Micronecta quadristrigata Breddin, 1905

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 : 102-108

Micronecta quadristrigata Breddin, 1905

( Figs. 57–60 )

? Sigara lineata Fieber, 1844: 15 . (junior secondary homonym of Notonecta lineata Forster, 1771 ; primary junior homonym of Sigara lineata Fabricius, 1787 ; junior secondary homonym of Corixa lineata Rambur, 1840 ) [suspected synonymy Wróblewski, 1968: 776]

? Sigara m-notata Kirkaldy, 1897b: 240. (replacement name for Sigara lineata Fieber, 1844 ) [nomen oblitum]

Micronecta quadristrigata Breddin, 1905a: 57 .

Micronecta quadristrigata: Breddin, 1905b: 157 . [description; key]

Micronecta minthe Distant, 1910: 347 . [synonymy Wróblewski, 1968: 776; see below and discussion]

Micronecta quadristrigata: Bergroth, 1918: 126 . [distribution]

Micronecta quadristrigata: Dover, 1928: 72 . [note]

Micronecta quadristrigata: Lundblad, 1933: 87 . [redescription]

Micronecta minthe: Lundblad, 1933: 87 . [synonymy]

Micronecta quadristrigata: Hutchinson, 1940: 376 . [distribution]

Micronecta quadrisignata [sic]: Fernando, 1960: 184. [life history]

Micronecta quadristrigata: Chen, 1960: 103 . [key]

Micronecta quadristrigata: Wróblewski, 1960a: 301 . [additional description; distribution]

Micronecta quadristrigata: Wróblewski, 1962a: 176 . [notes; Sigmonecta , subg. n.]

Micronecta quadristrigata: Fernando and Leong, 1963: 549 . [life history; biology]

Micronecta quadristrigata: Fernando, 1964: 609 . [diagnosis; faunistics]

Micronecta quadristrigata: Chen, 1965: 164 . [description; phylogenetic relationships]

Micronecta quadristrigata: Miyamoto, 1965: 489 . [faunistics]

Micronecta quadristrigata: Leong, 1966: 85 . [key; faunistics]

Micronecta quadristrigata: Wróblewski, 1967: 237 . [faunistics]

Micronecta quadristrigata: Wróblewski, 1968: 771 . [faunistics; synonymical list]

Micronecta quadristrigata: Wróblewski, 1970: 697 . [diagnosis; key]

Micronecta quadristrigata: Wróblewski, 1972a: 29 . [description]

Micronecta quadristrigata form minthe: Wróblewski, 1972a: 33 . [lectotype designation]

Micronecta quadristrigata: Wróblewski, 1972b: 524 . [list]

Micronecta quadristrigata: Fernando and Cheng, 1974: 38 . [faunistics]

Micronecta quadristrigata: Nieser and Chen, 1992: 35 . [faunistics]

Micronecta quadristrigata: Jansson, 1995: 34 . [catalogue]

Micronecta quadristrigata: Cassis and Gross, 1995: 69 . [catalogue]

Micronecta quadristrigata: Nieser, 1999b: 286 . [key]

Micronecta quadristrigata: Nieser and Chen, 1999: 80 . [faunistics; key]

Micronecta quadristrigata: Nieser, 2002b: 269 . [notes; key]

Micronecta qudristrigata [sic]: Andersen and Weir, 2004: 250. [key; list]

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

Sigara m-notata: Tinerella, 2008: 39. [nomen oblitum]

Micronecta quadristrigata: Tinerella, 2008: 39 . [nomen protectum; redescription, phylogeny]

Diagnosis: This widespread, highly variable species is readily identified by the widened interocular space ( Figs. 57a–b ), distinctive free lobe of tergite VIII ( Figs. 58f , 59b ), and male parameres ( Figs. 59c–h ). Females are distinguished by general dorsal facies ( Fig. 57b ), prothoracic lobe ( Fig. 58a ), and metaxyphus ( Fig. 58b ).

Size: ( Table 18). Macropterous form: 2.51–2.90. Wróblewski (1970) reported females up to 3.22 mm. Derivation of specific epithet: From the Latin combination quadri-, meaning four and - strigata, meaning streak, probably in reference to the four dark longitudinal, often incomplete lines on the corium of this species.

Notes on type material: Weidner (1972) listed the holotype and 26 paratypes (various localities, including the type locality) as deposited in ZMUH. I was unable to locate the type material for the species.

Description: Based on macropterous form. Measurements. Length: male 2.51–2.87; female 2.54–2.90; Width: male 1.07–1.15; female 1.12–1.37; Width of head: male 0.89–1.10; female 0.89–1.10; Synthlipsis: male 0.35–0.45; female 0.32–0.46; Width of eye: male 0.25–0.37; female 0.27–0.34; Width of pronotum: male 0.83–1.00; female 0.76–1.00; Length of pronotum: male 0.28–0.36; female 0.29–0.35.

Color: Ground color light to yellowish-brown ( Figs. 57a–b ). Head same color, eyes greyish-silver. Vertex and frons pale brown, clypeus darker. Clypeogenal area same general coloration as head. Labium dark brown. Antennae pale. Pronotum darker brown, with narrow pale band often present along apical margin. Scutellum pruinose medially. Clavus with basal pale, diagonal area, apical portion darker, as in corium and membrane. Corium with dark markings present in interrupted longitudinal series, forming four broken bands. Prenodal embolar area pruinose in basal third. Postnodal embolar area with infuscation appearing as large spots. Left membrane in both sexes hyaline, pale white, and outlined narrowly in apical portion with a dark contiguous band. Venter light brown, legs brown with natatorial setae darkened.

Structural characteristics: Ratio of body length/width: males 2.39; females 2.23. Head wider than pronotum, interocular space greater than width of eye, synthlipsis 1.3 times as wide as posterior width of eye. Ocular index: males 1.34; females 1.41. General facies of head (vertex, frons, labium) proportionate. Antennae densely pilose, segments one and two very short, segment three longer, sub-parallel sided, with upper angle nearly straight and lower angle rounded apically. Pronotum convex, widest at middle with lateral margins tapered, nearly four times as wide as long (W/L males 1.13/0.31; females 1.22/0.32). Prothoracic lobe shorter, anterior margin quadrate, posterior margin narrowly rounded ( Fig. 58a ). Hemelytra with fine transverse microsculpturing. Short setae evenly distributed over clavus, corium, and right membrane. Nodal furrow well-developed, marked by nearly perpendicular suture not reaching outer margin of wing. Prenodal embolar area broad, long, infuscated laterally. Postnodal embolar area broad, about one-third the length of prenodal area. Metathoracic wings well-developed, reaching nearly to apices of hemelytra. Lateral spines on abdominal segments IV–VIII: IV: one stout, short spine, one long seta; V: three stout spines of varying lengths; VI: two short, stout spines, two long spines, one thin, long spine; VII: two stout spines: one short, one long, one thin long spine; VIII: four stout, short spines, one thin, long spine. Metaxyphus of both sexes broadly rounded, setose at apical margin ( Fig. 58b ). Mesotarsal claws long, nearly equal to length of mesotarsus.

L= length, LP= length of pronotum, W= body width, WH= width of head, S= synthlipsis, WE= width of an eye, WP= width of pronotum, L:W= ratio body length to width, S:E= ratio of synthlipsis to eye width, OcI= ocular index.

Male foreleg ( Fig. 58c ): femur with two short, stout spines in basal third near ventral surface and two spines placed medially on dorsal surface. Tibia with one large spine laterally, in anterior portion, and two short spines dorso-apically. Pala with one small seta dorsally; palmar area with about eight setae in dorsal row and 10–11 setae in lower row, lower row setae more pronounced than those of dorsal row. Apex of pala with single thickened seta. Palar claw ( Fig. 59a ) tapered proximad, widening and evenly rounded distally. Female foreleg with same general setal arrangement as male.

Lateral lobes of abdominal tergum IV broadly rounded, each lobe with 12 long, more or less evenly spaced setae. Prestrigilar flap of tergal segment V compact, parallel-sided ( Fig. 58d ). Strigil variable: elongate and, narrowed or rounded, appearing as a small sub-circular disk. Median lobe of sternite VII ( Fig. 58e ) long, with apical portion elongated and rounded distally, setae of uniform length, distributed over medio-basal portion of lobe. Free lobe of tergite VIII ( Figs. 58f , 59b ) narrowed, with outer angle broadly rounded. Setae confined to inner angle and apex, numbering 15–18. Pars stridens processus cleaner ridges of tergite VIII appearing as a fine ridged mat. Left paramere ( Figs. 59c–f ) shorter, shaft rotated laterally and narrowed, tip with sharp apical hook ( Figs. 59c–d ). Base broad. Right paramere ( Figs. 59c–h ) with long, narrowed shaft running entire length, apex curved. Base subquadrate ( Fig. 59h ) with about 48 plectral ribs spanning width. Aedeagus narrowed, as in Figures 59e–g .

Distribution and Habitat: ( Fig. 60 ). A widespread species, known from Iran to Oceania. The New Guinea distribution was recently reviewed and discussed by Tinerella (2006b). In Australia, the species is widespread throughout the east from Queensland to South Australia. The species is newly recorded here from Northern Territory. No specimens were recorded from New South Wales or South Australia during this research. A series of comprehensive studies on the biology and life history of M. quadristrigata Breddin was published by Fernando (1958, 1959, 1960, 1961a, 1961b, 1963a, 1963b, 1963c, and 1964) and Fernando and Leong (1963)

Discussion: Variation seen in the species was discussed by Tinerella (2006b, 2008). The species is superficially similar to M. queenslandica and is readily distinguished by the unique male parameres ( Figs. 59c–h ) and combination of prothoracic lobe ( Fig. 58a ) and metaxyphus ( Fig. 58b ).

Specimens examined: AUSTRALIA: Northern Territory: 97 km N of Barrow Creek. 7-IV-1966. UV Light. N. McFarland. (2♀♀). [ SAMA] ; Northern Territory: 2.8 mi S of Renner Springs. 8-IV-1966. UV Light. N. McFarland. (1♀). [ SAMA] ; Northern Territory: 4 mi W Timber Creek. 14-IV-1966. UV Light. N. McFarland. (4♂, 4♀♀). [ SAMA] ; Northern Territory: Warlock Ponds , 35 mi N of Larrimah. 21-V-1972. B. K. Head. (1♀). [ SAMA] ; Queensland: Normanton. 3-V-1963. Light. N. B. Tindale & P. Aitken. (17♂, 23♀♀). [ SAMA]; same data. 4-V-1963. Light. P. Aitken & N. B. Tindale. (32♂, 45♀♀). [ SAMA]; same data. 5-V-1963. (22♂, 25♀♀). [ SAMA]; same data. 6-V-1963. (1♀). [ SAMA] ; Queensland: Moorington Island, Mission. 12-V-1963. Light. P. Aitken & N. B. Tindale. (7♂, 30♀♀). [ SAMA] .

Figures

FIGURE 57. Micronecta quadristrigata Breddin. a. Male. b. Female. Scale bars = 0.5 mm. (modified from Tinerella, 2008)

FIGURE 58. Micronecta quadristrigata Breddin a. Prothoracic lobe, female. b. Metaxyphus. c. Left male foreleg, posterior aspect. d. Prestrigilar flap of abdominal segment V. e. Sternal process of abdominal segment VII. f. Free lobe of abdominal tergite VIII. Scale bars = 0.1 mm. (modified from Tinerella, 2008)

FIGURE 59. Micronecta quadristrigata Breddin. a. Male fore leg, anterior aspect, palar claw folded in. b. Free lobe of abdominal tergite VIII. c. Left paramere, dorso-lateral aspect. d. Left paramere, tip. e. Right paramere, dorso-lateral aspect. f. Right paramere, latero-medial aspect. g. Right paramere, lateral aspect. h. Pars stridens processus, base of right paramere. (modified from Tinerella, 2008)

FIGURE 60. Australian distribution of Micronecta quadristrigata Breddin.