Micronecta jenniferae Tinerella, 2006

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 : 34-39

Micronecta jenniferae Tinerella, 2006

( Figs. 16c–d , 20–22 )

Micronecta jenniferae Tinerella, 2006a: 697 .

Diagnosis: A small, ovate species recognized by the limited hemelytral markings ( Figs. 16c–d , 20c ), apical scales of the left male paramere ( Figs. 22c–g ), and combination of the prothoracic lobe ( Fig. 21a ) and metaxyphus ( Fig. 21b ) for females. Presently known only from Fiji.

Size: ( Table 8). Brachypterous form: 2.26–2.48. Macropterous form unknown. 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.

Derivation of specific epithet: The species was named honoring Jennifer L. Tinerella.

Notes on type material: Holotype (♂): ( Fig. 20a–c ) FIJI: VITI LEVU: Vatuthere , near Nandarivatu, 2200 feet. IX-8-1938. Stream. Coll. E. C. Zimmerman. [ BPBM]; Type No. 16,620 . Paratypes: FIJI: VITI LEVU: Vatuthere , near Nandarivatu, 2200 feet. IX-8-1938. Stream. Coll. E. C. Zimmerman. (3♂♂, 4♀♀) . [ BPBM]; same data: (1♂, 1♀) . [PPTC].

Description: Based on brachypterous form. Measurements. Length: males 2.26–2.47; females: 2.40–2.48; Width: males 1.23–1.30, females 1.30–1.34; Width of head: males 0.89–0.93; females 0.92–0.94; Synthlipsis: males 0.33–0.39; females: 0.38–0.39; Width of eye: males 0.30–0.32; females: 0.28–0.31; Width of pronotum: males 0.84–0.86; females: 0.86–0.90; Length of pronotum: males 0.18–0.25; females: 0.22–0.23.

Color. Ground color light reddish-brown ( Figs. 16c–d ). Head darker reddish brown, vertex with widened whitish circular area, frontoclypeal area darker, genae punctulate, dark brown to black, eyes black. Labium dark brown to black. Antennae yellowish-brown. Pronotum brown with narrow apical pale band spanning width. Scutellum light brown. Clavus with basal diagonal pale area, reddish area medially, lateroapical portion lighter, brownish-yellow. Corium with basal darker broad area extending laterally to embolium, apical portion yellowish brown. Membrane dark brown apically, apicomedial portion of left membrane hyaline, right membrane similar to corium, setae absent from apical portion. Hemelytra evenly clothed with short, stout setae. Abdomen infuscated, darker; legs brown, metatarsal natatorial setae black.

Structural characteristics. Ratio of body length/width = 1.8 (males and females). Head slightly wider than pronotum, synthlipsis 1.2 times as wide as posterior width of eye. Ocular index: 1.3 (males and females). General facies of head (frons and labium) proportionate. Third antennal segment long, inflated, densely pubescent, antennal segments one and two very short. Pronotum short, nearly six times as wide as long (W/L: males 1.30/0.23, females 1.32/0.23), densely rugose, narrowing laterally, basal portion with median transverse carina. Prothoracic lobe ( Fig. 21a ) rectangular, with scattered setae, distal angle rounded, lower margin broadly rounded. Hemelytral microsculpturing consisting of very fine, dense meshes, short setae evenly distributed throughout hemelytra. Nodal furrow present, bisecting embolar groove. Prenodal embolar area well developed, and wide. Postnodal embolar area very short and tapered apically. Metathoracic wings short, nar- row, reaching apex of abdominal segment VI. Lateral spines and setae on abdominal segments IV–VIII; IV: one short stout spine, two long narrow spines; V: two short stout spines, one stout long spine, one long hairlike spine; VI: two short stout spines, one stout long spine; VII: two short spines, three long; VIII: two short stout spines, two long stout spines. Metaxyphus short, triangular, apex rounded ( Fig. 21b ).

Male foreleg ( Fig. 21c ): Femur with two spines on basal third towards ventral surface. Pala with 13–15 setae in lower palmar row, lower row more pronounced than upper row. Palar claw as in Figure 21d . Female foreleg with same general setal arrangement as male. Mesotarsal claws little less than one-half the length of mesotarsus.

Lateral lobes of abdominal tergum IV asymmetric, lobes broadly rounded. Right lobe longer than left, each lobe with one row of six to eight setae along margin. Prestrigilar flap of abdominal tergite V as in Figure 21e . Strigil very long, narrow, and rectangular with numerous densely packed combs. Median lobe of abdominal sternum VII ( Fig. 21f ) long, rounded apically, glabrous, with setae restricted to basal portion. Free lobe of abdominal tergite VIII ( Fig. 22a ) long, parallel-sided, outer side rounded and inner lobe pronounced apically. Free lobe densely pubescent, with short setae except in medioapical portion, about 15 long setae originating from apical lobe and 10–12 shorter setae in upper right angle. Pars stridens processus cleaner ridges of abdominal segment VIII appearing as a fine-ridged mat ( Fig. 22b ). Left paramere ( Figs. 22c–g ) about 4/5 length of right paramere, shaft nearly parallel-sided, apex curved outward. Apical third of left paramere with large spinelike scales, tip with semi-circular notch. Right paramere ( Figs. 22c–g ) long, broadened apically, shaft constricted towards base. Base of right paramere ( Figs. 22f–h ) subquadrate, with about 36 ridges on pars stridens processus; ridges on lower, rounded portion of pars stridens processus spaced wider, those in upper flat portion packed closely. Aedeagus as in Figures 22e–g .

Distribution and habitat: Known only from the type locality, Vatuthere, Viti Levu, Fiji. A stream inhabitant, according to label data.

Discussion: Micronecta jenniferae was the first micronectid recorded east of the Solomon Islands ( Tinerella 2006a). Previous to this, Micronecta virgata Hale and M. carbonaria Horváth marked the easternmost distribution of the subfamily ( Tinerella and Polhemus 2005). Micronecta jenniferae is closely allied to M. virgata Hale and M. carbonaria Horváth. The distributions and larger sizes of M. virgata (2.94–3.36 mm) and M. carbonaria , (2.96–3.44 mm), as well as the hemelytral patterning and structure, distinguish these species from M. jenniferae . The ground color of M. virgata is brown to dark brown, with hemelytral patterning consisting of four dark longitudinal lines; the ground color of M. carbonaria is typically black with hemelytral patterning absent.

Micronecta jenniferae represents the northeastern distributional limit of the typical ‘Australian’ clade ( Tinerella 2006a, 2006b), which includes M. virgata (northern Australia, Papua New Guinea, Solomon Islands), M. carbonaria ( Solomon Islands), M. annae group ( Australia), M. halei L. C. Chen ( Australia) , M. gracilis Hale ( Australia) , M. major Chen ( Australia) , and M. robusta Hale ( Australia) This clade is united by the presence of the weak transverse basal carina of pronotum, rounded distal angle of free lobe of abdominal tergite VIII, apical scales of left paramere, and rectangular base, pars stridens processus, and apically expanded portion of right paramere.

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 20. Micronecta jenniferae Tinerella, locality labels, holotype, and dorsal habitus. a. Locality labels. b. Type label. c. Holotype specimen, male, dorsal habitus.

FIGURE 21. Micronecta jenniferae Tinerella. 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. Scale bars = 0.1 mm. (Modified from Tinerella 2006)

FIGURE 22. Micronecta jenniferae Tinerella, male abdominal terminalia. a. Free lobe of abdominal tergite VIII. b. Pars stridens processus cleaner ridges of abdominal segment VIII. c. Left paramere, lateral aspect. d. Left paramere, ventrolateral aspect. e. Left paramere, ventrolateral aspect, right paramere, dorsal aspect. f. Left paramere, ventral aspect, right paramere dorsolateral aspect. g. Right paramere, lateral aspect. h. Pars stridens processus, base of right paramere.