Micronecta queenslandica Chen, 1965

Tinerella, Paul P., 2008, Taxonomic revision and systematics of New Guinea and Oceania pygmy water boatmen (Hemiptera: Heteroptera: Corixoidea: Micronectidae), Zootaxa 1797 (1), pp. 1-66 : 45-49

Micronecta queenslandica Chen, 1965

( Figs. 16g –h , 26–28 )

Micronecta queenslandica Chen, 1965: 159

Micronecta annae kirkaldyi Wróblewski, 1970: 688 . [syn. Wróblewski, 1972b: 519]

Micronecta queenslandica: Wróblewski, 1972b: 519 . [note]

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

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

Diagnosis: Superficially similar in size and general habitus to Micronecta quadristrigata ( Figs. 16e–h ). Micronecta queenslandica is readily distinguished by the male parameres ( Figs. 27a–d ) and combination of the prothoracic lobe ( Fig. 26a ), metaxyphus ( Fig. 26b ), and sternal process of abdominal segment VII ( Fig. 26f ).

Size: ( Table 10). Macropterous form: 2.6–3.0 mm. Brachypterous form unknown.

Derivation of specific epithet: Named for the type locality state, Queensland, Australia ( Chen 1965).

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

Notes on type material: Type series deposited in SEMC, along with 2♂♂, in SAMA ( Chen 1965). Type material examined from SEMC. Two female paratypes also examined from ANIC.

Description: Based on macropterous form. Measurements. Length: male 2.67–2.86; females 2.79–2.93; Width: male 1.19–1.28; female 1.24–1.29; Width of head: male 1.00–1.07; female 0.99–1.06; Synthlipsis: male 0.37–0.39; female 0.36–0.40; Width of eye: male 0.35–0.36; female 0.33–0.37; Width of pronotum: male 0.96–1.03; female 0.92–1.03; Length of pronotum: male 0.32–0.35; female 0.31–0.33.

Color. Ground color yellowish-brown ( Figs. 16g –h ). Head pale yellow, eyes silver. Frons slightly darker, vertex, clypeus, genae pale yellow. Labium brown. Antennae pale yellow. Pronotum dark brown, with narrow pale band along apical margin. Scutellum dark brown. Clavus with basal diagonal area generally developed, pale yellow. Medial and apical portion of clavus same color as corium and membrane. Corium brown, with irregular darker markings. Prenodal embolar area with one or two large darker brown spots, pruinosity confined to basal portion. Postnodal embolar area short, one darker spot laterally on apical portion of embolium. Left membrane of both sexes hyaline, pale, right membrane coriaceous, brown. Venter of both sexes pale yellow, slightly suffused with grey. Legs of both sexes pale, natatorial setae of metatarsus darkened.

Structural characteristics. Ratio of body length/width: males 2.25; females 2.26. Head width about equal to pronotal width, interocular space nearly equal to width of eye, synthlipsis 1.1 times as wide as posterior width of eye. Ocular index: males 1.18; females 1.21. General facies of head (vertex frons, labium) proportionate. Antennae densely pilose, segments one and two very short, segment three longer, elongate, upper and lower margins evenly rounded, apex acuminate. Prothoracic lobe broad, anterior angle quadrate, posterior margin truncate ( Fig. 26a ). Pronotum large, convex, widest at middle, lateral margins narrowly tapered, about 3 times as wide as long (W/L males 0.98/0.34; females 1.00/0.32). Hemelytral microsculpturing consisting of indistinct wavy lines. Short setae evenly distributed over clavus, corium, right membrane. Pre-nodal embolar area long, broad, well developed. Nodal furrow well developed, marked by near perpendicular suture not reaching outer wing margin. Post-nodal embolar area very short, widened basally, inconspicuous apically. Metathoracic wings well developed, reaching apices of hemelytra. Lateral spines and setae on abdominal segments IV–VIII: IV: one long, stout spine, two long, thin setae; V: two short, stout setae, two short, thin setae; VI: three short, stout setae, one long, stout spine, one long, thin spine; VII: four stout setae: two short, stout setae, two long, stout setae, one long, thin seta; VIII: five stout setae of varying lengths, five long, thin setae. Metaxyphus of both sexes short, triangular, apex broadly rounded, short setae distributed over entire surface with three to four longer setae in basal portion ( Fig. 26b ).

Male foreleg ( Fig. 26c ): femur with two short, stout spines in basal third near ventral surface and two short setae dorsoapically. Tibia with one large spine in apicoventral portion. Pala with two to three dorsal setae in medial and apical portions, palmar area with about seven setae in dorsal row and 11–12 setae in lower row, lower row setae more pronounced than those of dorsal row. Apex of pala with single short, thickened seta. Palar claw ( Fig. 26d ) narrow, tapered proximad, parallel-sided and with apex rounded. Female foreleg with same general setal arrangement as male. Mesotarsal claws about one-half length of mesotarsus.

Lateral lobes of abdominal tergum IV short, rounded, right lobe slightly longer than left. Right lobe with about four long setae and left lobe with about five long setae, evenly spaced and confined medially. Prestrigilar flap of abdominal tergum V narrow, long, upper angle acutely produced ( Fig. 26e ). Strigil expanded, elliptical in outline. Median lobe of abdominal sternum VII ( Fig. 26f ) long, apex narrowed and blunt, setae restricted to basal portion. Free lobe of abdominal tergite VIII ( Fig. 26g ) lacking inner angle, outer angle well produced, elongate. Apex of lobe with 14–19 very long setae. Pars stridens processus cleaner ridges of abdominal segment VIII appearing as a fine-ridged mat of two series; one of longer ridges and one of shorter ridges. Left paramere ( Figs. 27a–c ) slightly shorter, with broad shaft, tip triangular and pointed with recurved area cut out ventrally. Left paramere base long, evenly rounded. Right paramere ( Figs. 27a–c ) long, parallelsided, distal portion curved downward; tip acuminate. Base of right paramere compact, squared, ( Fig. 27d ), with about 24 plectral ribs spanning lower portion of base. Aedeagus short, broad ( Figs. 27a–c ).

Distribution and habitat: ( Fig. 28 ). Papua New Guinea and northern Australia. The species is newly recorded here for Papua New Guinea. Specimens examined were taken at lights and one in a malaise trap. No further ecological or habitat data are available.

Discussion: The species is previously unrecorded for Papua New Guinea, having been described from Queensland, Australia. The taxon shows similarity with Micronecta quadristrigata , on the basis of habitus and the sigmoid free lobe of abdominal tergite VIII. The male genitalia of the two species are however, very distinct. Some affinity with Australian Micronecta is also noted, based on the presence of the scale-like sculpturing of the male left paramere. The species lacks the anterior pronotal carina of typical Australian species ( annae species group). Further relationship to other Australian taxa is seen in the form of the pala and palar claw and morphology of the relatively shortened sternal lobe of abdominal segment VII.

The restricted presence of M. queenslandica in southeastern New Guinea, its northern Australian distribution, and characters shared with typical Australian Micronecta taxa place the species within the annae species group.

Specimens Examined: PAPUA NEW GUINEA: SE: Moorhead , 18m. 4-VIII-1965. Light Trap. H. Clissold. (1♂, 7♀♀). [ BPBM] ; same data. 6-VIII-1965. Light Trap. H. Clissold. (1♀). [ BPBM] ; NE: Wau, Big Wau Creek , 1300m. XI-1965. Malaise Trap. J. L. Gressitt. (1♀). [ BPBM] ; AUSTRALIA: Northern Territory: Warlock Ponds , 35 mi N of Larrimah. 21-VI-1972. Lights. B. K. Head. (2♂♂, 2♀♀). [ SAMA] ; Northern Territory: 10 mi E of Daly River. 28-VI-1972. Lights. B. K. Head. (2♂♂). [ SAMA] ; Queensland: Townsville. 1920. G. F. Hill. (1♀). [ ANIC] ; same data. (1♀). [ SEMC] ; Queensland: North Queensland. VI-1954. M. Laird (1♀). [ ANIC] ; Queensland: North Queensland. 13-VI-1954. M. Laird. (1♂). [ SEMC] ; same data. 14-VI-1954. (1♂, 1♀). [ SEMC] .

Figures

FIGURE 16. Dorsal habitus of Micronecta species. a–b. M. ludibunda Breddin, male and female. c–d. Micronecta jenniferae Tinerella, male and female. e–f. M. quadristrigata Breddin, male and female. g–h. M. queenslandica Chen, male and female. i–j. M. carbonaria Horvath, male and female. k–l. M. virgata Hale, male and female. Scale bars = 0.5 mm.

FIGURE 26. Micronecta queenslandica 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 tergite VIII. Scale bars = 0.1 mm.

FIGURE 27. Micronecta queenslandica Chen, male genitalia. a. Left paramere, lateral aspect, right paramere, dorsolateral aspect. b. Left paramere, dorsolateral aspect, right paramere, tip. c. Right paramere, lateral aspect. d. Pars stridens processus, base of right paramere.

FIGURE 28. Distribution of Micronecta queenslandica Chen.