Pspehenops triangularis

Novelo-Gutiérrez, Rodolfo, 2017, Two new species of Psephenops Grouvelle (Coleoptera: Byrrhoidea: Psephenidae) from Panama, Zootaxa 4323 (1), pp. 109-118: 114-115

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Pspehenops triangularis

sp. nov.

Pspehenops triangularis  sp. nov.

( Figs 9–16View FIGURES 9 – 12View FIGURES 13 – 16)

Type material. Holotype male labeled: PANAMA: Province of Panama; Chame District Río Marías , 325 m a.s.l., (08°38.020’ N, 80°01.510’ W), 26 April 2015, R. Novelo col. ( IEXA)GoogleMaps  . Paratype, 1 m #, same data as holotype ( IEXA).GoogleMaps 

Description. Holotype Male: Total length, 2.50 mm; humeral width, 1.0 mm. Body oval, depressed; integument dark red, head black; pronotum yellowish-red, darker on disk; elytra reddish-yellow, completely covered with short yellow setae with golden reflections, intermingled with dark red long setae ( Fig. 9View FIGURES 9 – 12); coxae, trochanters and femora reddish-yellow; tibiae, tarsi and venter dark red, vestiture short, fine and dense yellowishgray, with golden reflections ( Fig. 10View FIGURES 9 – 12).

Head: Short, transverse; clypeus subrectangular, declivous at an angle of less than 90 degrees from the plane of the frons, distal margin widely emarginated; fronto-clypeal surface and vertex with short yellow setae and long, dark red setae, vertex minutely punctate. Antennae short (e.g. when fully extended backwards, not reaching posterior margin of pronotum), moniliform, 11-segmented; scape longest, pedicel 0.50 length of scape and subglobose, third antennomere subtriangular and shorter than pedicel, antennomeres 4–10 small, moniliform, apical antennomere acuminate; scape and pedicel yellow ( Fig.11View FIGURES 9 – 12). Eyes lateral, rounded, very prominent, dark red, with a yellow post-ocular area. Labrum subrectangular, similar to clypeus but shorter. Maxillary palpi 4- segmented, covered with short setae; basal palpomere smallest, apical palpomere largest, relative length of palpomeres: 0.04, 0.6, 0.05, 0.11; palpomeres 1–3 subconical, palpomere 4 acuminate. Labial palpi very short, 3- segmented, palpomeres 1–2 rounded and wide, palpomere 3 subconical, nipple-shaped, slightly longer than preceding ones.

Thorax: Pronotum subtrapezoidal, almost as wide as elytral base; anterior margin arcuate, posterior margin bisinuate and 0.90 mm wide; lateral margin 0.52 mm wide, slightly curved along anterior half and expanded laterally on posterior half; posterolateral angles subacute. Pronotal disc with a well-developed, dorsomedial, longitudinal carina on the distal half, and a wide, oval, shallow depression to each side of carina; pronotal surface punctate, completely covered with short yellow setae, and long, dark red setae, more dense on disc ( Fig. 9View FIGURES 9 – 12). Scutellum short, wider basally than long, apex rounded. Elytra reddish-yellow, covered with short, yellow setae with golden reflections, and long, dark red setae ( Fig. 9View FIGURES 9 – 12); lateral margins parallel on basal 0.75, gradually converging posteriorly; humeral width 1.0 mm. Prosternum short, with anterolateral corners subtrapezoidal; prosternal process long and wide, flat, slightly carinate, with lateral margins not raised, ending in a lanceolate tip ( Figs 10–11View FIGURES 9 – 12) which reaches anterior half of mesoventrite. Mesoventrite shorter than metaventrite, with a wide groove for reception of prosternal process. Metaventrite large and bulky. Legs: Femora robust; tibiae slender, metatibia longer than metafemur, protibia with a tiny apicolateral denticle. Tarsomeres 1 and 2 ventrally lobed with a thick sponge-like vestiture; ventral lobe of tarsomere 1 extending distally over basal 0.30 of tarsomere 2; tarsomere 2 the longest, twice as long as tarsomere 1, extending distally and completely covering tarsomeres 3–4, and basal 0.80 of tarsomere 5; proportional length of tarsomeres: 0.50, 1.1, 0.18, 0.15, 0.55; apical claws long, curved, slender, each with a small basal tooth.

Abdomen: Vestiture short, fine and dense, yellowish-gray with golden reflections. Ventrite VI usually hidden under ventrite V; ventrites I and II wide, with posterior margin curved anteriorly in the middle; ventrite III with posterior margin curved posteriorly in the middle, ventrite IV narrow, with posterior margin straight; ventrite V with posterior margin slightly emarginate; ventrite VI very short, subtriangular, with posterior margin widely curved; ventrite VII or anal plate, oval, subtriangular, narrow, covered with long yellowish-gray setae ( Fig. 10View FIGURES 9 – 12); pygidium subtriangular covered with long dark red setae. Genitalia: Short, wide, subrectagular, trilobate ( Figs. 13– 14View FIGURES 13 – 16); total length, 0.46 mm; total width, 0.20 mm. Parameres robust, 0.25 mm long, longer than penis; internal margins fused in dorsal view ( Fig. 13View FIGURES 13 – 16), in ventrolateral view with an evident tooth on internal margin near to apex ( Fig. 16View FIGURES 13 – 16). Penis 0.21 mm long, shorter than parameres ( Figs 14–15View FIGURES 13 – 16); in ventral view finger-like, with a subtriangular lateral projection to each side of basal 0.50 of penis, bearing a short, wide, hourglass-shaped sclerite, which is 0.20 as long as the penis. Phallobase concave in dorsal view; bulky, subcylindrical in ventral view; length 0.23 mm, width 0.20 mm.

Variation. A specimen with a similar genital structure was collected, but with a yellow pronotum, and 10- segmented, yellowish-red antennae ( Figs 11–12View FIGURES 9 – 12). Paratype measurements (in mm) [N=1]: Total length, 2.45. Pronotum: posterior margin, 0.85; lateral margin, 0.50. Elytra: humeral width, 0.90.

Etymology. From the latin adjective “ triangularis  ” (with shape of triangle), this species is named triangularis  by the shape of the penis lateral projections.

Ecology. The two specimens of P. triangularis  sp. nov. were collected flying over turbulent rapids in the center of the stream, together with some specimens of P. bifidus  sp. nov.

Remarks. Psephenops triangularis  sp. nov. can be separated from other known Psephenops  species by the characteristics listed in Table 1.