Micronecta tasmanica Wróblewski, 1977

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 : 66-70

Micronecta tasmanica Wróblewski, 1977

( Figs. 38–40 )

Micronecta annae tasmanica Wróblewski, 1977: 685 .

Micronecta annae tasmanica: Cassis and Gross, 1995: 67 . [catalog]

Micronecta tasmanica: King, 1997: 151 . [species status]

Micronecta annae tasmanica: Lansbury and Lake, 2002: 3 , 32. [key; list]

Micronecta tasmanica: Andersen and Weir, 2004: 250 , 335. [key; list]

Diagnosis: Similar to M. robusta , but smaller and vertex distinctly produced in both sexes ( Figs. 38a–b ). Distinguished also by the unicolorous, light brown hemelytra ( Figs. 38a–b ) and unique form of the male parameres ( Figs. 40a–f ).

Size: ( Table 13). Macropterous form: 3.13–3.71. Brachypterous form not examined during this writing (see Wróblewski 1977).

Derivation of specific epithet: Named by Wróblewski honoring Tasmania, where the type series was collected .

Notes on type material: Wróblewski (1977) described Micronecta tasmanica from at least 274 specimens, however, he did not designate any type material. I was able to examine most specimens listed by Wróblewski in his original description [retained at ANIC], and from this material I designate the lectotype: (♂): “ Tasmania: Bronte Lagoon , ex trout guts, Dec. 1971. R. Beecroft ”. The lectotype is conserved in ANIC .

Description: Based on macropterous form. Measurements. Length: male 3.13–3.41; female 3.47–3.85; Width: male 1.46–1.55; female 1.57–1.76; Width of head: male 1.12–1.20; female 1.18–1.25; Synthlipsis: male 0.40–0.52; female 0.49–0.57; Width of eye: male 0.37–0.41; female 0.40–0.47; Width of pronotum: male 1.09–1.24; female 1.22–1.30; Length of pronotum: male 0.36–0.42; female 0.34–0.47.

Color: Ground color brown ( Figs. 38a–b ). Head light brown, eyes silvery-black. Vertex light brown with central reddish longitudinal line extending onto frons. Frons, clypeus, and genal areas light brown, genae with evenly distributed small pitting. Labium black. Antennae light brown, same color as head. Pronotum darker brown, unicolorous, outer apical portion darkened along entire width. Scutellum lighter brown, darker basally. Clavi each with broad pale, diagonal area well-developed, medial and apical portions same color as rest of hemelytra. Inner portion of each clavi often with longitudinal row of even spaced small black dots, numbering 11 to 13 ( Figs. 38a–b ). Corium sandy-brown, unicolorous. Prenodal embolar area long, infuscated, post-nodal embolar area short, infuscated. Left membrane in both sexes subhyaline, light brown to pale along inner margin. Venter of both sexes pale, light brown, natatorial setae of metatarsus darkened.

Structural characteristics: Ratio of body length/width: males 2.19; females 2.22. Head slightly narrower than pronotal width, synthlipsis 1.2 times as wide as posterior width of eye. Ocular index: males 1.34; females 1.61. General facies of head (vertex, frons, and labium) proportionate. Third antennal segment densely pilose, long, upper margin straight and lower margin rounded, apex broadly rounded, segments one and two very short. Pronotum robust, widest at middle with lateral margins weakly tapered and squared, about three times as wide as long (W/L: males 1.19/0.39; females 1.23/0.42). Prothoracic lobe short, broad, with lower and posterior lobes broadly rounded ( Fig. 39a ). Hemelytral microsculpturing consisting of dense, fine transverse meshes, particularly well-developed on each clavi. Short setae uniformly distributed over entire hemelytral surface, those of the apical claval portion and, on the right membrane longer, at least two times the length of the setae on the corium and basal portion of clavi. Metathoracic wings well-developed, reaching nearly to apices of hemelytra. 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: two stout, short setae, one long, thin seta; VII: two short, stout spines, one longer, stout spine; VIII: eight stout, short spines, three long, thin setae. Metaxyphus of both sexes broad, acutely triangular, apex narrowly rounded ( Fig. 39b ).

Male foreleg ( Fig. 39c ): femur with two short, stout spines in basal third near ventral surface. Tibia with one short spine in apico-ventral portion and one longer, thin seta placed apico-dorsally. Pala with three short setae and four to five spine-like setae dorsally; palmar area with 12–13 setae in upper row, 15–16 setae in lower row, lower row setae more pronounced than those of dorsal row. Apex of pala with a long thickened seta. Palar claw ( Fig. 39d ) tapered proximally, broad, and rounded apically. Female foreleg with same general setal arrangement as male. Mesotarsal claws equaling about one-half the length of the mesotarsus.

Lateral lobes of abdominal tergum IV comparatively broad, rounded apically. Right lobe slightly shorter, with 11 long setae, left lobe longer, with 14 long evenly spaced, apically placed setae. Prestrigilar flap of tergal segment V as in Figure 39e . Strigil well-developed, elongate and narrow, with few combs. Median lobe of sternite VII ( Fig. 39f ) long, with numerous setae of varying lengths restricted sub-basally, apex narrowly rounded. Free lobe of tergite VIII ( Fig. 39g ) broad, nearly triangular, outer angle broadly rounded and inner angle long, well-produced. Inner angle with about 20 long setae. Pars stridens processus cleaner ridges of tergite VIII not examined. Male left paramere ( Figs. 40a–c ) relatively short, shaft curved, as seen in ventral view ( Fig. 40c ), with medial portion parallel-sided. Apex of paramere with a flap-like process, seen best from inner view ( Figs. 40b–c ), in outer view ( Fig. 40a ), apex appearing sharply pointed. Scales present in apical third of paramere, base short and broad, lower portion broadly rounded ( Figs. 40a–c ). Right paramere ( Figs. 40d–e ) very long, parallel-sided, tip tapering abruptly to blunt point, appearing ‘goose-head’ in outline ( Fig. 40e ). Base long, widened, lower portion rounded, with about 22 plectral ribs confined to lower portion ( Fig. 40f ). Aedeagus broad.

Distribution and Habitat: AUSTRALIA: Tasmania, Victoria. The species is common throughout Tasmania, being collected from both lentic and lotic habitats. Exemplars have also been recovered from trout stomachs ( Wróblewski 1977, and see below). In Tasmania, I collected the species in association with Micronecta robusta , from a small, deep pond near a monoculture of Pinus radiata (monterey pine), and also from a boggy wooded swamp.

Discussion: A very distinct species, easily recognized by general facies and the distinct male genitalia. Contrary to Wróblewski’s (1977) comments on the species, M. tasmanica differs considerably from M. annae , not only in general habitus, but in all other examined characters. The stability seen in the general facies of M. tasmanica is quite remarkable, when compared to other species of the M. annae species group. The only variability seen was between lighter and darker forms (general ground color) of the species. All other morphology characters examined, including the unique form of the male left paramere ( Figs. 40a–c ) and the characteristic ‘goose head’ shape of the apex of the right paramere ( Figs. 40d–e ), were quite constant throughout numerous samples examined from Tasmania and Victoria.

Wróblewski (1977) noted examining only brachypterous forms, stating the mesothoracic wings were only slightly shorter than the hemelytra and wing muscles were highly reduced. All specimens examined during this writing were macropterous with fully developed mesothoracic wings and no indication of reduced flight muscles.

S pecimens examined: AUSTRALIA: Tasmania: Lake Eucumbene, Frying Pan Creek, ex trout. 6-IX-1969. E. F. Riek. (21♂, 25♀♀). [ ANIC]; Tasmania: Hobart Airport, Temporary Pond, Llanherne. 30-IX-1969. P. S. Lake. (8♂, 5♀♀). [ ANIC]; Tasmania: Arthurs Lakes, ex trout gut. (2♂, 2♀♀). [ ANIC]; Tasmania: Bruny Island , pond at Coal Point, 3 miles N Adventure Bay. 21-V-1970. P. S. Lake. (2♂, 5♀♀). [ ANIC]; Tasmania: (NW): Hellyer River Gorge. 9-II-1971. A. Neboiss. (1♂, 1♀). [ MVMA]; Tasmania: Bronte Lagoon, ex trout guts. XII-1971. R. Beecroft. (5♂, 24♀♀). [ ANIC]; Tasmania: Pine Tier Dam. 25-I-1972. B. Knott. (1♂, 1♀). [ ANIC]; Tasmania: Pawleena. 14-II-1972. Lake. T. Walker. (1♀). [ ANIC]; Tasmania: Melton Mowbray, River Jordan. 13-IV-1972. B. Knott. (6♂, 9♀♀). [ ANIC]; Tasmania: Lagoon of Islands. 16-IV-1972. B. Knott. (2♂, 4♀♀). [ ANIC]; Tasmania: Arthurs Lake , end of Flintstone Drive. 17-IV-1972. B. Knott. (5♂, 3♀♀). [ ANIC]; Tasmania: Pawleena, Small Lake . 23-IV-1972. T. Walker. (1♀). [ ANIC]; Tasmania: 4 miles N Richmond, Coal River , Laburnum Park. 26-V-1972. T. Walker. (2♂, 1♀). [ ANIC]; Tasmania: Pawleena, Small Lake , on upper reaches of Sorell River . 26-V-1972. T. Walker. (2♂, 4♀♀). [ ANIC]; Tasmania: Coal River at Richmond . 29-V-1972. T. Walker. (1♀). [ ANIC]; Tasmania: 4 miles N Richmond, Coal River , Laburnum Park. 23-VI-1972. T. Walker. (1♂). [ ANIC]; Tasmania: Llewellyn Lake . 25-VI-1972. A. Sheppard. (16♂, 11♀♀). [ ANIC]; Tasmania: Pawleena, Small Lake . 14-VII-1972. T. Walker. (2♂, 1♀). [ ANIC]; Tasmania: Pawleena, Small Lake , upper reaches of Sorrell River . 10-VIII-1972. T. Walker. (8♂, 36♀). [ ANIC]; Tasmania: Arthurs Lake . 29-VIII-1972. Shore. P. S. Lake & B. Knott. (14♂, 9♀♀). [ ANIC]; Tasmania: Pawleena, Small Lake . 9- IX-1972. T. Walker. (1♂, 4♀♀). [ ANIC]; Tasmania: Bruny Island , The Little Lagoon. 30-IX-1972. P. S. Lake & B. Knott. (1♀). [ ANIC]; Tasmania: Lagoon of Islands. 3-X-1972. R. Mawbey & B. Knott. (1♂, 7♀♀). [ ANIC]; Tasmania: Richmond , Coal River , Laburnum Park. 10-X-1972. (4♂, 6♀♀). ANIC ]; Tasmania: Pond at Talawah. 31-X-1972. B. Knott. (4♂, 3♀♀). [ ANIC]; Tasmania: Icena Lagoon. 1-XI-1972. R. Mawbey & B. Knott. (2♂, 3♀♀). [ ANIC]; Tasmania: Gladstone Lagoon. 2-XI-1972. B. Knott & R. Mawbey. (3♂). [ ANIC]; Tasmania: Pawleena, Small Lake. 2-XI-1972. T. Walker. (5♂). [ ANIC]; Tasmania: Scottsdale. 2-XI- 1972. R. Mawbey & B. Knott. (1♀). [ ANIC]; Tasmania: Three River Creek , King Island . 7-XII-1972. B. Knott. (1♂, 1♀). [ ANIC]; Tasmania: King Island , Lake Flanagan. 10-XII-1972. G. Best & B. Knott. (1♂). [ ANIC]; Tasmania: Coal River , Laburnum Park, 4 miles N Richmond. 15-I-1973. T. Walker. (1♀). [ ANIC]; Tasmania: Calder River . 6-II-1973. P. S. Lake & B. Knott. (1♂). [ ANIC]; Tasmania: Guide River Falls . 6-II-1973. P. S. Lake, B. Knott, R. Mawbey, & A. Richardson. (6♂, 6♀♀). [ ANIC]; Tasmania: Little Forester Lagoon, dry side. 13-VII-1973. B. Knott. (6♂, 5♀♀). [ ANIC]; Tasmania: Pipers River , 1.8 miles E Pipers River. 24-VII- 1973. T. Walker. (1♀). [ ANIC]; Tasmania: pond at old asbestos mine, near Beaconsfield. 24-VII-1973. (2♂, 1♀). [ ANIC]; Tasmania: 3.8 miles W Carrick, Whitemore Creek. 25-VII-1973. T. Walker. (1♀). [ ANIC]; Tasmania: Farm dam 2 miles N Holwell, Beaconsfield Road. 25-VII-1973. P. S. Lake. (1♂, 2♀♀). [ ANIC]; Tasmania: Bruny Island , small lagoon near mouth of Salt Water Creek . 18-IX-1973. R. B. Mawbey. (1♂). [ ANIC]; Tasmania: Mersey River at Merseylea. 5-XI-1973. B. Knott. (1♂, 2♀♀). [ ANIC]; Tasmania: Calder River . 6-XI-1973. P. S. Lake & B. Knott. (2♂, 1♀). [ ANIC]; Tasmania: 3 miles N Marrawahaon, Montague Creek. 9-XI-1973. P. S. Lake. (3♂). [ ANIC]; Tasmania: Copping Dam. 26-V-1974. W. Walker. (9♂, 25♀♀). [ ANIC]; Tasmania: Copping Dam C. 20-VII-1974. (31♂, 77♀♀). [ ANIC]; Tasmania: v605 gate N of Savage River Gorge on Savage River Pipeline. 11-V-1975. Roadside Pools. P. Richardson & P. Sutter. (1♀). [ ANIC]; Tasmania: Eugenana, Arboretum Lake . 29-IX-1986. L. Hill. (6♂, 9♀♀). [ ANIC]; Tasmania: Bakers Beach Lagoon , Asbestos Range National Park . 5-X-1986. L. Hill. (6♀♀). [ ANIC]; Tasmania: SW National Park, Maydena Access, Gordon River Road, 3.6 km NE of road. 42.80259 S 146.09252 E. 18-I-2004. Bog, dead wooded swamp. P. P. Tinerella. (2♀♀). [ PPTC]; Tasmania: 53.1 km S of Wynyard on Murchison Hwy. 41.30545 S 145.59042 E. 25-I-2004. Pond. P. P. Tinerella. (5♂, 12♀♀). [ PPTC]; Victoria: Buffalo Lake . 27-XI-1969. E. F. Riek. (18♂, 17♀♀). [ ANIC] .

Figures

FIGURE 38. Micronecta tasmanica Wróblewski. a. Male. b. Female. Scale bars = 0.5 mm.

FIGURE 39. Micronecta tasmanica Wróblewski. 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 40. Micronecta tasmanica Wróblewski, male genitalia. a. Left paramere, lateral aspect. b. Left paramere, lateral aspect of opposite face (cf Fig. a,c). c. Left paramere, ventral aspect. d. Right paramere, medio-lateral aspect. e. Right paramere, tip. f. Pars stridens processus, base of right paramere.