Psephenops shepardi Arce-Pérez, 2013

Psephenops shepardi Arce-Pérez, 2013

Figs. 16–19 View FIGURES 16–23

Diagnosis. Adult male ( Figs. 16, 17 View FIGURES 16–23 ): body oval and depressed, head short, transverse, antenna long and moniliform; pronotum subtrapezoidal, anterior margin arcuate, posterior margin bisinuate as wide as elytral base, lateral margins straight along anterior half and expanded laterally on posterior half. Pronotal disc with median longitudinal carina well developed on distal half. Protibia with a denticle and tarsal lobes short. Male genitalia ( Figs. 18, 19 View FIGURES 16–23 ): short, wide, subrectangular, trilobate with parameres subparallel in apical third, medial margin of each paramere separated by wide U-shaped cleft, with tips of parameres not truncate and not divergent, basal half of parameres fused, ventral sclerite of penis subtriangular with apex bifid.

Material examined. MEXICO: Chiapas: Pichucalco, Tectuapan , 17°28’58.0”N, 93°06’53.0”W, 46 m, [?]. v.2017, Castillo-Uzcanga, Espinoza-Toledo, 2 males, Surber sampler (ECO-TAP-E) GoogleMaps ; Pichucalco , sitio experimental de INIFAP, 17°33’30.9”N, 93°03’26.2”W, 54 m, 29.v.24, Chacón-Hartleven, 2 males (ECO-TAP-E) GoogleMaps ; Ixtacomitán ( 17°25’39.93”N, 93°05’34.98”W), 193 m, 30.v.2024, 1 male (ECO-TAP-E) GoogleMaps ; Veracruz: Los Tuxtlas , 18.vi.1985, Muñoz, 1 male ( CNIN) ; same data except 18.v.2015, Contreras-Ramos, 1 male, D net ( CNIN) ; Los Tuxtlas, Río Máquinas , 18°37’16.0”N, 95°05’26.6”W, 21 m, 29.iv.2016, Contreras-Ramos, 9 males, D net ( CNIN) GoogleMaps .

Geographical distribution. BELIZE, Cayo and Toledo districts ; MEXICO, Chiapas and Veracruz states - first records for the country .

Habitat. Specimens from Tectuapan, Chiapas, were collected in fast-flowing zones of wadable streams in the Pichucalco River sub-basin, a tributary of the Grijalva River. Two specimens were collected in rapids of a stream that drains areas of cultivated pasture, where water temperature was 27.16 °C (± 2.14 SD) and dissolved oxygen concentration was 8.31 mg /L (± 1.04 SD). The stream had a good physical habitat condition (RBP = 0.67), with channel elements dominated by habitats with fast-flowing water, specifically rapid zones (40% of reach sampled) and inorganic substrates dominated by cobble and gravel (40% and 35% of reach sampled, respectively) ( Espinoza-Toledo 2018). Two specimens were collected in riffles of a stream that drains areas of pristine primary forest with abundant riparian vegetation, where water temperature was 28.65 °C (± 0.35 SD) and dissolved oxygen concentration was 6.61 mg /L (± 0.29 SD). This stream had an excellent quality of physical habitat (RPB = 0.95), with channel elements dominated by riffle and rapids zones (>65% of reach sampled) and inorganic substrates dominated by cobbles (70% of reach sampled). The specimen from Ixtacomitán, Chiapas, was collected in riffles of a stream from the Pichucalco River sub-basin, a tributary of the Grijalva River, running through human settlements. The stream presented a moderate physical habitat condition (RBP = 0.60), with direct wastewater discharge into the channel and abundant inorganic and organic waste materials; despite abundant riparian vegetation, anthropic contamination and alterations are evident. Channel elements were dominated by rapids (50 % of reach sampled), where water temperature was 26.71 °C (± 0.23 SD), dissolved oxygen concentration was 7.13 mg /L (± 0.34 SD), and inorganic substrates were dominated by pebbles and sand (50% and 30% of reach sampled, respectively).