Micronecta halei Chen, 1965

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 : 97-101

Micronecta halei Chen, 1965

( Figs. 53–56 )

Micronecta halei Chen, 1965: 157 .

Micronecta windi Chen, 1965: 161 .

Micronecta halei: Wróblewski 1970: 695 . (junior synonym, secondary junior homonym)

Micronecta halei: Wróblewski, 1972b: 518 . [note]

Micronecta windi: Wróblewski, 1972b: 518 . [suspected synonymy]

Micronecta halei: Cassis and Gross, 1995: 68 . [catalogue]

Micronecta windi: Cassis and Gross, 1995: 70 . [catalogue]

Micronecta halei?: Halse et al., 2000: 260 . [list]

Micronecta halei: Andersen and Weir, 2004: 250 , 334. [key; list]

Diagnosis: Recognized by combination of the following characters. Faintly developed hemelytral patterning ( Figs. 53b–d ), metaxyphus ( Fig. 54b ), distally expanded male palar claw ( Fig. 54d ), sternal process of abdominal segment VII ( Fig. 54f ), and the distinct male genitalia ( Figs. 55a–e ). Similar in general habitus to Micronecta quadristrigata and M. queenslandica .

Size: ( Table 17). Macropterous form: 2.77–3.34 mm. Brachypterous form unknown.

Derivation of specific epithet: Chen (1965) named the species honoring Dr. H. M. Hale.

Notes on type material: Holotype, allotype, and 11 paratypes are deposited in SAMA. In addition, two males and eight females paratypes are deposited in SEMC. I have examined the holotype ( Figs. 53a–b ), allotype, and nine paratypes from SAMA, and five paratypes from SEMC.

Description: Based on macropterous form. Measurements. Length: male 2.77–3.11; female 3.18–3.34; Width: male 1.36–1.46; female 1.42–1.51; Width of head: male 1.02–1.23; female 1.15–1.23; Synthlipsis: male 0.43–0.50; female 0.33–0.53; Width of eye: male 0.31–0.42; female 0.33–0.43; Width of pronotum: male 1.01–1.19; female 1.13–1.19; Length of pronotum: male 0.33–0.52; female 0.48–0.59.

Color: Ground color dark brown ( Figs. 53b–d ). Head dark brown, eyes silvery-brown. Vertex infuscated, frons, clypeus, and genae unicolorous dark brown with darker areas throughout. Labium black. Antennae pale brown. Pronotum dark brown, unicolorous, with expanded pale apical band spanning width. Scutellum dark brown, pruinose medio-apically. Clavi each with basal broad, pale diagonal area well-developed, medial and apical portions same ground color as rest of hemelytra. Lateral margins of clavi outlined with narrow, pale line. Corium dark brown, lateral margins with lighter areas. Hemelytral patterning not well-developed, at most, a faint linear pattern discernible in medial portion of corium. Prenodal embolar area long and narrow, infuscated medially, postnodal embolar area well-developed, short and broad. Left membrane of both sexes subhyaline. Venter of both sexes light brown. Natatorial setae of metatarsus not especially darkened.

Structural characteristics: Ratio of body length/width: males 2.12; females 2.22. Width of head generally greater than pronotal width, synthlipsis 1.2 times as wide as posterior width of eye. Ocular index: males 1.46; females 1.18. General facies of head (vertex, frons, and labium) proportionate. Third antennal segment densely pilose, ovate, apex narrowly rounded, segments one and two very short. Pronotum robust, convex, widest at middle with lateral margins tapered and truncate, about 2.5 times as wide as long (W/L: males 1.11/0.43; females 1.17/ 0.52). Prothoracic lobe short, relatively narrow with anterior and lower margins squared, posterior margin rounded ( Fig. 54a ). Hemelytral microsculpturing consisting of dense, transverse meshes distributed over entire surface. Short setae uniformly distributed over entire hemelytral surface, setae sparse in basal portion of clavus. Metathoracic wings well-developed, reaching nearly to apex 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; VI: two stout, short setae, two long, stout setae; VII: one short, stout spine, one long, thin spine, two long, thin setae; VIII: eight stout, short spines, two long, thin setae. Metaxyphus of both sexes narrow, short and triangular, with apex rounded ( Fig. 54b ).

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. 54c ): femur with two short, stout spines in basal third near ventral surface and two prominent setae near base. Tibia with one long, stout spine in medial portion. Pala with five setae dorsally; 13 setae in upper palar row and 15–16 setae in lower palar row, lower row setae more pronounced than those of dorsal row. Apex of pala with a shorter thickened seta. Palar claw ( Fig. 54d ) tapered proximad and broad apically. Female foreleg with same general setal arrangement as male. Mesotarsal claws equaling about one-third the length of the mesotarsus.

Lateral lobes of abdominal tergum IV broad, asymmetric. Right lobe longer, truncate apically, with 13 long setae, left lobe rounded apically, with 15 long evenly spaced, apical setae. Prestrigilar flap of tergal segment V as in Figure 54e . Strigil small, nearly circular in outline, with few combs. Median lobe of sternite VII ( Fig. 54f ) very broad basally, with numerous scattered setae, apex constricted, short and acuminate. Free lobe of tergite VIII ( Fig. 54g ) broad, nearly quadrate with outer angle rounded and long inner angle. Setae of varying lengths confined to inner angle and apex, numbering about 26. Pars stridens processus cleaner ridges of tergite VIII not examined. Male left paramere ( Figs. 55a–d ) long, parallel-sided, apex tapering with semi-circular hook-like distal process, apical scales present along inner portion and within hooked area. Base broad, upper portion reaching about onethird the length of the shaft, lower portion of base longer and rounded ( Figs. 55a–c ). Right paramere ( Figs. 55a, c–d ) long and relatively broad, shaft curved with tip gradually tapering to a blunt point ( Fig. 55d ). Base long and wide, quadrate in outline. Pars stridens processus consisting of about 34 plectral ribs spanning lower portion of paramere base ( Fig. 55e ). Aedeagus broad, as in Figures 55a–d .

Distribution and Habitat: ( Fig. 56 ). AUSTRALIA: Queensland, South Australia, Western Australia. Previously unrecorded for South Australia. No collection method or habitat data accompany the examined specimens.

Discussion: As Chen (1965) stated, the general appearance of Micronecta halei lacks any diagnostic features. General habitus suggests M. quadristrigata or M. queenslandica , however, all specimens examined possessed the light pronotal spots seen in Figures 53b–d , which are seemingly unique to the species. The expanded apex of the palar claw discussed by Chen (1965) is indeed as such, however, cannot be relied on solely to distinguish males. Male genitalia of M. halei are diagnostic, as seen from the broad base and angled apex of the left paramere ( Figs. 55a–d ). The right paramere is similar in form to M. annae ( Figs. 55a, c–d ).

The identity of M. windi Chen is presently unclear. Chen (1965: 161) noted the similarity of M. halei and M. windi with her discussion based on the general habitus and the sternal process of abdominal segment VII. She also cited differences seen in the male genitalia for separation of the two. Micronecta windi was described from two males from Kuranda, Queensland.

Wróblewski (1972b) stated the suspected synonymy of M. halei and M. windi based on his genitalic examination of additional male specimens of M. halei , but refrained from formal synonymy apparently because he had not seen Chen’s two male specimens. I was able to examine Chen’s paratype of M. windi at SEMC, but was unable to dissect the specimen for genitalic examination and therefore could not positively confirm the identity. In the course of this research, I have not examined any specimens identifiable as M. windi . Re-examination of the two male specimens of M. windi [SEMC], along with additional specimens of M. halei is needed to resolve this issue.

Specimens examined: AUSTRALIA: South Australia: Cannuwaukaminna Bore , 11 km SW Etadunna H. S. 29-VII-1984. Bore Drain. D. Lacis. (1♂). [ SAMA] ; Western Australia: Woodstock Station , WS 9. 21 37S; 119 01 24E. 24-IX-1988. UV Light. B. P. Hanich. (16♂, 26♀♀). [ WAMP] .

Figures

FIGURE 53. Micronecta halei Chen, holotype and dorsal habitus. a. Locality and type labels. b. Holotype specimen, male, dorsal habitus. c. Male. d. Female. Scale bars = 0.5 mm.

FIGURE 54. Micronecta halei 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 tergum VIII. Scale bars = 0.1 mm.

FIGURE 55. Micronecta halei Chen, male genitalia. a. Left paramere, lateral aspect, right paramere, dorsal aspect. b. Left paramere, tip. c. Left paramere, ventro-lateral aspect, right paramere, dorso-lateral aspect. d. Right paramere, lateral aspect, left paramere, tip. e. Pars stridens processus, base of right paramere.

FIGURE 56. Distribution of Micronecta halei Chen.