Dextritubus Hill, 2015, gen. n.
Creators: name: Hill, Lionel
Publisher: name: Zenodo
Year: 2015
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hemiptera
Schizopteridae
Dextritubus

description: Dextritubus gen. n.
(Figs 2–10, dimensions in Table 1)
Material. Holotype male of Dextritubus cucullatus sp. n. as well as other material of this species and two additional new species listed below.
Diagnosis. Mostly brown, 0.85–1.05mm long, oval in dorsal view, moderately convex in lateral view (Figs 6, 7, 8D, 10A–B) general setae short, one macroseta on anteclypeus, antennae reaching halfway along body, A3 only 100–115% as long as A4, labium 3-segmented reaching mid coxae, head declivent, half as long as high, male frons with medial pore with (Figs 4A–E) or without (Figs 8C–D) salient dorsal hood, eyes medium, overlapping pronotal collar, ocelli absent, distal half of mesoscutellum not salient posterodorsally, fore wings elytrous, not overlapping, venation evident, male tarsal formula 3,3,3, female 2,2,3; male right paramere long, reaching to left posterolateral angle of T7, anophore bearing tubular process that projects anteroventrally to right to level of S6 (Figs 3C, 5C), vesica spinous, less than or equal to length of right paramere, aligned with tubular process (Fig. 5C); female with posterolateral angles of T8 produced as slender tapering struts (Fig.10E) that perhaps act as false gonapophyses, ovipositor membranous.
Description. General appearance elytrous, oval, convex body with a broad frons. Colour generally brown, veins of elytra pale in some species; eyes red in ethanol preserved specimens. Head declivent, height twice length in lateral view, broad in anterior view, without prominent setae except anteclypeus; anteclypeus, maxillary (Fig. 8C) and mandibular plates and bucculae (Fig. 8C) glabrous; eyes moderate size, 30–40% height of head, protruding to embrace lateral ends of pronotal collar, without setae; ocelli absent; vertex without macrosetae (no ocular macrosetae overhanging eyes), vertex abruptly (female) or gently (male) deflexed into inserted postocular part, which is visible only in distended specimens; inserted postocular part of the vertex weakly emarginate medially, broadest sublaterally (apodeme), tapering laterally to eyes; male frons broad, gently convex, with medial pore with (Figs 4A–E) or without (Figs 8C–D) salient dorsal hood; male frons if unhooded with 3–4 pairs of low, rugose, transverse carinae (Fig. 8C) marking cibarial muscle scars and interrupted medially creating shallow longitudinal furrow running anteriorly from pore or male frons if hooded with shallow furrow anterior to pore; female frons broad, with or without 3–4 pairs of low, rugose transverse carinae interrupted medially (Fig. 10C); maxillary plates distinctly larger than mandibular plates (Fig. 8C); anteclypeus roughly twice as long as wide, rectangular in anterior view, base weakly swollen but not salient, with one long slender macroseta centrally (150% anteclypeal width); labrum slender, reaching apex L2; labium stout, 3-segmented, reaching to mid coxae, without macrosetae but with several long, procurved setae, L1-3 roughly subequal, L1 broad, L3 tapering to point; bucculae widening and closed posteriorly but not posteroventrally salient (Figs 4C, 6B, 8C); gula half as long as height of eye (Figs 4C, 8C), without sutures or carinae; gena extensive ventral to eyes and antennal insertions, with gentle constriction near posterior margin projecting internally to prothorax and extending from gula to posterior margins of eyes (Fig. 4B, C). Antennae half as long as body, bases without tubercles, inserted at level of base of anteclypeus (Fig. 8C); A1 and A2 subequal, without macrosetae, A2 with corona of fine, short, apical setae, A3 weakly incrassate subbasally, weakly curved and 100–115% as long as straight A4, A4 not incrassate subbasally; A3–4 with long semierect fine setae up to half length of antennomere. Thorax. Pronotum weakly declivent; disc finely punctate in posterior half, flat to gently convex in lateral view, collar present and coplanar with disc, not embraced by disc in dorsal view, lateral margins rounded in cross section, in dorsal view straight and convergent, posterolateral angles rounded in dorsal view, not tumid; disc of mesoscutellum not depressed proximally, with pair of small, shallow pits medially, apex not posterodorsally salient in lateral view, apex minutely pinched in dorsal view; metascutellum inconspicuous; postnotal flange tiny, arcuate (Fig 4D); prosternum with roundly triangular shallow depression; proepisternal rims of fore coxal cavity narrow, cradling L 1 in repose; mesosternum with raised triangular area converging posteriorly bearing longitudinal sulcus (perhaps to accommodate labial apex), no salient process; metasternum with broad, short rounded process reaching halfway along hind coxae; metendosternite broad, apically briefly bifid; metapleura without spur-like lateral process at dorsal ends (unlike Silhouettanus Emsley 1969); posteroventral angles of metepisterna and metepimera rounded in lateral view (Fig. 5D). Fore wings elytrous, not overlapping, moderately convex; anterior furrow very short, claval furrow absent; veins weakly raised, bearing setae as long as vein width and spaced one vein-width apart plus dense microtrichae; cells with fine mosaic of tall microtrichae delimiting bare polygons (Fig. 7B); costal margin abruptly (D. cucullatus) or roundly (D. nubis) explanate and roundly reflexed to form epipleura; epipleura concave in cross section, twice as wide as dorsal view of explanate costal margin, as wide as hind tibial diameter, tapering to S6; most posterior vein of fore wing separated from hind margin by open cell broader than width of veins (Figs 2A, 7B, 10A); hindwings absent. Legs with male tarsal formula 3,3,3; female 2,2,3; tarsi slender except male fore and mid tarsi swollen; male fore and mid tarsi with membranous arolium; all tarsi with pair of parempodia as long as claws; claws slender, curved, with basal expansion; male fore and mid tarsi with subapical dorsal seta overhanging claws and reaching almost to apex of claws; fore tibiae with apical, ventral comb of 7–8 setae; mid tibiae with apical, posterior comb of four setae; hind tibiae without apical comb, with 4–5 sparse, ventral, fine, erect setae but without dense row of such setae; all tibiae without conspicuous macroseta except 4 or so apically and a few subapically on hind tibae, but with sparse, procumbent setae; femora without conspicuous macrosetae but with sparse, oblique setae; fore coxae with slender trochantin; hind coxae with rugose pad subapically on medial face. Male abdomen. S2–3 fused, gently contoured to hind coxae; S3–5 more or less symmetrical, without pairs of deep anterior incisions sublaterally; S6– 7 variously modified on right side to accommodate cylindrical accessory intromittent organ that projects anteriorly from genital capsule and also to accommodate right spiracular process of T8 (Figs 3A, 5B, 9B); spiracles on S6, S7 and T8; T1–2 fused; T3–6 lightly sclerotized, subrectangular sclerites almost reaching lateral margins; T7 large, heavily sclerotized, weakly skewed and asymmetrical, left third of disc impressed below plane of remainder (Fig. 9A). Female abdomen. S7 concave posteriorly, with small roundly triangular impression on posterior third (Fig. 10F), lateral margins weakly convex and converging posteriorly; female T8 squarely and deeply emarginate posteriorly, posterolateral angles project posteroventrally as tapering struts that perhaps act as false gonapophyses supporting the membranous ovipositor (Fig. 10E). Male terminalia. Male T8 sclerotized, broadly and roundly produced posteriorly on left side with left spiracle at apex of rounded projection (Fig. 9A), right spiracle at apex of tubular projection which is partly embraced by hemicyclindrical projection from left side of S7 (at least in D. acucullatus, Fig. 9A); genital capsule skewed to right (Fig. 9D), open anteriorly and posteriorly, with dorsal aperture weakly constricted at midlength (Fig. 3D); right paramere very long, slender and sinuous, reaching to left posterolateral angle of T7; left paramere small, with bulbous base, tapering with one concave face (Fig. 8E); both parameres with basal digit; anophoric sclerite in constriction of dorsal aperture of genital capsule, bearing more or less cylindrical process projecting anteroventrally to right to level of S6; this anophoric process with pair of short, proximal protuberances that perhaps articulate with right margin of capsule (Fig. 3D) and has complex internal structure including an irregular, spiral sclerite; basal plate short, contiguous with conjunctival sclerites (Figs 3D, 8F); conjunctival sclerites of uncertain number and detail; vesica a single, sinuous spine, apically bifid (Fig. 8F) or not (Fig. 3D), shorter than or subequal to right paramere, probably interacting with (entering) cylindrical anophoric process that acts as an accessory intromittent organ (Figs 5C, 9C). Female terminalia. T9 convex, anal aperture separated from deeply emarginate, deflexed, posterior margin by very slender bridge (D. nubis Fig. 10E) or from non emarginate posterior margin by one anal diameter (D. cucullatus); anal tube with three light sclerites.
Notes. The male genitalia of Dextritubus superficially resemble Semangananus Štys, 1974 and Vilhenannus Wygodzinsky 1950 in that an accessory intromittent organ projects anteriorly on the right side and the right paramere is very long. Dextritubus has no metasternal process unlike the conspicuous forked process of Vilhenannus Wygodzinky, 1950. Štys (1974) compared Semangananus with Dundonannus on several somatic characters (particularly venation and right digital process of T8 bearing a spiracle) but noted that the male accessory organ is fully sclerotized in the former but mostly membranous in the latter. The posterior marginal concavity of female S 7 in Dextritubus is reminiscent of cryptocephaline beetles and perhaps aids oviposition.
Type species. Dextritubus cucullatus sp. n. by present designation.
Distribution. Middle-east and south-east Queensland and the Australian Capital Territory.
Habitats. Collected by Berlese funnel litter extractions and flight intercept traps in open forest. Rare in 1300 samples of Schizopteridae collected by QM and ANIC, mostly from moist forest habitats of eastern Australia.
Etymology. From the Latin adjective dexter (right) and noun tubus (tube) alluding to the tubular accessory genitalia on the right side of the male. Gender masculine.
description: Published as part of Hill, Lionel, 2015, Three new genera of Schizopteridae from Australia with description of six new species (Hemiptera: Heteroptera: Schizopteridae), pp. 73-96 in Zootaxa 3990 (1) on pages 78-80, DOI: 10.11646/zootaxa.3990.1.4, http://zenodo.org/record/289123