Micronecta lansburyi Wróblewski, 1972

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 : 42-48

Micronecta lansburyi Wróblewski, 1972

( Figs. 23–26 )

Micronecta lansburyi Wróblewski, 1972b: 521

Micronecta lansburyi: Wróblewski, 1977: 688 . [faunistics]

Micronecta lansburyi: Andersen and Weir, 2004: 250 . [key; faunistics]

Diagnosis: Recognized at once by the extremely short pronotum, general dorsal habitus ( Figs. 23a–d ), and heavily spined hind tibia.

Size: ( Table 9). Macropterous form: 2.82–3.28. Brachypterous form unknown.

Derivation of specific epithet: Named by Wróblewski (1972b) honoring Ivor Lansbury of the Hope Entomological Collection [OXUM].

Notes on type material: Wróblewski (1972b) reported depositing the holotype (♂) and allotype in ZMPA, and paratypes (1♂, 2♀♀) in OXUM. I was unable to obtain any type material for examination.

Description: Based on macropterous form. Measurements. Length: male 2.82–3.01; female 3.02–3.28; Width: male 1.41–1.58; female 1.59–1.74; Width of head: male 1.14–1.22; female 1.24–1.29; Synthlipsis: male 0.55–0.58; female 0.57–0.60; Width of eye: male 0.31–0.34; female 0.31–0.37; Width of pronotum: male 1.00–1.14; female 1.16–1.22; Length of pronotum: male 0.21–0.26; female 0.22–0.28.

Color: Ground color dark brown ( Figs. 23c–d ). Head same color, eyes black. Vertex with slight restricted infuscation. Frons, clypeus, and genae unicolorous dark brown. Labium dark brown. Antennae pale brown. Pronotum dark brown, unicolorous, some specimens possessing narrow, pale apical band spanning pronotal width. Scutellum dark brown. Clavi each with basal broad, pale diagonal area well-developed although width of the pale band varies. Medial and apical portions of clavi same ground color as rest of hemelytra. Corium unicolorous light brown, with dark markings absent or developed as a series of four narrow longitudinal lines (see discussion below). Prenodal embolar area long and narrow, unicolorous brown, post-nodal embolar area very short and same color as rest of embolar groove. Left membrane of both sexes sub-hyaline, pale at innermost margin. Venter of both brown, lateral portions infuscated. Legs darker brown with natatorial setae same color.

Structural characteristics: Ratio of body length/width: males 1.96; females 1.87. Head width slightly wider than pronotal width, synthlipsis 1.7 times as wide as posterior width of eye. Ocular index: males 1.87; females 1.71. General facies of head (vertex, frons, and labium) proportionate, though head length is shorter than that of typical Micronecta species. Third antennal segment densely pilose, shorter, apex angulate; segments one and two very short. Pronotum very short, basal and apical margins nearly parallel-sided; flattened to somewhat convex, lateral margins weakly tapered and squared, averaging five times as wide as long (W/L: males 1.05/0.23; females 1.20/0.24). Prothoracic lobe short, relatively broad, with lower margin nearly straight and posterior margin rounded ( Fig. 24a ). Hemelytral microsculpturing consisting of small, dense circular meshes distributed over entire surface. Short setae uniformly distributed over entire hemelytral surface. Metathoracic wings well-developed, reaching to apex of hemelytra. Lateral spines on abdominal segments IV–VIII: IV: one stout, short spine, two thin, long setae; V: one stout, short seta, two long, stout setae, one long, thin seta; VI: one stout, short seta, two long, stout setae; VII: three short, stout spines, one long, stout spine; VIII: seven stout setae of varying lengths, two long, thin setae. Metaxyphus of both sexes broadly triangular, apex acuminate ( Fig. 24b ).

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. 24c ): femur with two short, stout spines in basal third near ventral surface and two smaller spines nearer base. Tibia with one short spine in apico-ventral portion and three short setae, one dorso-medially and two apically. Pala with four longer setae and one spine-like seta dorsally; 11 setae in upper palar row and 14–16 setae in lower palar row, lower row setae more pronounced than those of dorsal row. Apex of pala with a longer thickened seta. Palar claw ( Fig. 24d ) parallel-sided with apical notch. Female foreleg with same general setal arrangement as male. Mesotibiae armed with numerous stout spines along length. Mesotarsal claws long, equaling nearly two-thirds the length of the mesotarsus.

Lateral lobes of abdominal tergum IV broad, asymmetric, and rounded apically. Right lobe longer, with six long setae, left lobe with seven long evenly spaced, apically placed setae. Prestrigilar flap of tergal segment V as in Figure 24e . Strigil well-developed, very long and broader, with few combs. Median lobe of sternite VII ( Fig. 24f ) broad basally, with numerous scattered setae and interspersed darker areas, apex narrowed and shorter. Free lobe of tergite VIII ( Fig. 24g ) broad, triangular in outline, outer angle rounded and inner angle comparatively long. Setae of varying lengths placed over entire apical portion and numbering about 28. Pars stridens processus cleaner ridges of tergite VIII not examined. Male left paramere ( Figs. 25a–f ) relatively short, shaft broad and parallel-sided in lateral view, apex acutely curved, with blunt rounded process, apical scales prominent in inner portion before apex. Base broad, upper portion reaching about one-third the length from base, lower portion of base short, rounded ( Figs. 25a–f ). Right paramere ( Figs. 25a–h ) very long and narrow, parallel-sided and sharply curved, apical portion curved outward, slightly expanded, with tip acuminate ( Figs. 25c, e, g ). Base short and broad, quadrate in outline. Pars stridens processus consisting of about 40 plectral ribs spanning lower and rear portion of paramere base ( Fig. 25h ). Aedeagus broad, as in Figures 25a–f .

Distribution and Habitat: ( Fig. 26 ). AUSTRALIA: Northern Territory, Queensland, Western Australia. Widespread throughout northern Australia. Little habitat data are available for the species. Some specimens examined from this research were taken at lights.

Discussion: In addition to the unique male parameres, Micronecta lansburyi possesses heavily-spined hind tibia, unique to the taxon. Further, the extremely short pronotum serves to distinguish the species. All examined specimens were macropterous, indicating the short pronotal length seen is not directly proportionate to brachypterous form.

In Wróblewski’s description (1972b), he noted specimens having produced hemelytral markings similar to M. virgata . All specimens examined in this research had unicolorous dark brown hemelytra, except for a series of specimens from Fraser Island, Queensland (1♂, 5♀♀; ANIC), which had weakly to well-produced longitudinal hemelytral markings. All other characters discussed by Wróblewski are similar to specimens examined here. The slightly notched palar claw of M. lansburyi is unique among Australasian Micronecta .

On the basis of the male parameres and tergal morphology, M. lansburyi is closely allied with the annae species group. As with other species of the annae group, the apical scales of the left male paramere are welldeveloped.

Specimens examined: AUSTRALIA: Northern Territory: near Darwin. 28-V-1918. G. F. Hill. (1♀). [ SAMA] ; Northern Territory: Warlock Ponds , 35 mi N of Larrimah. 21-VI-1972. B. K. Head. (1♀). [ SAMA] ; Northern Territory: S Alligator River area , 35 km W Jabiru. 9-IV-1980. Black Light. G. F. Hevel & J. A. Fortin. (3♂, 8♀♀). [ USNM] ; Queensland: N Hann River , 110 km S of Coen. 27-VI-1970. J. C. LeSouef. (2♂, 2♀♀). [ MVMA] ; Queensland: Fraser Island, Boomerang South. 9-I-1972. (1♂, 5♀♀). [ ANIC] ; Western Australia: 4 km S by W of Mining Camp, Mitchell Plateau, Kimberley Dist. , Stop 17. 14.52S; 125.50E. 13-V-1983. D. G. F. Rentz & J. Balderson. (13♂, 11♀♀). [ ANIC] .

Figures

FIGURE 23. Micronecta lansburyi Wróblewski, dorsal habitus. a. Male, ethanol preserved specimen. b. Female, ethanol preserved specimen. c. Male, dried specimen. d. Female, dried specimen. Scale bars = 0.5 mm.

FIGURE 24. Micronecta lansburyi 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 25. Micronecta lansburyi Wróblewski, male genitalia. a. Left paramere, lateral aspect, right paramere, dorsal aspect. b. Left paramere, medio-lateral aspect, right paramere, dorso-medial aspect. c. Left paramere, ventro-lateral aspect (cf base Fig. a,b,e), right paramere, dorsal aspect. d. Left paramere, tip. e. Left paramere, fronto-medial aspect, right paramere, lateral aspect. f. Left paramere, ventro-medial aspect, right paramere, medio-lateral aspect. g. Right paramere, tip. h. Pars stridens processus, base of right paramere.

FIGURE 26. Distribution of Micronecta lansburyi Wróblewski.