Micronecta quadristrigata Breddin, 1905

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 : 39-45

publication ID	https://doi.org/ 10.11646/zootaxa.1797.1.1
persistent identifier	https://treatment.plazi.org/id/127787F4-FF80-415C-FF61-F39BFC175D8F
treatment provided by	Felipe
scientific name	Micronecta quadristrigata Breddin, 1905
status

Treatment

( Figs. 16e–f View FIGURE 16 , 23–25 View FIGURE 23 View FIGURE 24 View FIGURE 25 )

? Sigara lineata Fieber, 1844: 15 View in CoL . (junior secondary homonym of Notonecta lineata Forster, 1771 ; primary junior hom-

onym of Sigara lineata Fabricius, 1787 View in CoL ; junior secondary homonym of Corixa lineata Rambur, 1840 ) (suspected

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]

Diagnosis: This widespread, highly variable species is readily identified by the widened interocular space ( Figs. 16e–f View FIGURE 16 ), distinctive free lobe of abdominal tergite VIII ( Figs. 23f View FIGURE 23 , 24b View FIGURE 24 ), and the male parameres ( Figs. 24c–h View FIGURE 24 ). Females are readily associated with males based on size and general hemelytral appearance and combination of the prothoracic lobe ( Fig. 23a View FIGURE 23 ) and metaxyphus ( Fig. 23b View FIGURE 23 ).

Size: ( Table 9). Macropterous form: 2.51–2.90. Wróblewski (1970) reported females up to 3.22 mm.

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: From the Latin combination quadri-, meaning four, and - strigata, meaning streak. The name most probably refers 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. Type material not located for examination .

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. 16e–f View FIGURE 16 ). Head same color, eyes grayish-silver. Vertex and frons pale brown, clypeus darker. Clypeogenal area same general coloration as head. Labium dark brown. Antennae pale. Pronotum darker brown, often with narrow pale band 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. Right membrane coriaceous, brown. Venter light brown, legs brown, 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) evenly proportionate. Antennae densely pilose, segments one and two very short, segment three longer, subparallel-sided, upper angle nearly straight and lower angle rounded apically. Pronotum convex, widest at middle, 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. 23a View FIGURE 23 ). Hemelytra with fine transverse microsculpturing. Short setae evenly distributed over clavus, corium, right membrane. Nodal furrow well developed, marked by nearly perpendicular suture not reaching outer margin of wing. Pre-nodal embolar area broad, long, infuscated laterally. Post-nodal embolar area broad, about one-third length of pre-nodal area. Metathoracic wings well developed, reaching nearly to apices of hemelytra. Lateral spines and setae on abdominal segments IV–VIII: IV: one stout, short spine, one long; V: three stout spines of varying lengths; VI: two short, stout spines, two long, and 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. 23b View FIGURE 23 ). Mesotarsal claws long, nearly equal to length of mesotarsus.

Male foreleg ( Fig. 23c View FIGURE 23 ): 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 dorsoapically. 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. 24a View FIGURE 24 ) 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 abdominal tergum V compact, parallel-sided ( Fig. 23d View FIGURE 23 ). Strigil variable: elongate and narrowed, or rounded, appearing as a small subcircular disk. Median lobe of abdominal sternum VII ( Fig. 23e View FIGURE 23 ) long, with apical portion elongated and rounded distally; setae of uniform length, distributed over mediobasal portion of lobe. Free lobe of abdominal tergite VIII ( Figs. 23f View FIGURE 23 , 24b View FIGURE 24 ) narrowed, with outer angle broadly rounded. Setae confined to inner angle and apex, numbering 15–18. Pars stridens processus cleaner ridges of abdominal segment VIII appearing as a fine-ridged mat. Left paramere ( Figs. 24c–f View FIGURE 24 ) shorter, shaft rotated laterally and narrowed, tip with sharp apical hook ( Figs. 24c–d View FIGURE 24 ). Paramere base broad. Right paramere ( Figs. 24c–g View FIGURE 24 ) with long, narrowed shaft running entire length, apex curved. Base of right paramere subquadrate ( Fig. 24h View FIGURE 24 ), with about 48 plectral ribs spanning width. Aedeagus narrowed, as in Figures 24e–g View FIGURE 24 .

Distribution and habitat: ( Fig. 25 View FIGURE 25 ). [widespread: Iran to Oceania]. Recorded here from: Molucca Islands, Australia, New Guinea, Solomon Islands. This species is very abundant throughout the Paleotropical region and is often the dominant taxon in light trap samples. The species is less common in Australia, judging from its low abundance in numerous light trap collections and among museum collections. Nieser and Chen (1999) noted the species’ affinity for “strongly disturbed areas.” Comprehensive studies on the abundance, distribution, habitats, and life history of Micronecta quadristrigata Breddin were published by Fernando (1958, 1959, 1960, 1961a, 1961b, 1963a, 1963b, 1963c, and 1964) and Fernando and Leong (1963).

Discussion: The widespread distribution, high abundance, and great variation of this generalist species has lead to much confusion and synonymy. Kirkaldy (1897b: 240) proposed the replacement name Sigara mnotata for S. lineata Fieber 1844 = Micronecta lineata ( Fieber, 1844) . Fieber’s name was preoccupied by Notonecta lineata Forster 1771 = Sigara lineata ( Forster, 1771) . Wróblewski (1968: 776) listed M. m-notata Kirkaldy as a synonym of M. scutellaris and at the same time apparently suspected M. lineata (Fieber) to be a synonym of M. quadristrigata Breddin. Because M. m-notata is a replacement name for M. lineata , the synonymy is not possible. Based on name priority, Kirkaldy’s M. m-notata should be the species name for the concept of M. quadristrigata ; however, since the name has never been applied since Kirkaldy’s replacement (1897b), M. m-notata is designated here as nomen oblitum (ICZN 1999; article 23.9.2). Micronecta quadris- trigata Breddin is retained [nomen protectum] for nomenclatural stability.

Wróblewski (1968) synonymized Micronecta minthe Distant, 1910: 347 with M. quadristrigata , at the time apparently unaware that Lundblad (1933: 87) had previously synonymized M. minthe . Later, Wróblewski, (1972a: 33) acknowledged Lundblad’s (1933) synonymy and, based on his own re-examination of Distant’s specimens of M. minthe (4♂♂, 3♀♀), concluded that, from the original series, two forms were evident: M. quadristrigata (3♂♂) and “form” minthe . (1♂, 3♀♀). From the series of the form minthe, Wróblewski designated a lectotype and stated that in the future the form might be elevated to subspecies. In his catalog, Jansson (1995) stated that form minthe (sensu Wróblewski) must be regarded as a full species, based on its sympatry with M. quadristrigata . The status of M. minthe remains unresolved and further examination of the material is needed to determine if M. minthe is a valid species or a synonym of M. quadristrigata .

The species is common throughout a wide range of artificial and natural habitats ( Fernando 1958 and see above), and is readily taken at lights. Specimens examined across the geographical range show variation in body size, particularly relative proportions of the pronotum and synthlipsis, as well as hemelytral markings. Variation is also seen in the male strigil, with its shape ranging from small and rounded, to elongated and narrowed (see also above in description). I examined both forms of the strigil, as well as intermediates, in this research, among specimens from the Moluccan Islands, Papua New Guinea, and the Solomon Islands. I have also seen variation of the male strigil in other widely distributed taxa, particularly M. annae Kirkaldy ( Australia) and M. scutellaris (Stål) (Palearctic) ; and I regard this as within the natural variability for these species. In such instances, I have relied on the male genitalia for separation of these species, and further used a combination of metrics and other diagnostic characters (prothoracic lobe, metaxyphus, and hemelytral structure and patterning) for association of females.

I have seen little overall variation in the free lobe of abdominal tergite VIII in M. quadristrigata , as well as little variation of the male parameres. Like those of the widespread M. ludibunda , the male parameres of M. quadristrigata presently provide the best means for distinguishing the species. Further study of M. quadristrigata across its range is needed to define the overall variation of the species. Two recently described species serve to illustrate this point: M. altera Wróblewski ( Wróblewski 1972a) (widespread; India to China) and M. kymatista Nieser and Chen ( Nieser and Chen, 1999) (Borneo and Sulawesi). Both species were described on

the basis of minor differences in the above characters, the authors of both species citing differences in habitat. As illustrated and described, the two species appear very similar to M. quadristrigata . Unfortunately, I was unable to obtain specimens of either species for examination.

Specimens Examined: INDONESIA: Irian Jaya Prov. [= Papua Prov.]: Neth. Hollandia, Binnen , 100 m. 22–XI-1958. Light Trap. J. L. Gressitt. (1♀). [ BPBM] ; Irian Jaya Prov. [= Papua Prov.]: Neth. Bodem , 100 m, 11 km SE of Oerberfaren. (7-17)- VII-1959. MV Light Trap. T . C. Maa. (1♀). [ BPBM] ; Irian Jaya Prov. [= Papua Prov.]: Hol Maffen , 22 km E of Sarmi. (18-19)- VII-1959. T . C. Maa. (3♀♀). [ BPBM] ; Irian Jaya Prov. [= Papua Prov.]: Neth. Warris , S of Hollandia, 450– 500 m. (16–23)- VIII-1959. Lights. T . C. Maa. (1♂). [ BPBM] ; Irian Jaya Prov. [= Papua Prov.]: lower Minajerwi River, E of Timika. 23-I-1996. D. A. Polhemus. (3♀♀). [ USNM]; Moluccan Islands: Ternate. 10-VIII-1954. A. H. G. Alston. (2♂♂, 1♀). [ BMNH] ; PAPUA NEW GUINEA: Morobe Dist.: Gusap, Markham, Valley c . 90 m. W. of Lae, 1000ft. (27–30)- I-1965. M. E. Bacchus. (4♂♂, 2♀♀). ( BMNH); New Guinea. 1945. S. G. Jewett. (69♂♂, 85♀♀). ( USNM); NW: W Sentani , 90 m. (24–25)- VI-1959. MV Light Trap. Gressitt and Maa. (1♀). ( BPBM); SE: Oriomo River , 6 m. 12-II- 1964. H. Clissold. (1♀). [ BPBM]; SE: Moorhead , 18 m. 4-VII-1964. Light Trap. H. Clissold. (1♀). ( BPBM); SE: Daragi , 21 m. 6-VIII-1964. Light Trap. H. Clissold. (1♀) ( BPBM) .

ZMUH	Zoological Museum, University of Hanoi
BPBM	Bishop Museum
MV	University of Montana Museum
T	Tavera, Department of Geology and Geophysics
USNM	Smithsonian Institution, National Museum of Natural History

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Taxonomy

Kingdom	Animalia
Phylum	Arthropoda
Class	Insecta
Order	Hemiptera
Family	Corixidae
Genus	Micronecta