Pterydrias cattieni Falin and Engel

Falin, Zachary H. & Engel, Michael S., 2016, Two New Species of Pterydrias Reitter (Coleoptera: Ripiphoridae), Significantly Expanding the Biogeographic Range of the Genus, The Coleopterists Bulletin 70 (2), pp. 203-213 : 204-207

Pterydrias cattieni Falin and Engel , new species ( Figs. 1–4 )

Diagnosis. Male. Pterydrias cattieni is very similar to Pterydrias loebli (Batelka and Hájek) in that it is a comparatively small species with a short, transverse head in which the “temples [are] almost absent” (i.e., the compound eye nearly reaches the occipital ridge posteriorly), with the antennal cavity essentially contiguous with the margin of the compound eye ( Figs. 1, 4 ), and with very similarly proportioned apical maxillary palpomeres (palpomere IV being approximately 1.2X the combined length of palpomeres II and III) and elytral length to pronotal length ratio 2.3 ( Fig. 2 ). It differs from P. loebli in having the occipital ridge seemingly more sharply defined and the compound eye very closely approaching the ridge posteriorly ( Figs. 1, 3 ), thereby making the temples all but obsolete and creating a nearly straight appearance to the posterior margin of the compound eye ( Fig. 1 ). Furthermore, the pronotum of P. cattieni is more quadrate and parallel-sided with nearly right posterolateral angles ( Fig. 3 ), while that of P. loebli is more bell-shaped with acutely pointed, projecting posterolateral angles. The species is seemingly unique among other species of Pterydrias in the presence of distinctive setal patches on ventrites IV–VI (vide Comments, infra) ( Fig. 1 ).

Description. Male. General size and appearance typical for genus. Approximately 2.2 mm long in dorsal view from antennal bases to tip of more or less extended abdomen, 0.5 mm wide at base of pronotum; elytral length 1.0 mm, hind wing length approximately 1.0 mm. Integument shiny throughout (except antennae); body color various shades of brown ( Figs. 1–4 ): head darkest; pronotum and distal aspect of elytra slightly lighter brown; meso- and metanota, abdomen, ventral aspects of pterothorax, and elytral humeri lighter yet. Distal segments of maxillary palpi pale, tawny brown; ventral aspects of mouthparts paler. Antennomeres I–V same color as pronotum, VI–X lighter brown, XI appearing slightly darker than preceding. Elytra thinly sclerotized, not quite coriaceous. Hind wings lightly pigmented and covered with microsetae, adding to infuscate appearance and giving iridescent sheen.

Head as per diagnosis; comparatively short and transverse in dorsal view ( Fig. 3 ). Vertex nearly uniformly convex, flattening slightly towards occipital ridge; ventral aspect of head irregularly planar

2) Dorsal habitus; 3) Head and pronotum, dorsal view; 4) Head, frontal view.

(except for slight bulge from compound eyes), creating a roughly hemispherical profile. Integument densely, coarsely punctured with short, pale, suberect to erect setae dorsally ( Fig. 3 ); much less densely and more finely punctured with short, scattered, outwardly facing decumbent setae ventrally. Gular suture fused, appearing as an impressed sulcus terminating in a triangular pit defining base of submentum, which is otherwise fused with ventral buccal margin. Compound eyes coarsely faceted with very short, pale, erect setae ( Figs. 3, 4 ); bulging, occupying nearly entire lateral aspect of head ( Fig. 1 ), nearly reaching occipital ridge posteriorly, with only a thin strip of integument visible ventral to compound eye in lateral view, contiguous with antennal insertion antero-dorsally, and separated from maxillary insertions anteriorly by approximately 1 ommatidial width. Frons a narrow, blunt longitudinal ridge from antennal to mandibular insertions, concavely sloping laterally to anterior margin of compound eyes and maxillary insertions.

Mouthparts reduced, apparently non-functional. Labrum absent. Mandibles clearly articulating with frons and well-sclerotized, but simple, arcuate, appearing vestigial ( Fig. 4 ). Maxillae reduced, cardo and stipes appearing fused; galea and lacinia absent; palpi tetramerous (4 palpomeres), palpomere I minute, relative lengths of palpomeres II–IV as per diagnosis; palpomere IV compressed, basal 3/5 nearly parallel-sided, apical 2/5 obliquely truncate, margin of truncation with minute, specialized sensillae. Labial structures difficult to characterize, submentum fused to ventral buccal margin; prementum sclerotized but reduced, completely divided into lateral lobes; glossa and paraglossa fused, membranous, also divided into lateral lobes; labial palpi simple, 1 digitiform palpomere.

Antenna with 11 antennomeres, filiform ( Figs. 1, 2 ). Antennomere I broadest, subcylindrical, apical inner margin very slightly emarginate; antennomere II approximately 2/3 length of antennomere I, succeeding antennomeres gradually longer, antennomere XI longest of all and slightly compressed; antennomeres VI–XI appearing lighter in color than preceding antennomeres, apparently due to presence of specialized sensillae.

Pronotal punctation similar in strength but slightly less dense than that of vertex, with short, pale, posteriorly oriented, suberect setae. In dorsal view, pronotum comparatively quadrate ( Fig. 3 ); basal 1/4 slightly, evenly expanding posteriorly; median 1/2 parallel-sided; apical 1/4 evenly, strongly converging anteriorly. Anterior pronotal margin overlain dorsally by occipital ridge of head, approximately equal in length to distance between compound eyes in dorsal view. Posterior pronotal margin weakly bisinuate and dorsally produced medially ( Fig. 3 ), nearly straight laterally; posterolateral angles nearly right, not projecting ( Fig. 3 ). Lateral pronotal margins rounded, without bead, though basal 1/4 of propleurae dorso-ventrally compressed giving a sharp appearance to margin. Pronotal disc irregularly convex, a weak longitudinal ridge occupying medial 1/4, strongest basally with a pair of subtle convexities to either side of midline in basal 1/3, 2 additional small convexities antero-laterally, apparently demarcating internal articulation points of procoxae. Propleurae slightly less punctate than pronotum, narrow, without invagination dorsad procoxal insertions. Prosternum weakly punctate with scattered setae, trapezoidal, narrowly articulating with propleurae anteriorly; anterior margin shallowly, concavely arcuate, posterior margin obscure, appearing convexly arcuate; prosternal disc convex, without keel.

Mesonotal punctation slightly weaker than pronotum, with posteriorly oriented suberect setae; trapezoidal, anterior margin overlaid by posterior margin of pronotum, posterior margin straight, overlaying anterior margin of mesonotum forming a narrow mesoscutellum; mesonotal disc roughly planar except for weak longitudinal depression medially.

Metanotal configuration difficult to characterize, all but extreme medial aspect obscured by elytra and hind wings in holotype [descriptions from paratype (missing 1 elytron) noted below]. Metaprescutum absent; metascutum of paratype apparently divided into poorly sclerotized, concave anterolateral lobes and irregularly convex, wellsclerotized and weakly punctate posterolateral lobes. Metascutellum clearly delineated from posterolateral lobes of metascutum by a pair of sulci, sinuate in basal 1/3, converging to become closely parallel in apical 2/3, continuing to anterior margin of metanotum; broad basal portion of metascutellar disc convex, narrow apical portion depressed below level of postero-lateral lobes of metascutum. Metapostscutellum large, well-sclerotized with areas of indistinct, irregular surface sculpturing, without setae; separated anteriorly from metascutellum by a strong sulcus; depressed posteriorly; posterior margin convex, slightly thickened and deflected dorsally.

Lateral and ventral aspects of pterothorax more or less typical of subfamily; integument more finely, less densely punctate than pro- and mesonota (except metasternum impunctate), with scattered suberect setae. Mesepisternum apparently fused with obscured mesosternum; mesepimeron appearing as a rounded flange separated from mesepisternum by a deep, parallel-sided groove. Metepisternum elongate, subparallel, and widest in anterior 1/3, tapering to a point posteriorly; anterior margin straight, thickened, but dorso-anterior lobe absent. Metepimeron indistinct, reduced to a narrow sclerotized strip immediately dorsad metepisternum. Metasternum expanded as much or more so than typical of subfamily.

All leg podites distal to coxae missing from holotype and paratype; coxae typical of subfamily in form; lateral aspect of metacoxae nearly impunctate and glabrous, ventral aspect punctate and comparatively densely clothed in posteriorly facing suberect setae.

Elytral punctation and setation similar to mesonotum, integument shiny between punctures. Elytra widely separated, short, approximately length of metanotum when closed. Slightly deformed in preservation, lateral margins widening slightly and evenly to apical third, apex broadly, evenly rounded. Hind wings crumpled in preservation, venation difficult to characterize but appearing more or less typical for subfamily: vein R welldefined, fusing with C+Sc approximately halfway along its length and terminating prior to wing apex; veins Cu and 2 nd A 3 +3 rd A 1 also welldefined, former terminating just prior to wing margin, latter reaching margin.

Abdomen difficult to characterize due to preservational deformation, apparently with 7 (II–VIII) visible tergites and 6 (III–VIII) visible ventrites, roughly subequal in length to pterothorax in current preservational state. Form and degree of sclerotization of tergites II–V obscure, more or less convex dorsally; tergites VI–VIII well-sclerotized in comparison to basal ventrites, tergites VI–VII narrow, convex bands, tergite VIII also narrow, convex dorsally, apical margin evenly convex. Ventrites comparatively weakly sclerotized basally, shiny, weakly punctate with scattered, sort setae laterally, roughly semicircular in cross section. Ventrites III and V subequal to ventrite IV; ventrite VI slightly distorted, appearing approximately subequal to ventrite V; ventrite VII a narrow band, lateral aspect approximately 1/2 length of ventrite VI, apical margin broadly, shallowly excavate; ventrite VIII subequal to ventrite VII, tapering evenly towards apex, apex strongly excavate. Ventrites IV–VI each with a conspicuous medial patch of dense, suberect, pale setae occupying approximately apical half of ventral aspect of segment.

Genitalia of holotype and paratype hidden within abdominal tip.

Female. Unknown.

Immature Stages. Unknown.

Holotype. ♂; “ VIETNAM: Dong Nai / Cat Tien National Park, Dong Nai River, / 120 m / 11°26′33″N, 107°25′55″E / 23–31 May 1999; B Hubley, D.C. Darling / VIET1 H95-99 010 ex: malaise trap ” // “ SM0189802 / KUNHM-ENT ” // “ HOLOTYPE / Pterydrias / cattieni / Z.H. Falin & M.S. Engel ”; deposited in Department of Entomology , Royal Ontario Museum, Toronto, Canada.

Paratype. ♂; “ VIETNAM: Dong Nai 120 m / Cat Tien National Park, Ecology Trail / 11°26′22″N, 107°24′58″E / 25–31 May 1995; D. Darling, N. Talarnic / VIET1 H95-99 082 ex. malaise trap ” // “ SM0190419 / KUNHM-ENT ” // “ PARATYPE / Pterydrias / cattieni / Z.H. Falin & M.S. Engel ”; deposited in Division of Entomology , University of Kansas Natural History Museum, Lawrence, Kansas, USA.

Intraspecific Variation. The paratype’ s measurements are nearly identical to those of the holotype, though it appears smaller due to the body being considerably more flexed in preservation. Otherwise, it does not differ from the holotype in any appreciable manner.

Etymology. The specific epithet is derived from Cát Tiên National Park, the type locality for this species. It is intended to highlight the importance of parks and reserves in harboring and protecting rare species such as P. cattieni .

Comments. Pterydrias cattieni is known only from the holotype and paratype described above. The setal patches present on ventrites IV – VI are remarkable in that they appear to be absent, unrecorded, or obscured by preservation technique in all other species of Pterydrias .

Figures

Figs. 1–4. Pterydrias cattieni, holotype. 1) Lateral habitus (arrow points to lateral setal patch on ventrite V);