Micronecta virgata Hale, 1922

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 : 91-96

Micronecta virgata Hale, 1922

( Figs. 49–52 )

Micronecta virgata Hale, 1922: 327 .

Micronecta virgata: Lundblad, 1933: 76 . [list]

Micronecta virgata: Wróblewski, 1962b: 320 . [redescription]

Micronecta virgata: Chen, 1965: 164 . [faunistics]

Micronecta virgata: Wróblewski, 1970: 691 . [additional description]

Micronecta virgata: Cassis and Gross, 1995: 69 . [catalog]

Micronecta virgata: Nieser and Chen 1999: 82 . [additional diagnosis]

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

Micronecta virgata: Tinerella and Polhemus, 2005: 187 . [key; faunistics]

Micronecta virgata: Chen et al., 2005: 420 . [list]

Micronecta virgata: Tinerella, 2006a: 700 . [phylogeny discussion]

Micronecta virgata: Tinerella, 2008: 53 . [redescription, phylogeny]

Diagnosis: Readily distinguished by size, the interocular space greater than width of eye, and hemelytral patterning ( Figs. 49c–e ). Similar in general habitus to Micronecta carbonaria , however, the species is distinguished by the four distinct, longitudinal hemelytral stripes and by a combination of the characters given below.

Size: ( Table 16). Macropterous form: 2.89–3.50. The given metrics expand the previous known size for the species. Brachypterous form unknown.

Derivation of specific epithet: From the Latin virgata , meaning striped, probably referring to the blackstriped hemelytra of this species.

Notes on type material: Type series deposited in SAMA. Holotype ( Figs. 49a–c ): SAMA I.15190, ♂, “Townsville, G. F. Hill, N. Q.”, mounted on point card. Label bearing “TYPE”, as well as a handwritten label bearing “ Micronecta virgata Hale , Queensland ”; “TYPE” handwritten in red on right side of label. “I.15190” handwritten at top-right corner of label. Paratypes: (1♂, 1♀), SAMA. (♂): mounted on point card; “ Cairns Dist., A. M. Lea. ” Pin with pink “Co-Type” label. Large handwritten label printed “ paratype ” at right edge. Handwritten: “ Micronecta virgata Hale. ” (♀): mounted on point card; printed: “ Cairns Dist. , A. M. Lea. ” Pin with pink “Co- Type” label. Determination label bearing: Micronecta virgata Hale , det. L. C. Chen, 1962. All type material listed here was examined .

Description: Based on macropterous form. Measurements. Length: male 2.94–3.36; female 2.89–3.50; Width: male 1.51–1.61; female 1.66–1.75; Width of head: male 1.15–1.27; female 1.19–1.33; Synthlipsis: male 0.49–0.57; female 0.55–0.65; Width of eye: male 0.29–0.38; female 0.29–0.39; Width of pronotum: male 1.08–1.22; female 1.14–1.27; Length of pronotum: male 0.36–0.40; female 0.36–0.40.

Color: Ground color brown to reddish-brown ( Figs. 49c–e ). Head same color, eyes greyish-brown. Vertex and frons pale brown, clypeus darker brown, appearing mottled. Labium darker brown. Genal area lighter brown, same general color as head. Antennae pale. Pronotum dark brown, margins lighter, faint, narrowed pale band present along apical margin. Scutellum pruinose medio-laterally. Clavus with basal pale, diagonal area, apical portion same general ground color as corium and membrane. Corium with four darker contiguous, longitudinal bands present, though sometimes faint. Prenodal embolar area entirely pruinose. Postnodal embolar area very short, pruinose. Left membrane hyaline in both sexes, paler laterally, with inner portion embrowned, medio-apical portion with narrowed, darkened band present. Venter light brown, natatorial setae darker brown.

Structural characteristics: Ratio of body length/width: males 1.96; females 1.91. Head slightly wider than pronotum, interocular space greater than width of eye, synthlipsis 1.7 times as wide as posterior width of eye. Ocular index: males 1.56; females 1.74. General facies of head (vertex, frons, and labium) proportionate. Antennae densely pilose, segments one and two very short, segment three longer, club-shaped. Pronotum robust, convexly rounded and short, nearly four and one half times as wide as long (W/L: males 1.59/0.37; females 1.70/0.38). Prothoracic lobe broad, anterior margin quadrate, posterior margin broadly rounded ( Fig. 50a ). Hemelytra with short, transverse microsculpturing. Short setae distributed mainly over corium with setation of the clavus restricted to apical portions. Prenodal embolar area well-developed, nodal furrow and postnodal embolar area similar to Micronecta carbonaria Horváth. Metathoracic wings well-developed, reaching to apices of hemelytra. Lateral spines on abdominal segments IV–VIII: IV: one stout, short spine, one long, thin spine; V: two short, stout spines, one long, stout spine, one long, thin spine; VI: two short, stout spines, one long, stout spine; VII: two short, stout spines, one long, stout spine; VIII: four stout, short spines, three thin, long spines. Metaxyphus of both sexes short, triangular, acutely pointed ( Fig. 50b ).

Male foreleg ( Fig. 50c .): femur with two short, stout spines in basal third near ventral surface, a cluster of four to six stout spines basally, and two spines, one stout, long spine and one shorter, thin spine, placed medially on dorsal surface. Tibia with one large latero-ventral spine in anterior portion and one large spine dorso-apically. Pala with four to five larger setae dorsally; palmar area with nine setae in dorsal row and 13–15 in ventral row, ventral row setae more pronounced than dorsal row. Apex of pala with single thickened, claw-like seta. Palar claw ( Fig. 50d ) tapered sharply proximad, widening with upper surface broadly rounded, lower margin nearly straight. Female foreleg with same general setal arrangement as male. Mesotarsal claws long, nearly three-fourths the length of mesotarsus.

Lateral lobes of abdominal tergum IV short, rounded. Right lobe with 16 long setae along margin, left lobe with 13 setae evenly spaced along margin. Prestrigilar flap of tergal segment V short and wide, with margins rounded ( Fig. 50e ). Strigil very long, rectangular in outline, width variable though never wider than long. Median lobe of sternite VII ( Fig. 51a ) short, length nearly equal to width, apex acutely pointed, setal lengths variable and confined to extreme basal portion. Free lobe of tergite VIII ( Fig. 51b ) broad, with well-produced rounded inner angle, setae restricted to upper inner angle and apex, numbering 11 to 16. Pars stridens processus cleaner ridges of tergite VIII appearing as a fine-ridged mat, with upper narrow series and broad lower widened series. Left paramere ( Figs. 51c–f ) markedly shorter than right, shaft equally broad along length with sharp, recurved distal hook. Base short, broadly rounded. Right paramere ( Figs. 51c–g ) with long medially constricted shaft, apex broad and sharply pointed. Base broad ( Fig. 51h ) with 28–36 plectral ribs spanning width. Aedeagus, as in Figures 51c–g .

Distribution and Habitat: ( Fig. 52 ). A widespread species, known from Sulawesi, Timor, Australia, New Guinea, and the Solomon Islands ( Tinerella 2006b). In Australia, the species is distributed in the north from Queensland and Northern Territory, westward to Western Australia. The species is newly recorded here from Northern Territory. No Queensland records (except the type series) were examined in this writing. Little habitat data are available for the species. Most specimens examined in this writing were taken at lights.

Discussion: Micronecta virgata is clearly allied with M. carbonaria and other species of the M. annae species group on the basis of abdominal morphology and the male genitalia. Variation within the species was discussed by Tinerella (2006b, 2008).

Specimens examined: AUSTRALIA: Northern Territory: Darwin. swamp. CL-903. 10-XII-1977. J. T. Polhemus. (2♀♀). [ JTPC] ; Northern Territory: Daly River . CL-906. 11-XII-1977. J. T. Polhemus. (3♂, 2♀♀). [ JTPC] ; Northern Territory: S. Alligator River area , 35 km W Jabiru. blacklight. 9-IV-1980. G. F. Hevel and J. A. Fortin. (39♂, 117♀♀). [ USNM] ; Western Australia: GPS Karajini N. P., 17 km W of Ranger Station. 22.35S; 118.17E. at light, open forest. 20-IV-2003. T. A. Weir. (6♂, 16♀♀). [ ANIC] ; Western Australia: Pilbara, Paradise Pool. PSW034. 3-IX-2003. J. M. McRae. (18♂, 23♀♀). [ CALM] .

Figures

FIGURE 49. Micronecta virgata Hale, holotype and dorsal habitus. a–b. Locality and type labels. c. Holotype specimen, male, dorsal habitus. d. Male. e. Female. Scale bars = 0.5 mm. (modified from Tinerella, 2008)

FIGURE 50. Micronecta virgata Hale. 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. Scale bars = 0.1 mm. (modified from Tinerella, 2008)

FIGURE 51. Micronecta virgata Hale, male terminalia. a. Sternal process of abdominal sternite VII. b. Free lobe of abdominal tergite VIII. c. Left paramere, lateral aspect, right paramere, dorso-lateral aspect. d. Left paramere, dorso-lateral aspect. e. Left paramere, dorso-lateral aspect (cf base Fig. c,d,f). f. Left paramere, ventro-medial aspect, right paramere, dorso-lateral aspect. g. Right paramere, tip. h. Pars stridens processus, base of right paramere. (modified from Tinerella, 2008)

FIGURE 52. Australian distribution of Micronecta virgata Hale.