Psephenops shepardi, Arce-Pérez, Roberto & Novelo-Gutiérrez, Rodolfo, 2013

Arce-Pérez, Roberto & Novelo-Gutiérrez, Rodolfo, 2013, Two new species of Psephenops Grouvelle from Belize (Coleoptera: Byrrhoidea: Psephenidae), with a key to the known species from Mexico and Central America, Zootaxa 3670 (1), pp. 63-70 : 66-69

Psephenops shepardi sp. nov. Arce-Pérez

( Figs. 1 b, 5–7)

Description. Holotype Male: Body oval, depressed; integument yellowish-red, with yellow iridescence, completely covered with iridescent, reddish-yellow, short setae. Head, antennal flagellum, scutellum and elytra dark yellowish-red; pronotum and legs light yellowish-red. Venter dark yellowish-red, vestiture short, fine and dense, gray-yellowish with reflections yellow. Head: short, transverse; clypeus subrectangular, declivous at an angle of less than 90 degrees from the plane of the frons, distal margin widely emarginate; fronto-clypeal surface with stout, dark reddish setae; vertex minutely punctate, with minute setae and very shallow longitudinal furrow in middle. Antennae moniliform, 11-segmented, scape yellow, larger than other segments, pedicel yellow, subglobose, half as long as scape; flagellum with 8 small segments, apical segment acuminate. Eyes lateral, rounded, very prominent, black, with a yellow post-ocular area. Labrum similar to clypeus but shorter. Maxillary palpi 4-segmented, covered with short setae, segment 1 smallest, apical segment largest, relative proportion of segments: 0.4, 0.9, 0.7, 1.0; basal segments 1–3 subconical, segment 4 oval, inflated from the base and gradually narrowing to tip (acuminate). Labial palpi very short, 3-segmented, segments 1–2 rounded and wide, segment 3 subconical, slightly shorter than preceding ones. Thorax: Pronotum light reddish-brown (dark reddish-brown in some paratypes), subtrapezoidal; anterior margin arcuate, posterior margin bisinuate, almost as wide as elytral base; lateral margins straight along anterior half and expanded laterally on posterior half; posterolateral angles subacute; all margins narrowly rimmed. Pronotal disc with median longitudinal carina well developed on distal half, and wide, shallow, circular depression at each side of carina; in profile view, pronotal disc (except for posterolateral expansions) convex; pronotal surface without punctation, covered with short, grayish-yellow setae, shorter than those of head. Scutellum short, with apex rounded. Elytra: with short reddish-yellow setae; sides parallel in basal 0.75, then gradually converging rearward; base lightly depressed on internal side of humeri. Prosternum short and slightly carinate, with short, lanceolate, slightly carinate prosternal process, not reaching anterior half of mesoventrite. Mesoventrite short, with wide groove for reception of prosternal process. Metaventrite large and bulky. Legs: procoxae globose, mesocoxae conical, metacoxae transverse; femora robust; tibiae slender, metatibiae longer than femora, protibiae with distinct, apicolateral denticle. Tarsi 5-segmented ( Fig. 1 b), tarsomeres 1 and 2 lobed ventrally, with a thick sponge-like vestiture; ventral lobe of tarsomere 1 extending distally over basal 0.25 of tarsomere 2; tarsomere 2 the longest, twice as long as tarsomere 1, extending distally and completely covering tarsomeres 3, 4, and basal 0.70 of tarsomere 5; proportional length of tarsomeres: 0.50, 1.0, 0.2, 0.2, 0.57; a pair of long, curved, slender apical claws, with small basal tooth. Abdomen: vestiture short, fine, dense, with yellow iridescence and intermingled dark reddish setae. Seven visible sterna (ventrites) in relaxed specimens; usually ventrite VI hidden under ventrite V; ventrite II the largest. Posterior margin of ventrite I deeply concave at middle, sinuate at sides; posterior margin of ventrite II as in ventrite I but concavity shallow medially; posterior margin of ventrites III and IV straight, ventrite V with wide, shallow concavity, ventrite VI very short, posterior margin widely concave. Pygidial plate oval, long, narrow and densely covered with a long, stiff, dark reddish setae. Genitalia: short, wide, subrectagular, trilobate ( Figs 5–7 ). Parameres robust, slightly shorter than median lobe, in dorsal view ( Fig. 5 ) with internal margins fused at basal 0.66, apices broadly separate, U-shaped, external margin abruptly and strongly convergent with the internal margin at 0.80 of parameres length, ending in a sharp point, with lateroapical membrane ( Fig. 5 ); in ventral view with small tooth on internal margin near apex ( Fig. 6 ). Penis, in ventral view, subrectangular, wider and longer than parameres, external margins concave, apical margin strongly convex with apical membrane ( Fig. 6 ), bearing longitudinal, ventral, subtriangular sclerite which is 0.54 as long as penis; dorsal area of phallobase concave ( Fig. 5 ); ventral portion bulky, subrectangular ( Fig. 6 ).

Measurements (in mm) [in square brackets the paratypes variation N=25]: Total length 2.65 [2.5-3.0, mean=2.65]; maxillary palp: 0.04, 0.09, 0.07, 0.10. Pronotum: posterior margin 0.98 [0.92-1.02, mean=0.97], lateral margin 0.44 [0.42-0.55, mean=0.47]; elytra: humeral width 1.16 [1.0-1.16, mean=1.10]; length of tarsomeres: 0.14, 0.28, 0.05, 0.05, 0.16. Genitalia: total length 0.46; parameres 0.28, penis 0.31; phallobase: length 0.20, width 0.16.

Type material. Holotype labeled: Belize: Cayo Dist, 1.7 mi E. O. Top, Camp, 9-I-1995, trib to Dr/Creek, WDS-A-1127 (EMEC), paratypes, same data as holotype 14 3 [9(IEXA); 5 3 (EMEC)]; Cayo Dist, Over the Top Camp, 9-I-1995, St Margaret ‘s Cr, WDS-A-1126,1 3 (IEXA); Toledo Dist., 35.1 km SE Belmopan, 3-Vlll-1993, unnamed stream, WDS-A-985, 4 3 [2 (IEXA); 2 (EMEC)]; Toledo Dist., Hellgate, 11-I-1995, WDS-A-1138, 13 (EMEC); Belize Dist., 3 mi W Gales Point, 14-I-1995, Soldier Creek, WDS-A- 1143, 4 3 (EMEC)..

Type locality. Belize; Cayo District, 1.7 mi east of Over the Top Camp on the Hummingbird Highway, tributary to Dry Creek, 115 m.

Etymology. This species is respectfully dedicated to Dr. William D. Shepard for his great contribution to the study of aquatic Coleoptera .

Remarks. Psephenops shepardi sp. nov. can be separated easily from other known Psephenops species by the following features [other species in brackets]: antennae moniliform [filiform, lupita ]; pronotum without tubercles [with 3 small tubercles, grouvellei ]; protibiae with denticle [without denticle, prestonae ]; tarsal lobes short [tarsal lobes enlarged maculicollis , mexicanus , prestonae , spiniparameri sp. nov.]. By general morphology and male genitalia P. s h e p ard i sp. nov. appears closely related to P. maculicollis and P. p re s t o n a e. P. shepardi sp. nov. is currently known from lotic regions 2 and 3 of Belize (sensu Shepard 2004).

Figures

FIGURE 1. Hind tarsi of Psephenops, dorsolateral view: a) P. spiniparameri sp. nov.; b) P. shepardi sp. nov.

FIGURES 5 – 7. Male genitalia of Psephenops shepardi sp. nov.: 5) phallobase, parameres and median lobe (penis), dorsal view; 6) same, ventral view; 7) same, lateral view.