Mecyclothorax amingwiwae Liebherr, 2017

Liebherr, James K., 2017, Review of Mecyclothorax Sharp (Coleoptera: Carabidae: Moriomorphini) from Papua New Guinea, with Descriptions of Five New Species, The Coleopterists Bulletin 71 (4), pp. 679-703 : 697-699

11. Mecyclothorax amingwiwae Liebherr , new species ( Figs. 8 , 32 )

Diagnosis. The convenient diagnosis of quadrisetose pronotum, presence of the parascutellar seta, and presence of two dorsal elytral setae restricted to the third interval uniquely diagnoses this species within the Papua New Guinea Mecyclothorax fauna. Mecyclothorax amingwiwae can also be distinguished by its pronotal configuration including the deeply canaliculate anterior transverse impression, broadly explanate lateral margin inside and anterad the hind angle, the smooth laterobasal depressions with a median tubercle, and the distinctly depressed, strigosely punctate median base. The anterior transverse pronotal impression is deeply and finely incised, continuous between the only slightly protruding and rounded pronotal front angles ( Fig. 8 ). The elytral striation is much like that observed in M. gressitti , with discal striae 1–4 shallow with elongate punctures, striae 5–6 comprising serially isolated punctures, and stria 7 evidenced by only the shallowest of impressions, discontinuous along its length. However, unlike M. gressitti , the elytral microsculpture of M. amingwiwae is a mixture of transversely stretched isodiametric and transverse sculpticells, their breadth 3X length. The pronotal shape with broader lateral margins outside the laterobasal depressions is shared with M. kubor , however, that species lacks the canaliculate anterior transverse impression and is characterized by five dorsal elytral setae ( Baehr 2008). Standardized body length is 4.2 mm.

Description. Head: Gracile; compound eyes large in diameter and little convex, hind margin of eye nearly touching gena ( Fig. 6 ), ocular ratio = 1.57, ocular lobe ratio = 0.97; frontal grooves deep, moderately broad, subparallel, terminated posteriorly just behind and mesad anterior supraorbital seta, meeting finely incised frontoclypeal suture at small pit, a finely incised and independent groove extending forward onto clypeus from point mesad frontal groove-frontoclypeal suture juncture; juncture of compound eye and gena defined by finely incised groove; antennomere 3 with a few fine setae basad apical ring setae; antennomeres broad, robust, antennomere 9 length 2.0X maximal breadth; anterior labral margin broadly, moderately emarginate; mandibles moderately elongate, length from dorsal condyle to apex 1.6X distance from condyle to anterolateral margin of labrum; vertex with broad, shallow, transverse depression behind eyes; mentum tooth with sides acute, apex tightly rounded; ligular apex truncate, ligular setae separated by 2 setal diameters, paraglossae extended only 1/4 length past anterior ligular margin. Pronotum: Broad, lateral margins broadly convex, base broad, MPW/BPW = 1.39, MPW/PL = 1.27; lateral setal position 1/2–1 setal diameter inside lateral marginal depression; hind angles represented by a small hitch in the otherwise convex lateral and basal margins, basal pronotal seta situated just anterad hitch; median base distinctly depressed relative to disc, about 16 shallow punctures each side, juncture of median base and disc lined with very fine punctures laterally, smooth medially; basal margin broadly upraised behind laterobasal depressions, convex medially, margin trisinuate with convex portions behind each depression and medially; median longitudinal impression with narrow, deep impression at front of median base, finely incised, nearly obsolete on disc; anterior transverse impression deeply incised across entire pronotal breadth, anterior callosity flat, slightly longitudinally wrinkled; front angle slightly protruding, rounded, marginal bead well-defined there; lateral marginal depression narrow anteriorly, broader behind lateral seta, smoothly broadened to laterobasal depression, distinctly lined with microsculpture throughout its length, margin beaded anteriorly, explanate posteriorly; laterobasal depression broad, a broad convex tubercle between lateral marginal depression and punctate median base; prosternum with smooth, deep anteapical furrow that extends from lateral reaches across ventral surface; prosternum flat medially posterad anteapical furrow, broadly, slightly concave between procoxae; proepimeron with anterior and posterior grooves smooth. Elytra: Broadly ellipsoid, humeri narrowly rounded, maximal width about midlength ( Fig. 8 ), MEW/EL = 0.74; parascutellar seta present; scutellum broad, width at transverse groove/median length = 2.2; parascutellar striole shallow, smooth; basal elytral groove distinctly recurved anteriorly from striole, humeri obtusely angulate; sutural stria deep, smooth, striae 2–5 shallow, intermittently defined by elongate punctures; striae 6–7 obsolete, 6 represented by few very isolated punctures, 7 by a more continuous but shallow impression; well-developed sutural stria and obsolete stria 2 present on elytral apex only, other irregular depressions may be due to teneral nature of type specimen; stria 8 smooth along midlength, although incoherent near impressions associated with lateral elytral setae; lateral marginal depression very broad laterad anterior series of lateral elytral setae, progressively narrowed behind; subapical sinuation broadly, slightly invaginated, epipleuron visible in anterior portion; lateral elytral setae 7 + 6; subapical elytral seta absent, apical seta in association with apex of stria 2 present. Mesepisternum: With 10 shallow punctures in 1–2 dorsoventral rows, 3 punctures aligned each side of mesosternum; metepisternum maximum width/lateral length = 0.88; metasternal process acute, apex with knob-like extension, knob depressed at base, lateral margins narrowly convex; metathoracic wings vestigial, apex not extended beyond posterior margin of metanotum. Abdomen: Ventrites 1 and 2 separated by broadly sinuous suture laterally, surface of ventrite 2 depressed posterad sinuosity; suture between ventrites 2 and 3 shallow but traceable laterally; longitudinal wrinkles present laterally on ventrites 2–3, broad shallow depressions present laterally on ventrites 3–6. Microsculpture: Reduced on head, frons and vertex glossy with shallow, transverse mesh, sculpticell breadth 3–4X length on frons, 2–3X on vertex; pronotal disc and base glossy, indistinct transverse lines visible in areas of reflection, laterobasal depression and lateral marginal depression lined with mix of isodiametric and transverse sculpticells; elytra with evident transverse mesh, sculpticell breadth 2–4X length, surface subiridescent; elytral apex glossy, indistinct transverse mesh visible in irregular depressions of surface; metasternum with an evident transverse mesh, sculpticell breadth 2–3X length; lateral portions of basal abdominal ventrites with swirling isodiametric and transverse sculpticells. Coloration [teneral specimen]: head dark rufous, vertex slightly paler, rufobrunneous, labrum and mouthparts brunneous; antennae rufoflavous, antennomeres 4–11 with piceous cast; pronotal disc rufobrunneous, lateral marginal depression rufoflavous; elytral disc rufobrunneous, sutural interval concolorous, lateral marginal depression flavous; proepipleuron rufoflavous, proepisternum rufobrunneous; elytral epipleuron rufoflavous, metepisternum flavobrunneous; abdomen rufobrunneous medially, broadly rufoflavous laterally, apical half of ventrite 6 flavous; femora rufoflavous, tibiae rufobrunneous.

Female Reproductive Tract. The holotype female is somewhat teneral, and attempts to gently extrude the gonocoxites for scoring of ovipositor characters were unsuccessful. As teneral females usually do not provide sufficiently sclerotized female tracts to permit elucidation of fine structures associated with the bursa copulatrix and spermathecal assembly, the holotype was not dissected.

Holotype. Female ( BPBM): NEW GUINEA NE / Mt.Amingwiwa 3000– / 3400m 12.IV.1970 / J.L. Gressitt / Collector / BISHOP MUSEUM // HOLOTYPE / Mecyclothorax / amingwiwae / J.K. Liebherr 2017 [black-bordered red label].

Etymology. This species is named for the type locality as labeled by J. L. Gressitt, using the first declension singular genitive form, amingwiwae, to mean Mt. Amingwiwa’ s Mecyclothorax .

Distribution and Habitat. J. L. Gressitt collected the unique type at 3,000 –3,400 m elevation on what he called Mt. Amingwiwa. This spelling is an unapproved variant of Mt. Amung, the approved name for this mountain, with Mt. Amungwiwa a recognized variant ( National Geospatial Intelligence Agency 2017; Fig. 32 ). Thus, the type locality is designated Mt. Amung, Morobe Province. The elevation of the type locality is consistent with elfin or dwarf forest habitats on other nearby mountains, such as Mt. Kaindi ( Gressitt 1970). Along with the holotype of M. amingwiwae, Gressitt also collected the holotype and some associated paratypes of Cryptolaemus splendens Poorani, Ślipiński, and Booth (Coccinellidae) ( Poorani et al. 2014) ( Coccinellidae ). On the same trip to this locality, he collected a pair of Apirocalus sedlaceki laminifer Thompson (Curculionidae) , labeling them “ 1000-2300 m, 12–13.iv.1970 ” ( Thompson 2005), suggesting that he spent the night of 12 April at high elevation, having hiked up that day, and then hiking back down toward Wau on 13 April.

Figures

Figs. 5–8. Mecyclothorax species, dorsal habitus. 5) M. brispex; 6) M. gressitti; 7) M. sedlaceki; 8) M. amingwiwae. Range of standardized body lengths (in mm) and setal formulae (see text) for number of supraorbital setae each side, number of pronotal setae each side, number of dorsal elytral setae each elytron, and number of setae at the apex of each elytron are indicated.

Fig. 32. Localities in Papua New Guinea from which Mecyclothorax spp. were collected and the particular species collected at each locality. 1 = Mt. Capella — M. baehri; 2 = Mt. Fugilil — M. brispex and M. medioconstrictus; 3 = Kubor Range — M. kubor; 4 = Mt. Wilhelm — M. sedlaceki; 5 = Finisterre Range — M. kavanaughi; 6 = Mt. Missim — M. gressitti; 7 = Mt. Kaindi, Edie Creek and Bulldog Road — M. andersoni, M. cuccodoroi, and M. loebli; 8 = Mt. Amungwiwa—M. amingwiwae.