Austronecta australiensis ( Chen, 1965 ) Tinerella, 2013

Tinerella, Paul P., 2013, <strong> Taxonomic revision and systematics of continental Australian pygmy water boatmen (Hemiptera: Heteroptera: Corixoidea: Micronectidae) </ strong>, Zootaxa 3623 (1), pp. 1-121 : 7-12

Austronecta australiensis ( Chen, 1965) , comb. nov.

( Figs. 1–3 )

Micronecta australiensis Chen, 1965: 156 .

Micronecta australiensis: Wróblewski, 1972b: 519 . [description; list]

Micronecta australiensis: King, 1976: 35 . [stridulation]

Micronecta australiensis: Cassis and Gross, 1995: 67 . [catalogue]

Micronecta australiensis: Andersen and Weir, 2004: 250 . [key, list]

Diagnosis: Readily recognized by its small size, habitus ( Figs. 1a–d ), and distinct ribbon-like apex of the male left paramere ( Figs. 3d–e ). Similar in habitus to A. carinata and A. micra , separated from the former by hemelytral maculations ( Figs. 12b–d ) and from the latter by size and rounded hind margin of head ( Figs. 4a–b ).

Size: ( Table 2). Brachypterous form: 2.03–2.33 mm. Macropterous form: 2.48–2.62 mm.

Derivation of specific epithet: Named honoring Australia, as the type series was collected in the ‘Federal Capital Territory’ (=Australian Capital Territory-ACT) ( Chen 1965).

Notes on type material: Chen listed depositing the holotype (♂), allotype (♀), and 34 paratypes in SEMC, and six paratypes in SAMA. Holotype: (♂) “ Federal Capital Territory (near Canberra ), Australia. 25-III-1931. J. Evans. ” [ SEMC]; Allotype and Paratypes: (labeled with blue label each printed as PARATYPE; Micronecta australiensis L. C. Chen ): “Federal Capital Territory (near Canberra), Australia. 25-III-1931. J. Evans. ” (16♂, 19♀♀). [ SEMC]; “Alexandra, Victoria. F. L. Billinghurst. ” (1♂). [ SEMC]. I have examined the holotype and nine paratypes (4♂, 5♀♀). Six paratypes (3♂, 3♀♀) listed by Chen (1965) as deposited in SAMA were not verified or examined. I examined five paratypes: “Federal Capital Territory (near Canberra), Australia. 25-III-1931. J. Evans. ” (2♂, 3♀♀) from ANIC. Type material not illustrated .

Description: Based on brachypterous form. Three macropterous specimens examined and noted below as [macropterous]; measurement data are included in Table 2. Measurements. Length: male 2.04–2.18 [2.62–2.63]; female 1.91–2.18 [2.48]; Width: male 1.16–1.22 [1.20–1.24]; female 1.09–1.18 [1.23]; Width of head: male 0.80–0.88 [0.91–0.94]; female 0.77–0.86 [0.90]; Synthlipsis: male 0.35–0.44 [0.45–0.47]; female 0.33–0.37 [0.47]; Width of eye: male 0.20–0.25 [0.26–0.29]; female 0.20–0.23 [0.29]; Width of pronotum: male 0.77–0.78 [1.03–1.04]; female 0.65–0.79 [1.03]; Length of pronotum: male 0.11–0.17 [0.34–0.35]; female 0.15–0.17 [0.21].

Color: Ground color light brown ( Figs. 1a–d ). Head same color, eyes red or silvery-black. Frons with central reddish-brown pubescent area, clypeal regions and vertex lighter, clypeogenal area evenly and densely pitted, darker brown in females, same color as vertex in males. Labium black. Third antennal segment dark brown. Pronotum brown, lighter in apical and basal portions, with pale narrow transverse band apically, spanning width. Scutellum short, same color as pronotum. Hemelytra darker brown, basal portion of each clavus with broad diagonal pale area. Corium generally unicolorous with restricted darker areas along latero-medial margin. Macropterous form with latero-medial dark coloration expanded on corium. Dense, linear microsculpturing, trending longitudinal, produced on clavi, microsculpturing less dense over corium. Prenodal embolar area welldeveloped, infuscated, post-nodal embolar area indistinct although darkened. Pale, narrow longitudinal stripe present anterior to right membrane. membrane. Right membrane coriaceous, left membrane sub-hyaline and infuscated. Abdomen infuscate, lateral margins paler. Mesotibia and mesotarsus with dark apical ring.

Structural characteristics: Ratio of body length/width: males 1.94; females 1.83. Head, on average, slightly narrower than pronotal width, synthlipsis 1.7 times as wide as posterior width of eye. Ocular index: males 1.80; females 1.67. General facies of head (vertex, frons, and labium) short. Third antennal segment densely pilose, long, elliptical, with apex broadly rounded; segments one and two very short. Pronotum very short in brachypters ( Figs. 1a–b ), tapering laterally, apical margin nearly straight. Pronotum in macropterous form ( Figs. 1c–d ) elliptical, widened medially and tapering laterally. Pronotum in brachypters averaging six times as wide as long (W/L: males 0.78/0.13; females 0.79/0.16). In macropters, pronotum considerably larger, proportionate, averaging three to four times as wide as long (W/L: males 1.04/0.35; females 1.03/0.21). Prothoracic lobe narrowed and long ( Fig. 2a ), anterior margin straight, posterior and lower margins rounded. Hemelytra with dense linear microsculpturing especially produced on the clavi. Hemelytral setae robust and uniformly distributed. Surface of head with dense microsculpturing, pronotum with ill-developed pitting, hemelytra more or less smooth. Lateral spines on abdominal segments IV–VIII: IV: one stout, short spine, two thin, long setae; V: two stout, short setae, one long, stout seta, one long, thin seta; VI: three stout, short setae, one long, thin seta; VII: five short, stout spines, one longer, stout spine; VIII: five stout, short spines, two long, thin setae. Metaxyphus of both sexes short, broad, acutely triangular, apex acuminate ( Fig. 2b ).

Male foreleg ( Fig. 2c ): femur with two short, stout spines in basal third near ventral surface, two additional spines near ventral surface of base. Tibia with two longer spines in apico-dorsal portion and one short spine near apico-ventral surface. Pala with four long setae dorsally; palmar area with 14–15 ill-developed setae in upper row, 17–18 setae in lower row. Apex of pala with a short thickened seta. Palar claw ( Fig. 2d ) elongate, broadest medially, apex rounded. Female foreleg with same general setal arrangement as male. Mesotarsal claws short, equaling about one-fifth the length of the mesotarsus.

Lateral lobes of abdominal tergum IV comparatively broad, rounded apically. Right lobe slightly broader and longer, with 13–16 long setae, left lobe shorter, with 6–8 long evenly spaced, apically placed setae. Prestrigilar flap of tergal segment V as in Figure 2e . Strigil very small, elongate and elliptical, with few combs. Median lobe of sternite VII ( Fig. 2f ) short, broad, with four longer setae restricted sub-basally, apex acuminate. Free lobe of tergite VIII ( Fig. 2g ) broad, nearly quadrate with inner angle rounded. Inner angle with 16–18 setae of varying lengths. Pars stridens processus cleaner ridges of tergite VIII not examined. Male left paramere ( Figs. 3d–e, g ) short, shaft curved and parallel-sided, apical portion reduced and ribbon-like ( Figs. 3d–e ). Paramere base broad, hatchetshaped, lower portion of base broadly rounded ( Figs. 3d, g ). Right paramere ( Figs. 3d–g ) long, parallel-sided, tip tapering to bluntly rounded point ( Fig. 3e ). Base of right paramere long, lower portion rounded, with about 33–36 plectral ribs confined to medial portion ( Fig. 3h ). Aedeagus broad, as in Figures 3d–g .

Distribution and Habitat: AUSTRALIA: Australian Capital Territory, New South Wales, Queensland, Victoria. Widespread and abundant throughout lentic and lotic habitats in New South Wales, as seen from recent (late 1990s) survey material from AMSA (AMBS – Australian Museum Business Service Invertebrate Survey). The three macropterous specimens were collected from a river’s edge, in association with the brachypterous form. The species is previously unrecorded from Queensland; the far north records (Babinda, QLD) indicating a much wider range in eastern Australia.

Discussion: The macropterous form of Austronecta australiensis was previously unknown. The encountered low frequency of the macropterous form from the material examined suggests the long wing form is uncommon. The macropterous forms examined appear very different from the brachypter and upon my first examination required dissection of the male genitalia. The dissection confirmed the identity of A. australiensis , and all other diagnostic characters, excepting the short pronotum, were identical to the brachypterous form.

Within the genus, A. australiensis is a distinct, easily recognized species. The species is sympatric with A. carinata in New South Wales and could be confused with smaller individuals of that species (see discussion under A. carinata ).

Specimens examined: AUSTRALIA: New South Wales: Little Dandahra Creek, Mulligan’s Hut. 29 31 02S; 152 21 33E. 28-IX-1994. Edge. Eren Turak. (1♂). [ AMSA]; same data. 30-IX-1994. Edge. Frances Laurenson. (1♂, 4♀♀). [ AMSA] ; New South Wales: Chalkhill’s Creek . 36 54 18S; 149 47 41E. 14-X-1994. Edge. Joanne Ling. (1♀). [ AMSA] ; New South Wales: Polack’s Flat Creek . 36 38 04S; 149 35 37E. 14-X-1994. Riffle. Joanne Ling. (1♀). [ AMSA] ; New South Wales: Towamba River, Burragate. 36 59 37S; 149 36 29E. 15-X-1994. Edge. Eren Turak. (3♀♀). [ AMSA]; same data. 15-X-1994. Riffle. Eren Turak. (2♂). [ AMSA] ; New South Wales: Towamba River, Coolangubra. 26 53 48S; 149 27 36E. 16-X-1994. Edge. Eren Turak. (5♀♀). [ AMSA] ; New South Wales: Wog Wog River, Lett’s Mountain . 37 04 04S; 149 31 22E. 16-X-1994. Edge. Joanne Ling. (3♂). [ AMSA] ; New South Wales: Wog Wog River, Nalbaugh. 37 01 53S; 149 26 29E. 16-X-1994. Edge. Joanne Ling. (2♂, 3♀♀). [ AMSA] ; New South Wales: Yadboro River . 35 19 12S; 150 10 44E. 13-III-1995. Edge. Eren Turak. (3♂, 3♀♀). [ AMSA] ; New South Wales: Towamba River, Coolangubra. 36 53 28S; 149 27 36E. 14-III-1995. Edge. Marie Eggerup. (1♂, 1♀). [ AMSA] ; New South Wales: Yadboro River u/s Budawang National Park . 35 18 54S; 150 08 19E. 14-III-1995. Edge. Eren Turak. (1♀). [ AMSA] ; New South Wales: Myanba Creek . 36 57 02S; 149 28 43E. 15-III-1995. Edge. Joanne Ling. (2♂, 3♀♀). [ AMSA] ; New South Wales: Towamba River, Burragate. 36 59 37S; 149 36 29E. 15-III-1995. Edge. Marie Eggerup. (15♂, 6♀♀). [ AMSA] ; New South Wales: Imlay Creek, Wallaraugh River . 37 14 02S; 149 41 49E. 16-III-1995. Edge. Eren Turak. (1♀). [ AMSA] ; New South Wales: Wog Wog River, Lett’s Mountain . 37 04 04S; 149 31 22E. 16-III-1995. Edge. Eren Turak. (3♀♀). [ AMSA] ; New South Wales: Wog Wog River, Nalbaugh. 37 01 53S; 149 26 29E. 16-III-1995. Edge. Eren Turak. (1♀). [ AMSA] ; New South Wales: Rocky Bridge Creek u/s Piesley’s Creek . 33 51 33S; 149 08 14E. 24-III-1995. Edge. Russell Cowell. (1♂). [ AMSA] ; New South Wales: Little Dandahra Creek, Mulligan’s Hut. 29 31 02S; 152 21 33E. 11-V-1995. Edge. Joanne Ling. (25♂, 31♀♀). [ AMSA] ; New South Wales: Nepean River u/s Penrith. 33 48 12S; 150 37 36E. 26-V-1995. Edge. Frances Laurenson. (1♂). [ AMSA] ; New South Wales: Shoalhaven River, Yalwal Creek . 34 49 38S; 150 23 12E. 1-VI-1995. Edge. Joanne Ling. (1♂, 5♀♀). [ AMSA] ; New South Wales: Little Dandahra Creek, Mulligan’s Hut. 29 31 02S; 152 21 33E. 9-X-1995. Edge. Joanne Ling. (3♂, 2♀♀). [ AMSA] ; New South Wales: Cataract River at Sandy Hill. 28 55 33S; 152 13 31E. 10-X-1995. Riffle. Joanne Ling. (1♀). [ AMSA] ; New South Wales: Corall’s Creek at Bald Rock National Park . 28 50 51S; 152 05 54E. 11-X-1995. Edge. Joanne Ling. (5♂, 3♀♀). [ AMSA] ; New South Wales: Towamba River, Coolangubra. 36 53 28S; 149 27 36E. 24-X-1995. Natacha Waddell. (6♂, 3♀♀). [ AMSA] ; New South Wales: Mumbulla Falls . 36 34 31S; 149 53 20E. 25-X-1995. Edge. Eren Turak. (3♀♀). [ AMSA] ; New South Wales: Murrah River, Knight’s Creek . 36 32 50S; 149 58 50E. 25-X-1995. Edge. Eren Turak. (6♂, 20♀♀). [ AMSA] ; New South Wales: Towamba River, Burragate. 36 59 37S; 149 36 29E. 25-X-1995. Edge. Russell Cowell. (14♂, 13♀♀). [ AMSA] ; New South Wales: Jingo Creek . 36 59 31S; 149 39 35E. 26-X-1995. Edge. Russell Cowell. (2♀♀). [ AMSA] ; New South Wales: Watergums Creek, Wonboyn River . 36 17 03S; 149 52 47E. 26-X-1995. Edge. Joanne Ling. (1♀). [ AMSA] ; New South Wales: Imlay Creek, Wallaraugh River . 37 14 02S; 149 41 49E. 27-X-1995. Edge. Alexander Leask. (3♀♀). [ AMSA] ; New South Wales: Murray River d/s W Albury Sewage Plant. 36 04 27S; 146 52 12E. 9-XI- 1995. Edge. Joanne Ling. (1♀). [ AMSA] ; New South Wales: Tuena Creek d/s Bears Gully. 34 04 28S; 149 22 08E. 14-XI-1995. Edge. Russell Cowell. (1♀). [ AMSA] ; New South Wales: Murray River u/s Indi Bridge. 36 14 15S; 148 02 02E. 22-XI-1995. Edge. Alexander Leask. (1♂, 1♀). [ AMSA] ; New South Wales: Stony Creek . 35 39 26S; 147 45 32E. 22-XI-1995. Edge. Natacha Waddell. (1♂, 2♀♀). [ AMSA] ; New South Wales: Yadboro River . 35 19 12S; 150 10 44E. 22-XI-1995. Edge. Eren Turak. (1♂, 1♀). [ AMSA] ; New South Wales: Shoalhaven River, Fossicker’s Flat. 34 49 16S; 150 11 32E. 5-XII-1995. Edge. Joanne Ling. (3♂, 3♀♀). [ AMSA] ; New South Wales: Broger’s Creek . 34 42 02S; 150 41 11E. 12-XII-1995. Edge. Alexander Leask. (6♀♀). [ AMSA] ; New South Wales: Wallagarough River . 37 15 21S; 149 39 42E. 4-III-1996. Edge. Joanne Ling. (3♂, 5♀♀). [ AMSA] ; New South Wales: Mataganah Creek . 36 52 45S; 149 38 53E. 5-III-1996. Joanne Ling. (1♂). [ AMSA] ; New South Wales: Towamba River, Burragate. 36 59 37S; 149 36 29E. 5-III-1996. Edge. Joanne Ling. (5♂, 4♀♀). [ AMSA] ; New South Wales: Jingo Creek . 36 59 31S; 149 39 35E. 6-III-1996. Edge. Joanne Ling. (1♀). [ AMSA] ; New South Wales: Myanba Creek . 36 57 02S; 149 28 43E. 6-III-1996. Joanne Ling. (3♂, 9♀♀). [ AMSA] ; New South Wales: Watergums Creek, Wonboyn River . 36 17 03S; 149 52 47E. 8-III-1996. Edge. Eren Turak. (1♂, 1♀). [ AMSA] ; New South Wales: Lachlan River d/s Humes Creek . 33 44 31S; 149 17 50E. 18-III-1996. Edge. Joanne Ling. (9♂, 6♀♀). [ AMSA] ; New South Wales: Murray River, Jingellic. 35 55 54S; 147 42 06E. 19-III-1996. Edge. Natacha Waddell. (1♂). [ AMSA] ; New South Wales: Abercrombie River u/s Isabella River . 34 01 56S; 149 29 48E. 20-III-1996. Edge. Adam McLean. (1♂, 5♀♀). [ AMSA] ; New South Wales: Little Dandahra Creek, Mulligan’s Hut , CLAR 14. 29 31 02S; 152 21 33E. 14-IV-1996. Edge. Joanne Ling. (8♂, 5♀♀). [ AMSA] ; New South Wales: Shoalhaven River, Fossicker’s Flat. 34 49 16S; 150 11 32E. 15-V-1996. Edge. Eren Turak. (3♀♀). [ AMSA] ; New South Wales: Corang River at Hockeys. 35 09 22S; 150 01 50E. 22-V-1996. Edge. Eren Turak. (4♀♀). [ AMSA] ; New South Wales: Upper Corang River. 35 12 19S; 150 03 02E. 22-V-1996. Edge. Eren Turak. (2♂, 3♀♀). [ AMSA] ; New South Wales: EPA Survey MRHI, Merrica River at Rangers Station , TOWA 705. 37 18 23S; 149 55 28E. 20-III-1997. Edge. Natacha Waddell. (1♂, 1♀). [ AMSA] ; New South Wales: EPA Survey MRHI, Murray River - Tom Groggin , MURR 24. 36 32 52S; 148 07 34E. 21-III-1997. Edge. Alexander Leask. (1♀). [ AMSA] ; New South Wales: EPA Survey MRHI, Myanba Creek , TOWA 09. 36 57 02S; 149 28 43E. 22-III- 1997. Edge. Natacha Waddell. (2♂, 3♀♀). [ AMSA] ; New South Wales: EPA Survey MRHI, Towamba River at Towamba , TOWA 502. 37 05 02S; 149 41 40E. 22-III-1997. Edge. Eren Turak. (2♂). [ AMSA] ; New South Wales: Kangaroo River d/s Hampton Bridge , SHOA 503. 34 43 43S; 150 31 11E. 26-III-1997. Edge. Alexander Leask. (1♂, 1♀). [ AMSA] ; New South Wales: Shoalhaven River, Fossicker’s Flat , SHOA 05. 34 49 16S; 150 11 32E. 11-VI-1997. Edge. Alexander Leask. (3♂, 6♀♀). [ AMSA] ; New South Wales: EPA Survey MRHI, Myanba Creek , TOWA 10. 36 57 02S; 149 28 43E. 24-X-1997. Edge. Eren Turak. (1♂). [ AMSA] ; New South Wales: Kangaroo River up Gerrigong Creek . 34 14 17S; 150 35 58E. 30-IV-1998. Edge. T. Rankin. (1♂, 1♀). [ AMSA] ; New South Wales: Shoalhaven River, Fossicker’s Flat. 34 49 16S; 150 11 32E. 30-IV-1998. Edge. Natacha Waddell. (2♂, 5♀♀). [ AMSA] ; New South Wales: EPA Survey MRHI, Myanba Creek , TOWA 09. 36 57 02S; 149 28 43E. 13-XI-1998. Edge. Eren Turak. (3♂, 1♀). [ AMSA] ; New South Wales: Hawkesbury-Nepean River System, N 626. 28-I-1999. Edge. Ecology Lab. (1♂, 1♀). [ AMSA] ; New South Wales: Hawkesbury-Nepean River System, N 627. 20-V-1999. M. F., M. G., S. W. (6♂, 7♀♀). [ AMSA] ; New South Wales: Hawkesbury-Nepean River System (non-tidal). 33 24 20S; 150 41 39E. 22-IX-1999. Edge. Ecology Lab. (2♂, 1♀). [ AMSA] ; New South Wales: Hawkesbury-Nepean River System, Georges River . 34 04 54S; 150 51 14E. 22-IX-1999. Edge. Ecology Lab. (1♀). [ AMSA] ; New South Wales: Hawkesbury-Nepean River System (junction). 33 36 39S; 150 41 47E. 23-IX-1999. Edge. Ecology Lab. (7♂, 3♀♀). [ AMSA] ; New South Wales: Hawkesbury-Nepean River System River, Gauge Grose River . 33 37 12S; 150 38 01E. 23-IX-1999. Edge. Ecology Lab. (10♂, 5♀♀). [ AMSA] ; New South Wales: Hawkesbury-Nepean River System u/s Broughton’s Pass. 34 13 49S; 150 44 34E. 27- IX-1999. Edge. Ecology Lab. (2♀♀). [ AMSA] ; New South Wales: Hawkesbury-Nepean River System, Jack Evan’s Track. 33 50 52S; 150 34 29E. 29-IX-1999. Edge. Ecology Lab. (5♂, 1♀). [ AMSA] ; New South Wales: Hawkesbury-Nepean River System, Pheasant’s Nest. 34 14 40S; 150 39 56E. 29-IX-1999. Edge. Ecology Lab. (3♀♀). [ AMSA] ; New South Wales: Hawkesbury-Nepean River System, Douglas Park. 34 11 42S; 150 42 38E. 6- X-1999. Edge. Ecology Lab. (1♀). [ AMSA] ; Queensland: Babinda. VII-1943. J. G. Brooks. (1♂, 2♀♀). [ AMSA] ; Queensland: Broken River, Eungella. 10-XII-1961. McAlpine & Lossin. (5♂, 4♀♀). [ AMSA] ; Victoria: Buffalo River, Dandongadale. 12-IV-1972. A. Neboiss. (13♂, 4♀♀). [ MVMA] ; Victoria: Dartmouth Survey, Dartmouth River . 2-III-1973. Melb. Uni. Bot. (1♂). [ MVMA] .

Figures

FIGURE 1. Austronecta australiensis (Chen), dorsal habitus. a–b. Brachypterous form. a. Male. b. Female. c–d. Macropterous form. c. Male. d. Female. Scale bars = 0.5 mm.

FIGURE 2. Austronecta australiensis (Chen). a. Prothoracic lobe, female. b. Metaxyphus. c. Left male foreleg, posterior aspect. d. Left male pala (tarsus), anterior aspect, palar claw folded in. e. Prestrigilar flap of abdominal segment V. f. Sternal process of abdominal segment VII. g. Free lobe of abdominal tergum VIII. Scale bars = 0.1 mm.

FIGURE 3. Austronecta australiensis (Chen). a. Metaxyphus. b. Left male pala (tarsus), anterior view, palar claw folded in. c. Sternal process of abdominal segment VII. d. Left paramere, lateral aspect, right paramere, dorso-lateral aspect. e. Left paramere, tip, right paramere, tip. f. Right paramere, lateral aspect. g. Left paramere, medio-ventral aspect, right paramere, dorso-lateral aspect. h. Pars stridens processus, base of right paramere.

FIGURE 4. Austronecta micra (Kirkaldy). a. Male. b. Female. Scale bars = 0.5 mm.

FIGURE 12. Austronecta carinata (Chen), paratype and dorsal habitus. a. Locality and type labels. b. Paratype specimen, female, dorsal habitus. c. Male. d. Female. Scale bars = 0.5 mm.