Pseudomorychus, Lawrence, John F., Slipinski, Adam, Jäger, Olaf & Pütz, Andreas, 2013

Lawrence, John F., Slipinski, Adam, Jäger, Olaf & Pütz, Andreas, 2013, The Australian Byrrhinae (Coleoptera: Byrrhidae) with descriptions of new genera and species, Zootaxa 3745 (3), pp. 301-329 : 321-327

Pseudomorychus gen. n. (fig. 9)

Type species: Byrrhus torrensensis Blackburn 1889 .

Diagnosis. Described species of Pseudomorychus differ from all other Australian Byrrhinae in having functional hindwings; but they also have a somewhat more elongate body ( Figs 9 A, E) combined with well-developed postcoxal lines on the metaventrite ( Fig. 9 C) and relatively slender protibiae (FRig. 9D). P. mixtus is sometimes compared with Akidomorychus raucus in the literature and the two species are occasionally mixed in collections; however all species of Akidomorychus have distinctly expanded protibiae and spur-like gonostyli and lack postcoxal lines.

Description. Length 2.4–3.4 mm. Oblong to subovate; lateral outline more or less continuous; widest at or behind middle. Colour of dorsal surfaces usually black or dark reddish-brown, but head and pronotum metallic green in at least some P. torrensensis and lateral portions of pronotum and elytra yellowish-red or reddish-brown in some specimen; ventral surfaces and legs usually dark reddish-brown; antennae and palps somewhat lighter. Dorsal surfaces clothed with longer, suberect, fine yellow hairs and shorter, subdecumbent white hairs, the latter sometimes forming vaguely defined transverse bands on the elytra. Ventral surfaces with short, decumbent hairs.

Head slightly shorter than its width behind eyes, strongly declined and deeply inserted into prothorax, but with eyes at least partly visible; occipital region with short median endocarina; transverse occipital ridge absent. Eyes relatively small, not protuberant, located anteriorly. Frontoclypeal suture absent; frontoclypeal region moderately declined, obliquely vertical, delimited by complete transverse frontal ridge; antennal insertions barely concealed from above; subantennal grooves weak, extending to edges of eyes. Labrum relatively large and well sclerotized, with distinct transverse groove at base; apex broadly rounded or subtruncate. Antennae about as long as head width behind eyes, 11-segmented, with 4- or 5-segmented club; scape 2 to 3 times as long as wide, pedicel about half as long as and slightly narrower than scape (broad at base and narrowing apically in torrensensis ) and 1.5 times as long as wide; antennomere 3 slightly longer than to more than twice as long as 2, 3–3.5 times as long as wide; antennomeres 7-10 or 8–10 transverse and terminal antennomere at least slightly longer than wide. Mandible broad, subtriangular and obliquely tridentate; dorsal surface with distinct ridge fitting against sides of labrum; mesal surface of mandibular base without mola but with basal brush of hairs. Maxilla with short, setose galea and lacinia; apical maxillary and labial palpomeres elongate and apically truncate in P. torrensensis , more or less fusiform in P. mixtus . Subgenal ridges weakly developed. Gular sutures well separated; gula transverse; corporotentorium broad, straight; cervical sclerites well-developed.

Pronotum about 0.45–0.50 times as long as wide, widest at base; anterior edge broadly rounded or subtruncate but with weak emargination on each side; sides more or less straight and gradually narrowing anteriorly; anterior angles small and subacute; lateral carinae complete and sharply defined, broadest posteriorly and narrowing anteriorly, visible for their entire lengths from above; posterior angles acute and slightly projecting or right; posterior edge somewhat angulate or biemarginate forming mesal lobe, unmargined, with distinct posterior accessory ridge beneath; disc moderately to strongly convex with steeply sloping or bulging sides. Prosternum in front of coxae about 0.5 times as long as mid length of coxal cavity, slightly convex, with paired lateral antennal grooves and a concave head rest above. Prosternal process complete, parallel-sided or very slightly narrowing posteriorly and truncate or broadly rounded at apex. Procoxa more or less cylindrical, with well-developed exposed trochantin and weak coxal plate bearing tooth-like process; procoxal cavities strongly transverse, broadly open externally and internally. Notosternal sutures complete and anteriorly open. Hypomeron with moderately large, posterior crural impression for housing antennae and fore legs.

Scutellar shield moderately well developed. Elytra about 1.07–1.14 times as long as wide and 2.55–2.95 times as long as pronotum; sides weakly rounded anteriorly, more strongly so posteriorly; with distinct angulate humeri; disc strongly, more or less evenly convex; elytral apex with ventral interlocking tongue; epipleuron narrow but moderately long, extending just beyond metacoxae, very slightly concave anteriorly.

Mesoventrite strongly transverse, separated by complete sutures from mesanepisterna, which are very widely separated; anterior edge on different plane than metaventrite, with a pair of large, strongly declined procoxal rests continued onto mesanepisterna and with moderately deep mesoventral cavity; discrimen usually present just behind cavity. Mesoventral process short, broad and apically emarginate forming a pair of apicolateral condyles. Mesocoxae slightly transverse, with weak coxal plates and exposed trochantins. Mesocoxal cavities separated by 1.5–2 times shortest diameter of coxal cavity, partly closed laterally by mesepimera with mesanepisterna.

Metaventrite moderately short, its shortest length 1.65–1.75 times as long as shortest diameter of mesocoxal cavity; with curved postcoxal lines, extending from mesal third of mesocoxal cavity to about middle of lateral edge of metaventrite or recurved postcoxal lines outlining housings for mid legs; discrimen about half as long as ventrite; anterior metaventral process with pair of anterolateral cavities for receiving mesoventral condyles; exposed portion of metanepisternum about 3.3 times as long as wide, widest near anterior end; metepimeron concealed or slightly exposed. Metacoxae about 0.3 times as long as wide at base, not projecting, very narrowly separated, extending laterally to meet elytra, with well-developed, complete coxal plates. Metendosternite with moderately long, broad stalk, with or without slender laminae, with short, broad lateral arms and well-developed anterior process bearing well separated tendons. Hind wing well developed, about 2.85 times as long as wide; apical field about 0.64 times wing length, without distinct veins but with vaguely indicated longitudinal pigment patch; radial cell strongly skewed, about one-third as long as wide, with both basal and apical sides strongly oblique; cross-vein r3 very short and longitudinally oriented, well separated from r4, which is very lightly sclerotised; radio-medial loop acute; base of RP short; medial spur straight, ending well before wing margin; medial field with two complete free veins and two stubs; MP3+4 very short, with cross-vein and basal stub, sometimes absent; short stub of Cu present or absent; anal lobe moderately well-developed; AP undivided; anal embayment absent.

Legs relatively short, slender; femora slightly wider at basal third, without or with weak tibial impression; tibiae subequal in length to femora, slightly wider at apical third; outer edge lined with long, fine hairs and a few to several spine-like setae; apex with paired spurs. Tarsi 5-5-5, tarsomere 4 reduced, tarsomere 3 bearing a long, hyaline, setose ventral process longer than body of tarsomere; pretarsal claws simple.

Abdomen about 0.8 times as long as wide at base with five ventrites, the first three of which are connate; first ventrite with anterolateral corners slightly impressed and with moderately long, slender, intercoxal process, acute at apex; ventrite 5 about as long as 3 and 4 combined, broadly rounded at apex. Abdominal tergites lightly sclerotized or membranous. Functional spiracles on abdominal segments I–VIII. Anterior edge of sternite VIII in male with short, broad, rounded or truncate anterior projection. Sternite IX in male slightly elongate, rounded at base (anteriorly) and narrowly rounded to subacute, at apex (posteriorly); tergite IX transverse and undivided, broadly emarginate at apex. tergite X (proctiger) free, about as long as wide at base, broadly rounded at apex. Aedeagus with phallobase asymmetrical, strongly transverse with subtruncate lobe at base; parameres not diverging, broadest at base, gradually narrowed to subacute apex; penis slender, parallel-sided for most of its length, or very slightly widened subapically and then narrowed to apex, which is deeply cleft; basal struts short to moderately long. Anterior edge of sternite VIII in female biemarginate or with short angulate or truncate anterior process (spiculum ventrale), posterior edge broadly rounded; tergite VIII transverse and undivided; tergite IX consisting of paired laterotergites (paraprocts) connected at midline by a slender, lightly sclerotised strip. Female proctiger about as long as wide at base, broadly rounded at apex. Female proctiger slightly longer than wide. Ovipositor about 1.3 times as long as wide; paraprocts as long as to slightly longer than gonocoxites, each of which has an elongate, subcylindrical and lightly to moderately sclerotized distal lobe with an apical, lightly to moderately sclerotized gonostylus 0.4–0.5 times as long.

Etymology. Pseudos (Greek, n,), fallacy and the Holarctic genus Morychus . The name refers to the fact that P. torrensensis was placed in the genus Morychus by Blackburn (1903).

Included species. P. torrensensis (Blackburn 1889: 138) comb. n., P. mixtus (Lea 1907: 140) , comb. n.

Distribution. Widely distributed in Tasmania, Victoria, South Australia, the Australian Capital Territory and New South Wales.

Figures

FIGURE 9. Byrrhinae: Pseudomorychus spp.: A – C: P. mixtus (Lea): A, habitus, dorsal, Length = 2.3 mm; B, habitus, lateral; C. pterothorax, ventral, with left mesocoxa removed. D – E, P. torrensensis (Blackburn): D, fore leg; E, habitus, dorsal, length = 3.2 mm.