Descriptions of the Immature Stages of some New Zealand Crane-flies: Part 1.

Transactions and Proceedings of the Royal Society of New Zealand, Volume 58, 1928, Page 301

Descriptions of the Immature Stages of some New Zealand Crane-flies: Part 1. By J. Speed Rogers, University of Florida, Gainesville, Fla., U. S. A. (Communicated by A. L. Tonnoir, Cawthron Institute, Nelson.) [Read before the Nelson Philosophical Society, 28th September, 1927; received by Editor, 29th September, 1927; issued separately, 8th November, 1927.] Through the kindness of my friend, Dr. C. P. Alexander, of Amherst, Mass., I have received an important collection of immature stages of New Zealand crane-flies. These larvae and pupae were sent to Dr. Alexander by Messrs. Tapely, Gourley, Harris, Highway, Campbell, and Lindsay of New Zealand, who, in the majority of cases had reared a part of the specimens and so made identification of the larvae and pupae possible. The identifications of these reared imagos are due to Dr. Alexander. I wish to express my gratitude to Dr. Alexander and the several New Zealand entomologists named above, for the opportunity to study this well-preserved and valuable mate-rial, which includes larvae and pupae of several genera whose imma-ture stages were unknown. The present instalment of these descriptions is concerned with the identified immatures of the genus Macromastix Osten Sacken, one of the genera whose larval and pupal stages remain undescribed. Macromastix albistigma Edwards. The Egg. Length, 0.75 mm.; diameter at midlength, 0.45 mm. Form short, rounded elliptical. Chorion rigid, tough, unsculptured; in alcoholic specimens, dull brownish black, the smooth surface rather opaque. The Larva. Length, 16.5–20 mm.; diameters of the 2nd abdominal segment: dextro-sinistral, 6–6.5 mm.; dorso-ventral, 5 mm. Form robust, mod-erately flattened dorso-ventrally, oval in cross section. Body thickest in region of first three abdominal segments; thoracic and posterior abdominal segments of about equal depth and breadth; anterior and posterior extremities blunt. Colour (alcoholic specimens), a dull cinnamon-buff, somewhat darker on dorsum of thorax. Integument opaque, leathery, tough; bearing an even, moderately dense, growth of minute hairs nearly concolourous with integument. Setae small, weak, inconspicuous; when broken the setigerous punctures hardly evident. The abdominal somites are divided into anterior and posterior annuli, the former with several transverse wrinkles across dorsum, the latter somewhat the longer and more smooth. Abdominal segments 7 and 8 with a caudo-

laterally directed, fleshy tubercle at each caudo-lateral margin. (Those of segment 8 shown in fig. 6). Segments 5 and 6 have very minute tubercles in the same positions. Spiracular disk dorso-caudal. When expanded (fig. 7) occupy dorsal half of caudal aspect; when contracted (fig. 6) visible only as a transverse dorsal slit at about two-thirds the length of 9th abdominal segment. Of the six lobes borne by disk, the ventral pair are very large and fleshy, almost fused in median line; their apical margins with brown, chitinized lines. When disk is expanded the faces of ventral lobes are at right angles to vertical face of disk proper and form a horizontal shelf whose area is equal to that of disk. In contracted condition the faces of ventral lobes are turned upward to a nearly vertical position, concealing spiracles and face of disk, and in this position the fleshy caudo-ventral faces of ventral lobes form a tumid caudal end to the larva. From the middle of the caudo-ventral face of each lobe is borne a small, cylindrical, fleshy papillus. The disk proper is sub-quadrangular, the long dimension of quadrangle, dex-tro-sinistral. The nearly circular spiracles are dark brown, their centres a dead black; they are separated by about once and a half times diameter of one spiracle. The slender, conical, dorso-lateral lobes project dorsad from dorso-lateral angles of disk and at about mid-length turn abruptly laterad; the caudal face of their bases has a chitinized, faint brown line. The paired dorso-median lobes are very small, rounded, chitinized projections to either side of dorso-median line. From cephalic surface of each arises a small, fleshy, conical papillus that projects dorsad well beyond lobe itself. Save for the spiracles and chitinized areas noted, disk is concolourous with rest of abdomen. The anal gills have the form of a broad circum-anal ring that is radially wrinkled, and are opaque white save for a dark brown, chitinized outer portion. When gills are retracted only this chitinized outer portion is visible. Apparently the gills serve as an organ of locomotion. Head capsule (fig. 1), broad, massive, compact, heavily chitinized. Length, 3.5 mm.; breadth, 2 mm.; greatest depth (mid-length of lateral plates), 1.3 mm. Prefrons a long narrow triangle, its slightly concave base forming anterior margin, posterior apex slender, elongate; anterior two-thirds heavily chitinized, dark brown. Lateral plates mussel-valve-like in shape; anterior three-quarters and entire margin heavily chitinized, dark brown; the centre of posterior quarters membranous, yellowish brown, ventro-mesal anterior margins projecting to form the bars of mentum, toward lateral angles of dorsal cephalic margins with a single stout, long seta. Clypeus shallow crescentic, chitinized, dark brown; cephalo-lateral horns with a single, erect, brownish yellow seta. Labrum epi-pharynx rectangular, almost square; a transverse groove caudad of its cephalic margin; back of this groove the surface is slightly depressed, saucer-like, conspicuous whitish yellow; anterior to groove with cephalo-lateral margins chitinized, dark brown, bearing numerous long, stiff hairs and a pale slender papillus-like rod, the median cephalic portion emarginate. Antennae with first joint stout, cylindrical, dark brown except for yellow apex; 2nd joint minute, elongate oval, yellowish white. Man-

1. Head capsule of larva, Macromastrix albistigma Edw. 2. Mandible of larva, M. albistigma Edw. 3. Hypopharynx of larva, M. albistigma Edw. 4. Mentum of larva, M. albistigma Edw. 5. Maxilla of larva, M. albistigma Edw. 6. Ninth abdominal segment and contracted spiracular disk of larva, from above, M. albistigma Edw. 7. Expanded spiracular disk of larva, caudal aspect, M. albistigma Edw. 8. Pronotal breathing horn of pupa, M. albistigma Edw. 9. Pupa of M. albistigma Edw., ventral view.

dibles (fig. 2) stout, heavily chitinized; three blunt, cylindrical, apical, teeth, median tooth the largest and curved slightly mesad; a minute elevation at the base of dorsal tooth; dorsal margin near base of mandible, rounded, protruding, the crest of this protuberance minutely crenate; remainder of mandible smooth, the edges rounded; a pair of long setae borne from a common pit on proximo-lateral angle of ventral face. Prosthecal appendage a long, hairy papillus with a tuft of longer, yellow hairs at its apex. Maxillae (fig. 5) smaller than mandibles, flattened, sclerites distinct. Cardo large, sub-quadrangular, a pair of long, erect hairs borne from a common depression near middle of its anterior ventral face. Stipes a short, thick cylinder, slightly dilated distally, its proximal margin very oblique; apically it bears a prominent, conical palpal joint and, just before apex, a long stout seta that curves toward tip of palpus. Outer lobe short and stout with a pair of setae from a common pit at base of ventral surface; the rounded apex with a dense growth of yellow hairs and, on inner surface, a small chitinized cone. Inner lobe smaller, flattened triangular, and bears a small tuft of hairs directed meso-cephalad. Mentum (fig. 4) broad, prominent, barely constricted back of bases of lateral teeth; median tooth long, projecting; to either side three lateral teeth, smaller and flatter than median tooth; caudal cleft extends cephalad to a point opposite bases of second lateral teeth. Hypopharyngeal plate (fig. 3) narrow, anteriorly with a triangular median tooth and a pair of broad, incompletely double lateral teeth. The Pupa (Figs. 8, 9 and 11). Length, 17–19.5 mm.; diameters at base of wing-pad: dextro-sinistral, 3.5 mm.; dorso-ventral, 3.7–4 mm.; width of 5th abdominal segment, 5–5.5 mm. Form cylindrical in the thoracic region, the head irregularly conical, the abdomen flattened dorso-ventrally, markedly so in the pleural region. Colour (alcoholic specimens): the older pupae dark brown save for the pronotal breathing-horns, the stigma region of the wing-pads and the central portions of the basal abdominal segments which are yellow or orange yellow; in the younger pupae the yellow is much more extensive, the brown restricted to margins of sclerites, eyes, and face. Head terminating anteriorly in a large, blunt, irregularly conical tubercle, ventro-cephalic face of this tubercle sculptured with transverse chitinous ridges. The antennae arise immediately ventrad to base of cephalic tubercle, the space separating their bases narrow; they curve first dorsad along bases of tubercle, then caudad around eyes to terminate at a little less than a fourth the length of the wing-pad. Each antennal base is ornamented with several prominent, acute, conical points; of these the middle pair is the largest, wholly chitinized, dark brown, their apices slightly divergent; the members of the next pair are small, slightly caudo-lateral to the first; the third pair is intermediate in size, their bases laterally compressed. Cheeks flattened, their caudo-lateral margins projecting as acute lobes. Front moder-

ately broad. Labrum large, its surface broadly convex, with a small rounded elevation bearing two chitinized points near its mid-proximal point; bluntly constricted before apex which ends in an obtuse point. Labial lobes barely contiguous medially, roughly subquadrate. Maxillary palpi elongate, narrowing to acute tips; they extend along ventral margin of cheeks to antennal sheaths where they bend caudad and extend for a short distance contiguous and parallel to antennal sheaths. 10. Pupa of M. dichroithorax Alex., ventral view of anterior end. 11. Diagram of spine arrangement of fifth abdominal segment of pupa of M. albistigma Edw. 12. Diagram of spine arrangement of fifth abdominal segment of pupa of M. dichroithorax Alex. 13. Diagram of spine arrangement of fifth abdominal segment of pupa of M. huttoni Edw. 14. Diagram of spine arrangement of fifth abdominal segment of pupa of M. atridorsum Alex. Prothorax rather long, its apical margin with a broad, median V-shaped emargination. Pronotal breathing-horns (fig. 8) elongate (length, 2–2.5 mm.), cylindrical, their bases widely separated; save at apices, the surface distinctly corrugated; apices rounded, smooth, divided into hemispheres by a shallow, terminal incision. Between the level of the pronotal breathing-horns and the cephalic margin, the pronotum bears two pairs of widely separated minute tubercles, their margins chitinized and minutely crenate.

Mesonotum slightly gibbous, smooth, without ornamentation. In some pupae the V-suture of the adult is slightly indicated. Wing-pads extending to the anterior end of the third abdominal segment. In older pupae a large, white stigmal area is conspicuous. The tarsal sheaths end at markedly different levels: prothoracic tarsi end opposite the posterior annulus of the 5th abdominal segment; mesothoracic tarsi end opposite the same region of the 6th segment; the slightly longer metathoracic tarsi end at anterior end of 7th segment. In specimens with curved abdomens the position of the tarsi relative to the abdominal segments may be shifted. Abdominal segments 2 to 7 are divided into distinct basal and distal annuli. Ventrally the basal annuli are unarmed, the distal annuli bearing four acute, curved, chitinized points, a pair to either side of the tarsal sheaths. Dorsally the basal annuli are unarmed, the distal annuli with a transverse row of chitinized points at distal margins. These points range in number from 16 (segments 2 and 3) to 8 (segments 6 and 7). In pleural region basal annuli have a single, long, curved, chitinized point; distal annuli a group of three similar points. Segment 8 bears a circle of 6 large conical tubercles chitinized toward apiees. Cauda of female with sternal valves short, straight, hardly projecting beyond the rest of segment; tergal valves well dorsad of ventral, small, rounded, separated medially. Above dorsal lobes is a group of three conical tubercles. Described from larvae taken from rotten log of Eucalyptus globolus, Governor's Bay, New Zealand, Nov. 28, 1922, and from pupae reared from this lot of larvae by Mr. J.F. Tapley. Other lots of material of this species were from Governor's Bay and from Ric-carton Bush, Christchurch. Macromastix dichroithorax Alexander. The Pupa (Figs. 10 and 12). Length, 15–16 mm.; diameters at base of wing-pads: dextro-smistral, 2.5 mm.; dorso-ventral, 2.5 mm.; breadth of 5th abdominal segment, 3 mm. Form cylindrical, rather slender. Colour (alcoholic specimens), an almost uniform chestnut-brown save for transverse bands of brownish yellow on the abdominal ser-gites and sternites, and the pleural region of the abdomen light brown. Head with a prominent, bluntly conical cephalic tubercle; surface of this tubercle roughened with transverse chitinous ridges and bearing on latero-dorsal faces two pairs of very small secondary tubercles. Antennae arising from slightly dilated bases at ventro-laterad margins of cephalic tubercle and ending a short distance beyond bases of wing-pads. Cheeks with their ventro-laterad angles projecting. Labrum markedly convex, proximal margin abruptly elevated, with transverse wrinkles whose crests are chitinized. Labial sheaths elongate, mesal ends rounded, barely contiguous. Maxillary palpi tapering evenly to slender apices gently arcuated where they cross the knees of prothoracic legs, to end in contact with antennal sheaths.

Prothorax rather elongate dorsally. Cephalic margin with a deep U-shaped median notch and rounded lateral angles whose surfaces are slightly tumid. Pronotal breathing-horns yellowish, 0.9 mm. long, slender, cylindrical, somewhat constricted at bases; surfaces corrugated almost to tips which are faintly bisected. Mesonotum with fine furrow-like, transverse ridges that are most marked on dorso-lateral angles of prescutellar region. Wing-pads reaching to caudal margin of 2nd abdominal segment. Tarsal sheaths ending opposite 5th abdominal segment: prothoracic at cephalic margin, mesothoracic opposite basal annulus, metathoracic opposite caudal margin of distal annulus. Metanotum narrowly ridged along cephalic margin. Abdominal segments 2 to 7 divided into distinct basal and distal annuli, sub-equal in length. On dorsum the basal annuli are unarmed; distal annuli bearing at mid-length or slightly beyond, mid—length, a row of small, chitinized points that curve caudad. On segments 2 and 3 the points are 14 in number; on segment 4, 11; on segments 5 and 6, 10; on segment 7, 8. In pleural regions each basal annulus and distal annulus of segment 2, bears a single, large, chitinized point, curved caudad at mid-length, distal annuli of segments 3 to 7 bear two such points. The sternites have basal annuli and distal annuli 2 to 5 unarmed; distal annulus of segment 6 has a single curved point at either side of median line, and that of segment 7, a row of 4 such points, two on either side of median line. The lobes of segment 8 acute, tips chitinized, bases dilated. Cauda with lobes tipped with acuminate chitinous spines. Described from a lot of 14 pupae labelled, “Canterbury, New Zealand.” Macromastix huttoni Edwards. Pupa Skin (Fig. 13). Length, 14.6 mm.; diameters at base of wing-pads: dextro-sinis-tral, 2.9 mm.; dorso-ventral, 2.5 mm.; breadth of 5th abdominal segment, 3 mm. Form approximately terete. The “skin” with a yellowish-brown tinge, deepening to brown on coxae, labrum, mouth parts, and margins of sclerites. Cephalic tubercle evident, although split longitudinally by the emergence of imago, its surface lined with minute transverse wrinkles; a pair of small, relatively smooth secondary tubercles on dorsal surface. Antennal bases angulate; tips of antennae, if in normal position, would extend to slightly below bases of wing-pads. Sheath of labrum somewhat tumid, the transverse lines of its surface faint. Cheeks with the caudo-lateral angles projecting. Labial lobes scarcely contiguous medially. Maxillary palpi conical, tapering to slender apices that curve caudo-lateral to about reach antennal sheaths. Pronotal breathing-horns yellowish, 1.3 mm. long; flattened cylindrical, oval in cross-section; surfaces corrugated; tips shallowly cleft in their long diameter. Wing-pads ending slightly before caudal margin of 2nd abdominal segment. Tips of tarsal sheaths oppo-

site 4th abdominal segment: prothoracic opposite basal annulus, the nearly level meso–and metathoracic tarsi opposite distal annulus. Abdominal segments 2 to 7 divided into distinct basal and distal annuli, the latter slightly less than twice length of the former. On dorsum, basal annuli unarmed; distal annuli with a row of from about 12 (segment 2) to 8 (segment 7) small, caudally curved, chitinized points at a little beyond mid-length. In pleural regions basal annuli have a single, slender, long, curved, chitinized point, very small on segment 2; distal annuli bear two such points. The sternites have basal annuli unarmed; distal annuli also unarmed save for a single small point in median line of segment 4, a similar but larger point on segment 5, a row of 7 points on segment 6, and a row of 6 larger points on segment 7. Segment 8 with the six lobes acutely pointed, their-bases somewhat thickened. Lobes of cauda small, blunt, save for a pair of large, pointed dorso-median lobes and a smaller pointed lobe just laterad of each dorso-median lobe. Described from a single pupa skin (female) labelled, “Hatched out Feb. 2, 1924 Qhakune, Wellington.” (T. R. Harris). Macromastix atridorsum Alexander. Pupa Skin (Fig. 14). Length, 11.2 mm.; diameters at base of wing-pad: dextro-sinis-tral 2 mm.; dorso-ventral, 2 mm.; breadth of 5th abdominal segment, 1.7 mm. Form slightly conical, thickest at base of wing-pads, from there tapering slightly to caudal end. Colour of pupa skin dark brown. Cephalic tubercle scarcely evident (this may be due to its being entirely split), smooth, without secondary tubercles. Antennae very short, not reaching the bases of the wing-pads. Caudo-lateral angles of the cheeks acutely projecting. Labrum very faintly sculptured, apparently little or not at all tumid. Maxillary sheaths similar to those of M. huttoni but shorter and more slender, scarcely reaching antennal sheaths. Prothoracic breathing-horns brownish, 0.6 mm. long, surfaces corrugated. Wings extending to cephalic margin of 3rd abdominal segment. Tips of tarsi opposite distal annulus of segment 5; the prothoracic at cephalic margin of annulus, the almost even meso- and metathoracic tarsal tips at caudal end of annulus. Abdominal segments 2 to 7 with distinct basal and distal annuli, the latter somewhat the longer. Dorsum with basal annuli unarmed; distal annuli with a transverse caudal row of from 14 (segment 2) to 8 (segment 7), minute, chitinized points. The pleural regions with basal annuli bearing a single, chitinized point; distal annuli with a group of one larger and two smaller points. The sternites with basal and distal annuli unarmed save that distal annulus of segment 7 bears a pair of widely-separated, curved points at about mid-length. The lobes of segment 8 acutely pointed, arcuated through 90 degrees. Cauda with lobes slender, tips acuminate, curved, chitinized.

Described from the pupa skins of two males. The pupae were taken from leaf mould by Mr. T. R. Harris, at Ohakune, Wellington. The imagos emerged October 20, 1924. In addition to the larva and pupae described above, the collection contains several vials of unidentified larvae, that belong, without doubt, to the genus Macromastix. Some of these are almost certainly M. albistigma Edw., the others belong to two unknown species. The larvae of three species and the pupae of four are, no doubt, insufficient to permit an attempt to characterize the immature stages of so extensive a genus as Macromastix or a comparison with the immature stages of Tipula, which are still most imperfectly known. Certainly the immature stages of Macromastix seem as close to those of Tipula as would be expected from a consideration of the imagos. The most striking, though not necessarily absolute, differences, judged from the present material, appear to be: The larvae of Macromastix with anal gills un-lobed, ring-like; the disproportionately large ventral lobes of the spiracular disk, with their tumid, fleshy caudo-ventral margins; the slight development of setae on the body segments; the much stouter, blunter body form, with a more marked tendency to subdivision of the body into annuli; and, possibly, the form of the hypopharynx. In these characters the two unknown larvae resemble M. albistigma Edw., as they do in the general structure of the head capsule, but they show a much more Tipula like form of antennae and mandibles than does M. albistigma. The known pupae of Macromastix appear to agree in showing the following differences from Tipula: The pronotal breathing-horns equal; a transversely sculptured cephalic tubercle; the surface of the labrum tending to be tumid and sculptured with transverse lines (slight in M. atridorsum); the maxillary palpi not recurved; lobes of the eighth abdominal segment six, tending to be grouped in threes toward the lateral sides of the segment; and the relatively small caudal lobes. Judging from the specimens at hand, the separation of the larvae or pupae of the species of Macromastix will not be more difficult than the separation of imagos. The three larvae before me show distinct and absolute differences in body form, spiracular disk and especially in the form of the labrum, mentum, mandibles, antennae, and maxillac. In the pupae the ornamentation of the abdominal segments will easily separate the four species described, which also show distinct differences in size, shape, length of pronotal breathing-horns, antennae, wing-pads and tarsal sheaths, and in the shape of the labrum and cephalic tubercle.