Miradessus pulchellus (Guignot, 1955) Miller & Benetti & Michat, 2023

Miller, Kelly B., Benetti, Cesar J. & Michat, Mariano C., 2023, Miradessus gen. nov. from South America described for two species previously in Amarodytes Regimbart, 1900 and two new species (Arthropoda, Insecta, Coleoptera, Adephaga, Dytiscidae, Hydroporinae, Bidessini), ZooKeys 1176, pp. 13-28 : 13

Miradessus pulchellus (Guignot, 1955) comb. nov.

Figs 3 , 7 , 13 , 14 , 17 , 24-26 , 30

Amarodytes pulchellus Guignot, 1955: 273; Young 1969: 2; Trémouilles 1995: 47; Nilsson and Hájek 2022: 101.

Type locality.

Colombia.

Diagnosis.

See above under the very similar M. beni for diagnosis.

Description.

Measurements. TL = 2.6-2.8 mm, GW = 1.3-1.4 mm, PW = 1.0-1.2 mm, HW = 0.6-0.8 mm, EW = 0.3-0.4 mm, TL/GW = 1.9-2.1, HW/EW = 1.7-1.8, FL/RL = 2.2-2.3.

Habitus. Body shape elongate-oval, lateral outline somewhat discontinuous between pronotum and elytron, posterior apex narrowly rounded (Fig. 3 ).

Coloration (Fig. 3 ). Head yellow-orange. Pronotum yellow-orange with a narrow, rounded lobe of black broadly along each side of posterior margin. Elytron maculate, yellow-orange and black, margins of maculae strongly demarcated; with large, transverse yellow-orange regions anteriorly, medially, and apically, not extending medially to suture, with narrow band of black along entire length of suture, margins of maculae irregular and variously lobed. Ventral surfaces mostly dark orange-brown, legs, epipleuron, and ventral areas of prothorax and head lighter orange-yellow, some sutural margins darker, infuscate, mesothoracic ventrites and prosternal process strongly infuscate to nearly black.

Sculpture and structure. Head shiny and smooth, nearly impunctate, with small micropunctures sparsely distributed; eyes large (HW/EW = 1.7-1.8); antennae slender, unmodified. Pronotum with lateral margins moderately curved anteriorly, shallowly curved posteriorly; with narrow bead along entire margin; surface shiny, moderately and evenly punctate; lateral pronotal plica weakly impressed, sublinear, extending about 1/3 distance across pronotum. Elytron with lateral margin evenly and broadly rounded; surface shiny, moderately, and evenly punctate. Prosternum medially moderately broad, medially not protruberant, mediolaterally somewhat granular; prosternal process moderately broad medially with slight tubercle, apical blade large, with fine setae, laterally with low rounded ridges along entire length, medially longitudinally shallowly sulcate, lateral margins slightly convergent to narrowly rounded apex (Fig. 7 ). Metaventrite and metaventral wings smooth and shiny, covered with shallow punctures. Metacoxa with medial portion moderately broad, metacoxal lines distinct, evenly divergent anteriorly to posterior margin of metaventrite; lateral portion large, medially and anteriorly covered with shallow punctures; metatrochanter about 1/3 length of metafemur (Fig. 7 ). Abdominal ventrites impunctate except II and III laterally with shallow, indistinct punctures; VI strongly concave in lateral aspect, apex pointed.

Male genitalia. Median lobe in ventral aspect broad, trilobed, with medial, dorsal elongate slender, apically pointed portion and ventral, elongate apically bilobed portion, with each ramus elongate and apically truncate, medial dorsal portion nearly as long as ventral portions (Fig. 13 ); lateral lobe in lateral aspect robust, basal segment moderately broad, curved, apical segment elongate, slightly curved ventrad, apex rounded (Fig. 14 ).

Female genitalia (Fig. 17 ). Bursa copulatrix short; spermathecal duct extremely long, slender, somewhat coiled, broadly expanded in elongate section before receptacle; receptacle similar in size to spermatheca, intermediate duct between receptacle and spermatheca broad, short; spermatheca spherical with broad, somewhat more sclerotized expansion at opening to spermathecal duct, spermathecal spine prominent, elongate, and broad; fertilization duct slender, irregularly curved, heavily sclerotized.

Sexual dimorphism. Males have the pro- and mesotarsomeres I-III slightly but distinctly broader than in females. Abdominal ventrite VI strongly concave in lateral aspect in females, but medially somewhat swollen and apically with a broadly rounded depression in males.

Variation. There is some minor variation in extent of coloration of the dorsal surface, but otherwise specimens are similar.

Distribution.

Miradessus pulchellus was described from Colombia, without greater specificity. Specimens were examined from numerous localities throughout northwestern Venezuela (states of Barinas, Guarico, Lara, Portuguesa, Tachira, Trujillo, and Zulia) (Fig. 30 ).

Habitat.

Specimens have been collected mainly from exposed and sunny areas in lotic margins (small rivers and streams) and nearby pools. They are often numerous in these habitats.

Material examined.

Type specimens. Holotype male (Figs 24-26 ) in ZSMG labeled, "pulchellus in Colomb [HW]/ Sammlung C.L. Müller / Amarodytes nov. speci. [handwritten]/ Type [red label]/ Holotypus [red label]/ Dr. F. Guignot det., 1955 Amarodytes pulchellus n. sp. Type. [handwritten]." The holotype has the male genitalia and apical abdominal segments dissected. No other type specimens accompany the holotype in ZSMG (D.A. Balke pers. comm.).

Other material examined. 134 total examined, all from Venezuela (SEMC), with the following data (SEMC accession numbers in Table 1 ); 7, Barinas, Rio Caramuca , E of El Corozo, 8°35.449'N, 70°19.427'W, 213 m, 14 Jul 2009, Short et al., river margins, VZ09-0714-04A; 1 , Barinas, Rio Paguey at Los Rozos , 8°30.764'N, 70°27.233'W, 190 m, 24 Jan 2012, Short, Arias and Gustafson, river margins, VZ12-0214-03A; 7 , Barinas, Rio Sta Barbara , E Sta Barbara, 7°50.028'N, 71°11.188'W, 177 m, 26 Jan 2012, Short, Arias and Gustafson, sandy sidepool in floodplain, VZ12-0126-01B; 6 , Barinas, river nr Bum Bum , 8°18.033'N, 70°45.201'W, 216 m, 15 Jul 2009, Short et al., river margins, VZ09-0715-02A; 40 , Guarico, Rio San Antonio , N Dos Caminos, 9°46.320'N, 67°21.177'W, 280 m, 8 Jan 2009, Miller and Short, side stream, VZ09-0108-02B; 6 , Guarico, Rio San Antonio , N Dos Caminos, 9°46.320'N, 67°21.177'W, 280 m, 8 Jan 2009, Short, Miller, García, Camacho and Joly, river margin, VZ09-0108-02A; 4 , Guarico, Rio San Antonio , N Dos Caminos, 9°46.320'N, 67°21.177'W, 280 m, 8 Jan 2009, Short, Miller and García, river margin, VZ09-0108-02A; 39 , Lara, Rio Salado , W of Arenales, 10.15433333°N, 69.95763333°W, 490 m, 22 Jan 2009, Short, Camacho, Garcia, gravel stream, VZ09-0122-01X; 1 , Portuguesa, Rio Are at Aparición, 9°22.900'N 69°23.153'W, 220 m, 22 Jan 2012, Short, Arias, river margins, VZ12-0122-02A; 3 , Portuguesa, Aparición by highway, 9°22.268'N, 69°23.062'W, 213 m, 22 Jan 2012, Short, Arias & Gustafson, roadside pond, VZ12-0122-01A; 10, Trachira, El Tama National Park , 7°35.038'N, 72°10.340'W, 472 m, 16 Jul 2009, Short, Sites, García, Inciarte, Gustafson and Camacho, HG Vapor light, VZ09-0716-07A; 3 , Trujillo, Rio Jiripara nr. Sabana Grande , 9°42.307'N, 70°32.570'W, 199 m, 29 Jan 2012, Short, river margins, VZ12-0129-02B; 6 , Trujillo, Rio Jiripara nr Saban Grande , 9°42.307'N, 70°32.570'W, 199 m, 29 Jan 2012, Short, Arias and Gustafson, muddy pool in floodplain, VZ12-0129-02A; 1 , Zulia, Perija NP, Tukuko, Rio Tukuko , 9°50.513'N, 72°48.334'W, 252 m, 5 Jul 2009, Short and Gustafson, riffle/rocks in river, VZ09-0705-01B .

Figures

Figure 30. Miradessus species, distributions.

Figures 1 - 8. Miradessus species 1 - 4 dorsal habitus 1 M. beni 2 M. plaumanni 3 M. pulchellus 4 M. rikae 5 - 8 prosternal process left surfaces of metaventrite metacoxa metatrochanter and metafemur 5 Miradessus beni 6 M. plaumanni 7 M. pulchellus 8 M. rikae. Scale bars: 1.0 mm (1 - 4); 0.5 mm (5 - 8).

Figures 9 - 17. Miradessus species 9, 10 M. beni, male aedeagus 9 median lobe and left lateral lobe, dorsal aspect 10 right lateral lobe, right lateral aspect 11, 12 M. plaumanni, male aedeagus 11 median lobe and lateral lobes, dorsal aspect 12 right lateral lobe, right lateral aspect 13, 14 M. pulchellus, male aedeagus 13 median lobe and left lateral lobe, dorsal aspect 14 right lateral lobe, right lateral aspect 15, 16 M. rikae, male aedeagus 15 median lobe and lateral lobes, dorsal aspect 16 median lobe and right lateral lobe, right lateral aspect 17 M. pulchellus, female genitalia, ventral aspect. Scale bar: 0.25 mm.

Figures 18 - 29. Miradessus species, primary type specimens and labels 18 - 20 M. beni, holotype specimen 18 dorsal habitus 19 ventral habitus 20 specimen labels 21 - 23 M. plaumanni, lectotype specimen 21 dorsal habitus 22 ventral habitus 23 specimen labels 24 - 26 M. pulchellus, holotype specimen 24 dorsal habitus 25 ventral habitus 26 specimen labels 27 - 29 M. rikae, holotype specimen 27 dorsal habitus 28 ventral habitus 29 specimen labels. 21 - 23 courtesy of M. Schwarz (OLML) 24 - 26 courtesy of M. A. Balke (ZSMG).