Belladessus femineus Miller and Short, 2015

Miller, Kelly B. & Short, Andrew E. Z., 2015, BelladessusMiller and Short (Coleoptera: Dytiscidae: Hydroporinae: Bidessini), New Genus for Two New Species from Northern South America: Parthenogenetic Diving Beetles?, The Coleopterists Bulletin 69 (3), pp. 498-503 : 501-503

Belladessus femineus Miller and Short , new species

( Figs. 1–3 , 7 , 8A )

Type Locality. Suriname, Sipaliwini District, Tafelberg Summit, near Caiman Creek Camp, 3°53.942′N 56°10.849′W, 733 m.

Diagnosis. From B. puella , this species differs in having the anterior clypeal margin thicker, the modification to the clypeal margin less distinct, and the dorsal color pattern with the maculae less well-defined and more broadly distributed.

Description. Measurements: TL = 2.0– 2.1 mm, GW = 1.1–1.2 mm, PW = 1.0– 1.1 mm, HW = 0.6–0.7 mm, EW = 0.4–0.5 mm, TL/GW = 1.7–1.8, HW/EW = 1.4–1.5. Body relatively globular, lateral margins broadly rounded, apex rounded ( Fig. 1 ). Coloration: Head orange-yellow ( Fig. 1 ). Pronotum yellow, lighter in color than head, darker orange along posterior margin. Elytra brown-red with pale yellow maculae as follows ( Fig. 1 ): a transverse, subbasal, undulating macula; a medial, subsutural, small macula; a medial, submarginal macula; and a subapical, transverse macula. Antennae, palps, and legs orange. Venter orange to orange-red on most surfaces, slightly darker along sutures. Sculpture and structure: Head transversely broad, anterior clypeal margin broadly curved, distinctly expanded and indistinctly but broadly margined; surface with sparse, extremely fine punctures and weakly evident microreticulation; occipital line absent; eyes large; antennomeres I-II moderately elongate, III-XI short and broad. Pronotum broad, widest at posterior angles ( Fig. 1 ); lateral bead fine and continuous; surface shiny, covered with extremely fine punctures. Elytra short and broad, apices rounded ( Fig. 1 ); surface with sparse, fine punctures; sutural stria absent; elytral epipleuron without transverse carina at humeral angle. Prosternum medially tectiform and setose; prosternal process moderately broad, lateral margins parallel; margins carinate, medially longitudinally strongly canaliculate; apex rounded. Metasternum smooth, shiny, impunctate except on metasternal wings with few, indistinct punctures. Legs shiny, relatively impunctate; metatrochanter large, slightly offset from midline of metafemur ( Fig. 2 ); metacoxa shiny, with few, indistinct punctures. Abdomen shiny, with few punctures, mainly near sutures; apex of ventrite VI broadly pointed. Female genitalia: Gonocoxae elongate, apically elongate triangular, anteriorly with elongate apodemes ( Fig. 3 ); bursa moderately large, rounded; spermathecal duct very long, basally broad, narrowed there- after and extremely long and narrow, expanded near receptacle; receptacle globular with small posterior, pointed lobe; spermatheca globular with prominent internal spermathecal spine; fertilization duct subtended by large, broad flange, duct short and slender.

Variation. Specimens vary somewhat in the extent and degree of coloration on the elytron, with the maculae relatively expanded or reduced.

Etymology. The species is named femineus, Latin adjective for “feminine,” after its evidently parthenogenetic reproductive strategy.

Distribution and Habitat. This species is known from Sipaliwini District in Suriname and Bolívar State in Venezuela ( Fig. 7 ). All specimens were collected in forested habitats, primarily from small stream margins and stream-associated pools ( Fig. 8A ), usually with abundant detritus. They were collected at 320–879 m elevation. The majority of specimens were collected from the summit of Tafelberg, the easternmost and one of the most isolated of the Guiana Shield’ s table mountains (tepuis).

Discussion. This species was collected from two relatively distant localities, central Suriname and Bolívar State in southeastern Venezuela. Specimens from these two populations are, however, extremely similar.

Belladessus femineus and B. puella are similar in size, shape, and other features, but differ in coloration and degree of modification of the anterior clypeal margin. Since males do not exist or are not known, usual dytiscid diagnostic characters (male primary and secondary sexual attributes) are not available. Nevertheless, the broadly disjunct distribution ( Fig. 7 ) and consistently different coloration and clypeal characters are consistent with two different species.

Type Material. Holotype in NZCS, male labeled, “ SURINAME: Sipaliwini District N3°55.600′ W56°11.300′, 600m CSNR: Tafelberg Summit, near Augustus Creek Camp rocky creek; leg. Short & Bloom 22.viii.2013; SR13-0822-01B/ SEMC1080378 KUNHM-ENT [ SEMC barcode label]/ HOLOTYPE Belladessus femineus Miller and Short, 2015 [red label with black line border].” Paratypes, 121 total, all with label, “ PARATYPE Belladessus femineus Miller and Short, 2015 [blue label with black line border]:” and with SEMC numbers ( Table 1); 61 labeled same as holotype; 2 labeled same as holotype except “…pooled up detrital forest stream…” and “…SR13-0819-05A…;” 7 labeled labeled same as holotype except “…stream margins…” and “… 18.viii.2013; SR13-0818-01A…;” 1 labeled same as holotype except “…small forest stream…” and “…SR13-0819-03A…;” 1 labeled same as holotype except “…small streams with lots of plants & leaf litter…” and “… 18.viii.2013; SR13-0818- 03A…;” 1 labeled “ SURINAME: Sipaliwini District N3°47.479′ W56°08.968′, 320m CSNR: near Kappel airstrip forested stream & stream pools leg. Short & Bloom; 24.viii.2013 SR13-0824-03A;” 21 labeled, “ SURINAME: Sipaliwini District N3°55.600′ W56°11.300′, 600m CSNR: Tafelberg Summit nr Augustus Creek Camp 17.viii.2013; SR13-0817-03A;” 2 labeled same as previous except “…forested creek margins…” and “… 22.viii.2013 SR13-0822-02B…;” 2 labeled same as previous except without habitat information and “… 17.viii.2013; SR13-0817-03A…;” 6 labeled, “ SURINAME: Sipaliwini District N3°53.359′ W56°10.052′, 879m CSNR: Tafelberg Summit near South Rim, small seep/ streamlet; leg. Short & Bloom 20.viii.2013; SR13-0820-01D; 13 labeled, “ SURINAME: Sipaliwini District N3°53.592′ W56°10.849′, 733m CSNR: Tafelberg Summit, nr Caiman Creek Camp , pools in forest; leg. Short & Bloom 19.viii.2013; SR13-0819-05B;” 7 labeled, “ VENEZUELA: Bolivar State 4°28.233′N, 61°35.559′W, 867 m Gran Sabana , Pauji : Esmerades 16.vii.2010;leg. Short, Tellez , Arias detrital pools by forested stream VZ10-0716-02A;” 2 labeled, “ VENEZUELA: Bolivar State 4°28.782′, 61°34.904′W, 853m 1 km E Pauji, trib. of Rio Pauji 16.vii.2010;leg. Short, Tellez, Arias along stream; VZ10-0716-01A.”

Belladessus puella Miller and Short , new species ( Figs. 4–6 , 7 , 8B )

Type Locality. Venezuela, Barinas State, ∼ 13 km NW Barinitas , 8°48.424′N, 70°31.139′W, 992 m.

Diagnosis. This species differs from B. femineus in having the anterior clypeal margin more distinctly modified with the marginal bead thinner and more strongly marked and the dorsal color pattern with the maculae well-defined and less broadly distributed, restricted to two large, vivid maculae ( Fig. 4 ).

Description. Measurements: TL = 2.0– 2.1 mm, GW = 1.1–1.2 mm, PW = 1.0– 1.1 mm, HW = 0.6–0.7 mm, EW = 0.4–0.5 mm, TL/GW = 1.7–1.8, HW/EW = 1.4–1.5. Body relatively globular, lateral margins broadly rounded, apex rounded ( Fig. 4 ). Coloration: Head brown-yellow to orange-yellow ( Fig. 4 ). Pronotum yellow, lighter in color than head, slightly darker along posterior margin. Elytra brown-red with pale, yellow maculae as follows ( Fig. 4 ): a transverse, subbasal, undulating macula; a mediolateral macula narrowly confluent with subbasal macula in most specimens; and a subapical macula broadly extending anteriorly along the lateral margin. Antennae, palps, and legs orange. Venter yellow to yellow-orange on most surfaces, slightly darker along sutures. Sculpture and structure: Head transversely broad, anterior clypeal margin broadly curved, slightly expanded, indistinctly and moderately narrowly margined; surface with sparse, extremely fine punctures and extremely weak microreticulation; occipital line absent; eyes large; antennomeres I-II moderately elongate, III-XI short and broad. Pronotum broad, widest at posterior angles ( Fig. 4 ); lateral bead fine and continuous; surface shiny, covered with extremely fine punctures, slightly more coarse along anterior and lateral margins. Elytra short and broad, apices narrowly rounded ( Fig. 4 ); surface with sparse, fine punctures; sutural stria absent; elytral epipleuron without transverse carina at humeral angle. Prosternum medially tectiform and setose; prosternal process moderately broad, lateral margins parallel; margins carinate, medially longitudinally strongly canaliculate; apex rounded. Metasternum smooth, shiny, impunctate except on metasternal wings with few, indistinct punctures. Legs shiny, relatively impunctate; metatrochanter large, slightly offset from midline of metafemur ( Fig. 5 ); metacoxa shiny, with few, shallow punctures over surface. Abdomen shiny, with few punctures, mainly near sutures; apex of ventrite VI broadly pointed. Female genitalia: Gonocoxae elongate, apically elongate triangular, anteriorly with elongate apodemes ( Fig. 6 ); bursa moderately large, rounded; spermathecal duct extremely long, basally broad, narrowed thereafter and extremely long and narrow, expanded near receptacle; receptacle globular with small posterior, pointed lobe; spermatheca globular with prominent internal spermathecal spine; fertilization duct subtended by moderately large, broad flange, duct short and slender.

Variation. Specimens vary somewhat in the extent and degree of coloration on the elytron, with the maculae relatively expanded or reduced. The subbasal macula in some specimens has the medial portion slightly separated from the rest.

Etymology. The species is named puella, Latin for “girl,” after its evidently parthenogenetic reproductive strategy. The epithet is a noun in apposition.

Distribution and Habitat. The species is known from a single locality in Barinas State, Venezuela that is situated in the eastern foothills of the Cordillera de Mérdia, a northeastern extension of the Andes ( Fig. 7 ). The specimens were collected in a shallow pool of a small mountain stream that was formed where the stream crossed under a road ( Fig. 8B ).

Material Examined. Holotype in MIZA, male labeled, “ VENEZUELA: Barinas State 8°48.424′N, 70°31.139′W, 992m ca. 13km NW Barinitas ; 24.i.2012 leg. Short, Arias, & Gustafson Small stream pool; VZ12-0124-02B/ SEMC1029978 KUNHM-ENT [ SEMC barcode label]/ HOLOTYPE Belladessus puella Miller and Short, 2015 [red label with black line border].” Paratypes, 5 labeled same as holotype except “…/ PARATYPE Belladessus puella Miller and Short, 2015 [blue label with black line border]” and with SEMC numbers ( Table 1) .

Figures

Figs. 1–6. Belladessus species morphology. 1–3) B. femineus: 1) Habitus; 2) Left metacoxa, metatrochanter, and metafemur; 3) Female reproductive tract, ventral aspect. 4–6) B. puella: 4) Habitus; 5) Left metacoxa, metatrochanter, and metafemur; 6) Female reproductive tract, ventral aspect. Scale bar = 1 mm for Figs. 1 and 4.

Fig. 7. Distribution of Belladessus species.

Fig. 8. Habitats of Belladessus species. A) Type locality for B. femineus, collecting event SR13-0819-05B, on the summit of Tafelberg Tepui, Suriname, B) Type locality for B. puella, collecting event VZ12-0124-02B, ca. 13 NW Baranitas, Venezuela.