Yarrhpelopia norrisi, Cranston, Peter S., 2017

Cranston, Peter S., 2017, A new genus and species of Australian Tanypodinae (Diptera: Chironomidae) tolerant to mine waste, Zootaxa 4263 (2), pp. 369-377 : 371-376

Yarrhpelopia norrisi sp. nov.

rn:lsid:zoobank.org:act: 343A5777-5C64-4B8C-837C-469AC60D4AE2

Type material. Holotype Le / Pe / ♂, slide mounted in Euparal , ANIC, AUSTRALIA: New South Wales ( NSW), Captains Flat , Molonglo R., 35°35.29”S 149°26.46’E, 21.ix.2016, P.S. Cranston, MV NSWCF-10 . Paratypes (proposed molecular vouchers (MV) all ANIC): as Holotype, Le / Pe / ♂, MV NSWCF-8; Le / Pe / ♀, MV NSWCF-6; Pe / ♂, MV NSWCF-5; Pe / ♀, MV NSWCF-4; 3L MV NSWCF-1-3; non-MV, as Holotype except 2L, Pe ; as Holotype, 11L, 'C1Q1', 12.v.1988, B. Atkins, 5L, 'C1Q2', 28.v.1988, B. Atkins; Le / Pe / ♀, as Holotype except 12.ii,1988; Le / Pe ,/ ♂, NSW, Foxlow , nr. Captains Flat , 35°30'S 149°20'E, 12.ii.1988, Cranston.

Other material [all AUSTRALIA, in ANIC] : NSW: 2 Pe, P ♂, Warrumbungles, Timor Rock, Shawn's Ck., 31°16'S 149°09'E, 15.ix.1989, Cranston; P/ ♀, Bugong Rd, Kangaroo V., xi.1990, Edward; Pe, 6 km n.e. Nerriga, Endrick R., 35°05'S 150°08'E, 1.ix.1998, Cranston; Pe, Morton N.P., Corang R., 35°15'S 150°06'E, 25.v.1994, Cranston; Pe, Molonglo R., above Captains Flat, 35°35'S 149°28'E, 6.iii.1993, Cranston; Le / Pe /m, Le / Pe /f, Pe, Brown Mt, Rutherford Ck., 36°36'S 149°47'E, 16.x.1990, Cranston & Edward; 3 Pe, Kosciuszko N.P., Spencers Ck., 1730m asl, 36°26'S 148°22'E, 2.i.1988, Cranston; Pe, Tantawangalo S.F., Wog R., 37°05'S 149°35'E, 13.iii.1993, Cranston. ACT (Australian Capital Territory): Pe, Brindabella Ranges, L. Blundells Ck., 35°22'S 148°50'E, 21.xii.1977, Willis; Le /P, Lees Ck., 35°22'S 148°50'E, 24–25.ii.1998; 3 Pe, Mt Gingera, 35°34'S 148°48'E, 18.xii.1992, Cranston . Victoria, Pe, Tambo R., Currawong Ck., 36°58'S 147°54'E, 11.xi.1990, Hortle; 3Pe,, East Gippsland, Bonang Hwy/ Gap Rd. , 37°14.5'S 148°45.5'E, . ii.1992, Cranston. Tasmania, 2 Pe, Peters Link Rd., 41°09'S 148°07'E, 24.ii.1993, Cranston; Le/Pm, nr St Helens, Rattrays Marsh, 41°12'S 148°09'E, 24.ii.1993, Cranston; 4Pe, King Solomon's Jewels, pond #2, 41°47.8'S 146°16.5'E, 17.iii.1997, 1185 m asl., Wright; Pe, Cradle Mt. - L. St Clair, N.P., Frog Flat, 41°50'S 146°00'E, 25.i.1990, Cranston; Pe, Strahan S.F., Lake Ashwood , 26.iii.1997, 42°06'S 145°17.5'E, Wright; 3Pe, Central Plateau , small lake nr. L. Ada, 42°52'S 146°28'E, 15.iii.1997, 1160 m. asl., Wright . South Australia, Pe, Ewens Ponds , 38°01'S 140°49.5'E, 19.xii.1996, Wright.

Description. Adult male (n=6) total length 2.2–3.6 mm, wing length 2.0– 2.6 mm. Yellow-brown, scutal vittae mid-brown, scutellum darker brown-black. Wings unmarked. Legs light brown. Abdomen basically pale yellow with ovate to dumbbell-shaped, darker brown area anteriorly on each segment, area slightly larger posteriorly until pale segment VIII. Genitalia pale brown.

Head. AR c. 1.7, terminal flagellomere tapering, 4.5× as long as broad, terminating in strong seta ( Fig. 1 A); penultimate flagellomere 7× terminal flagellomere. Eye with 7–8 ommatidia long dorsomedial extension. Temporal setae 10–12 closely aligned medially, sparser dorsally. Clypeal setae 14. Palp well developed, total length 750, each segment longer than preceding, seemingly lacking sensilla clavata (neither single or aggregated). Scape bare, pedicel with 2 lateral setae.

Thorax. Scutal tubercle absent. Antepronotal setae 1–2, fine; acrostichals 28, uni-biserial between the vittae ending in anterior prescutellar field; dorsocentrals 28, arising anteriorly in humeral field, multiserial in humeral area, uniserial between vittae, expanded posteriorly; supraalars 0; prealars 10–11; scutellars 16. Preepisternum bare.

Wing ( Fig. 1 B). Costa extending to apex of R4+5, ending subapically, proximal to end of M1+2; R2+3 weak, running midway between approximated R1 and R4+5; R2 faint, terminating in costa near apex of R1. MCu above FCu, VR c. 1.0. Membrane unpatterned, densely setose in all cells and all veins. Anal lobe rounded. Squamal setae 24– 28.

Legs. LR1 0.89–0.91, LR2 0.68–0.70, LR3 0.72–0.78; all legs densely setose, with beard ratio on all legs maximally 4, lacking any tarsal brush on tarsomere 3 of mid legs. Tibial spurs ( Fig. 1 C), lengths: P1 35; P 2 30, 50; P 3 30, 53; tibial comb of P3 with 3 subequal setae. Claws very slender, slightly curved, distally pointed, simple. Pulvilli absent.

Hypopygium ( Fig. 1 D). Tergite IX posteriorly with irregularly aligned 6 setae; "anal point" obscure, broad and rounded, microtrichiose. Gonocoxite 190 long, 2× as long as broad, cylindrical, microtrichiose mediobasally, with evidence of mediobasal swelling, interpretable as volsella in some orientations, weak otherwise, a weakly developed anal point extending from tergite IX which bears 5–8 setae along its posterior submargin ( Fig. 1 D). Gonostylus 120 long, well developed, swollen at base, tapering in apical 2/3, terminal spur 15 long. Phallapodeme long, sternapodeme inverted V-shape ( Fig. 1 D).

Adult female (n=3), as male in colour and non-dimorphic features. Total length 1.8 mm, wing length 1.9 mm. AR 0.24, terminal flagellomere 115 long, tapering, apex with strong seta. Dorsomedial extension of eye 4–5 ommatidia wide. Temporal setae 10–12, linear uniserial. Clypeal setae 29. Palp as male. Scape bare, pedicel with 7 setae forming semicircle. Many thoracic setae bimodal in length (and size of pit): antepronotal seta 1; acrostichals 30; dorsocentrals 29; supraalars 0; prealars 14; scutellars 26. Squama 18. LR1 0.79, LR2 0.73, LR3 0.74–0.78; Tibial spur lengths: P1 38, P2 35, 50, P3 35, 50.

Genitalia. Gonocoxapodeme VIII mid-brown, gently curved, tapering medially. Gonapophysis VIII triangular. Gonotergite IX without setae. Notum well developed, twice length of seminal capsule, free part of rami pale. Tergite IX thin, non-setose. Postgenital plate large bearing small pediform cerci. Three ovoid to globular seminal capsules, 75 long, spermathecal ducts bare, straight, ending separately

Pupa (n=10). Length 5.2 mm. Cephalothorax grey including wing sheaths; abdomen TI grey, remainder pale to mid-yellow, each with antero-median grey patch; apophyses golden.

Cephalothorax. Thoracic horn ( Fig. 2 A) cylindrical, flattened in antero-ventral plane, slightly curved, near parallel-side in lateral view, terminally rounded; 275 long, 5× maximum width, external membrane with spines nearly united into irregular mesh. Horn sac tubular, occupying full lumen, with short angled connection to plastron at about 90% length from base. Corona wide, occupying about 20% length of thoracic horn, plastron plate ovoid, angled to long axis. Basal lobe tubercular c 35 long. Thoracic comb comprising 12–20 short tubercles, longest 10 long and dorsad, biserial medially. Thorax weakly spinulose; without scutal or postnotal tubercle. Single antepronotal seta retracted from margin, other thoracic setae difficult to discern: only 1 weak precorneal seta; dorsal setae 1 and 2 present, simple, 2 displaced laterally close to anterior wing sheath base, dcs4 taeniate, in supraalar position.

Abdomen ( Fig. 2 B). Tergite I with scar, lateral muscle marks very weak. Abdominal spinulation (shagreen) (Fig, 2C) fine, aggregated form short rows, spinules larger and denser and in triplets medially or aligned laterally especially on more posterior segments. L setae taeniate only on segments VII (4, clustered in posterior half) and segment VIII (all 5, evenly spaced). D setae: 3 on I, 4 on II, 5 on III–VII, absent on VIII; O-setae: 1 pair dorsal, 1 ventral, situated mid-curve of apophyses. Anal lobe ( Fig. 2 D) about 1.5× as long as broad, microspinulose, outer borders with spinules, inner border convex, outer border curved. Anal macrosetae adhesive. Gonopodial sheath of female short, spinulose; of male smooth, extending c. 70% length of anal lobe,

Larva (n=10). Body length 5.4–5.8 mm, head capsule length 550–580, golden-yellow with narrow cephalic margin slightly darker golden-brown; mandible golden, tip brown, ligula golden brown grading to dark brown distal half, anterior parapod claws fine and pale, posterior claws broader, simple, golden-yellow. Capsule longishoval, cephalic index 0.7–0.75. Cephalic setation ( Fig. 3 A): S10, VP and S9 aligned at 45° to longitudinal axis, SSm retracted, posterior to S10 and more median than S9, dorsal pit present, S7 close to S8, S5 only slightly proximal to DP.

Antenna ( Figs. 3 B, C) slightly longer than head length, segment lengths: 255–300: 74–84: 6: 5–6, AR: 3.0; basal segment c12× as long as basal width, ring organ distal to mid-point (60%); Blade bifid, broad outer branch 82–90, slightly longer than thin inner branch. Lauterborn organs (peg sensilla, Saether 1980) very short, 2–3, style c. 15 extending to near apex of antenna ( Fig. 3 C).

Mandible ( Fig. 3 D) gently curved, with bluntly tapering apical tooth, 95 long; short, rounded inner tooth not projecting, long seta subdentalis arises from projecting tooth-like distal mola. Ventrolateral setae close on outer margin, separated from sensillum minusculum by less than distance from posterior most seta 3.

Ligula ( Fig. 3 E) with 5 teeth, row concave, with outer teeth directed anteriorly, point of inner teeth curved outward; ligula weakly constricted medially; narrow rectangular area of muscle attachment occupying basal 8– 10%. Paraligula bifid, with outer branch near half length of ligula, inner much shorter. Pecten hypopharyngis with 12–13 teeth, quite homogenous in size or diminishing slightly laterad.

Maxillary palp ( Fig. 3 F) with basal segment 40 long; faint ring organ situated subapically at 75% length; crown with well-developed setae and sensilla including 2-segmented b-sensillum with basal section about 3x length of apical section.

Submentum ( Fig 3 G) anteriorly with transverse 'creases' of lighter sclerotisation, extending laterally and posteriorly to near occipital margin, less far ventrally Dorsomentum with 3 small lateral teeth; M appendage uncertain, vesicles not distinguishable. Pseudoradula 14–15 wide, essentially parallel-sided, densely granulose without clear alignment, posteriorly without contact to ventral hypopharyngeal apodemes.

Abdomen. Body without a fringe of swim setae. Anterior parapod claws simple, pale. Anal tubules slender, shorter than half length of posterior parapod, tapering apically, about 4× as long as basally wide. Procercus evenly darkened about 3× as long as wide (100 × 35), with 7 anal setae of length 500. Subbasal seta of posterior parapod simple. Posterior parapods simple, yellow with 12–14 short and triangular to long and narrow claws; with at least 1 small and 1 medium-length claw having an hyaline outer crescent ( Fig. 3 H). Claws subtended on parapod by subapical area of few fine spinules.

Etymology. The specific epithet norrisi recognises the late Professor Richard Norris, eminent freshwater biologist, whose interests in the pollution of the Molonglo River by the Captain’s Flat mine extended over several decades. To be treated as a noun in apposition.

Figures

FIGURE 1. Yarrhpelopia norrisi gen. n. sp. n. Adult male. A. Antennal apex; B. Wing; C. Tibial apices, TI – TIII L to R; D. Hypopygium, left side dorsal, right side stylised ventral / internal.

FIGURE 2. Yarrhpelopia norrisi gen. n. sp. n. Pupa. A. Thoracic horn and thoracic comb; B. Dorsal abdomen; C. Tergite IV spinulation (' shagreen'), detail; D. Anal lobe, left half.

FIGURE 3. Yarrhpelopia norrisi gen. n. sp. n. Larva. A. Head, left ventral, right dorsal: Abbreviations: S 5 - S 10 cephalic setae, DP—dorsal pit, VP—ventral pit: B. Segments 2 – 4 of antenna; C. Antennal apex; D. Mandible; E. Ligula; F. Palp; G. Submentum; H. Posterior parapod claws (selected).