eyes black, the latter with a profuse light-brown pubescence. Face greyish; tongue brown, with brown-black sheath. Antennae black.
Thorax.—Dorsum deep dull black slightly pollinated with grey; humeral knobs orange on the tip; hind angles of dorsum just above the wing-bases lined with orange; pleurae profusely pollinated with grey. Scutellum in outline like a very blunt-pointed long-based triangle. Wings as in the generic description, glassy with black veins, orange at the base; the chitinous patch at the anal angle well marked; hind margin finely ciliated, especially from the extreme base round the anal angle.
Halteres with long pale stalk and long oval head of darker colour.
Legs black, except for the front trochanters, base of front femora, middle trochanters and base of femora, hind trochanters, and basal four-fifths of femora, which are paler. Front femora slightly bent and swollen from middle to tip; middle femora straight, but similarly swollen; hind femora about three times as long as the middle ones, very thin for the basal two-thirds, then swelling out into a slender spindle shape. Hind tibiae with two spurs. Front and hind metatarsi very long, about as long as the rest of the joints; middle shorter, about as long as 2 ½ joints.
Abdomen.—Slender, compressed laterally, brown-black with well-marked orange margins to the segments. Male hypopygium in side view as fig. 9, with end and upper pair of processes.
The ♀ specimens were immature. All the legs are slender and proportionately shorter than in the ♂.
Size.—4 ½ mm.; wing, 6 mm.
Locality.—Otira, New Zealand. This species is numbered 230 in Mr. G. V. Hudson's collection.
Types in the Cambridge collection.
Paratypes in the British Museum.
Note by G. V. Hudson, F.E.S.
Both insects described by Mr. Lamb in the foregoing paper were captured flying over the foaming waters of Warnock's Creek, Otira River, on the 5th and the 13th December, 1908. They frequented only the most disturbed portions of this violent mountain-torrent, where the noise of the falling waters was deafening. Both species seemed to be engaged in nuptial dances amongst the flying spray, the long hind legs of the males being held out behind, looking like the caudal appendages of an Ephemera. I secured both sexes of Peritheates turrifer, but could find only males of Neocurupira hudsoni; they rested on the wet boulders close to the water's edge. These insects seem to be very local, as I have not observed either of them on any other occasion. Dr. Chilton described a larva of a Blepharocerid in vol. 38, p. 277, of the “Transactions of the New Zealand Institute.” I observed similar larvae in the streams at Otira during my visit. They are very probably referable to the insects described in the foregoing paper.