Miradessus beni 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 beni Miller, Benetti & Michat sp. nov.

Figs 1 , 5 , 9 , 10 , 18-20 , 30

Type locality.

Bolivia, Departmento de La Paz, Provincia de Abel Iturralde, San Miguel del Bala, 14°30.602'S, 67°29.555'W.

Diagnosis.

This species and M. pulchellus are extremely similar externally, with similar overall shape, color pattern, and other features (Figs 1 , 3 ). The external differences between them are subtle, including the shape of the prosternal process, which is more prominently laterally carinate and deeply sulcate in M. pulchellus than in M. beni . Also, the ventral surface is darker in most specimens of M. pulchellus than in M. beni . The main differences between these species are in the male genitalia, which are distinctive and characteristic. Both have the median lobe trilobed (with two side portions and a middle portion), but in M. pulchellus the middle portion is nearly as long as the side portions and the apex has a distinct, fine pencil of setae on each side that are divergent (Fig. 13 ). In M. beni the middle portion is considerably shorter than the side portions and has a series of setae along its apex (Fig. 9 ). In lateral aspect, the lateral lobe of M. pulchellus has the apical segment nearly as long as the basal segment and it is curved ventrad (Fig. 14 ). In M. beni the lateral lobe has the apical segment only about 1/3 the length of the basal segment and it is curved dorsad (Fig. 10 ).

Description.

Measurements. TL = 2.7-2.8 mm, GW = 1.3-1.4 mm, PW = 1.0-1.1 mm, HW = 0.7-0.8 mm, EW = 0.3-0.4 mm, TL/GW = 2.0-2.1, HW/EW = 1.8-1.9, FL/RL = 2.2-2.3.

Habitus. Body shape elongate-oval, lateral outline somewhat discontinuous between pronotum and elytron, posterior apex narrowly rounded (Fig. 1 ).

Coloration (Fig. 1 ). 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 (Fig. 1 ). Ventral surfaces mostly orange; legs, epipleuron, and lateral 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 moderately large (HW/EW = 1.8-1.9); 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, covered with fine setae, laterally with prominent rounded ridges along entire length, medially longitudinally sulcate, lateral margins slightly convergent to narrowly rounded apex (Fig. 5 ). Metaventer and metaventral wings smooth and shiny, covered with shallow punctures (Fig. 5 ). 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. 5 ). 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 dorso-medial, elongate, slender, apically pointed ramus and another ventral, elongate, apically bilobedramus, with each ramus elongate and slender, medial dorsal ramus much shorter than ventral ramus (Fig. 9 ); lateral lobe in lateral aspect robust, basal segment very broad, robust, apical segment short, robust, curved dorsad, apex obliquely truncate (Fig. 10 ).

Sexual dimorphism. Males have the pro- and mesotarsomeres I-III slightly but distinctly broader than in females. Abdominal ventrite VI distinctly concave in lateral aspect in females, but medially more expanded and apically somewhat depressed in males.

Variation. There is some minor variation in shape and extent of coloration of the dorsal and ventral surfaces but otherwise specimens are similar.

Etymology.

This species is named beni after the name Río Beni, the river at the type locality of the species. The name is a noun in apposition.

Distribution.

Miradessus beni is known from the type locality in lowland Departmento de La Paz, Bolivia and from two sites in lowland Peru (Fig. 30 ).

Habitat.

The type locality is a heavily forested area of the Andean foothills next to a large river. However, nothing is known of the specific collection habitat of this species.

Material examined.

Type material. Holotype ( Figs 18-20 ) in MIZA, male labeled, " BOLIVIA: La Paz Dept. Ituralde [sic] Prov., San Miguel 14°30.602'S, 67°29.555'W, 24-30 Sept. 2007 KB Miller KBMC24090701/ HOLOTYPE Miradessus beni Miller, Benetti & Michat, 2023 [red label with black line border]."

Paratypes, 41 total; 6 paratypes (MIZA, MSBA) labeled same as holotype;" 8 paratypes (USNM) labeled, " PERU:Dpt. Cuzco Prov. Quispicanchis Quincemil 6-II-X-1976 Robert Gordon" ; 12 paratypes (ZSMG) labeled, " Bidessus cruciatus? [handwritten] / Amarodytes pulchellus [handwritten] / Peru, Prov. Huanuco, Rio Yuyapichis, Biol. Stat. Panguana. Oestl . Ort. 9°37'S, 74°56'W 6.-17.April 2003, Malaise [handwritten], leg. H., J. u. E. -G. Burmeister " ; 2 paratypes (ZSMG) labeled, " PERU, Dept. Huanuco, Panguana ACP, Rio Yuyapichis 9°37'S - 74°56'W, at blacklight, XII.2015 J. Monzon leg." ; 4 paratypes (ZSMG) same as previous except “… / 230 m, blacklight trap / Hydrodessus sp. 1 [handwritten], Hendrich dt. 2020" ; 3 paratypes (ZSMG) same as previous except “…/I.2016”; 4 paratypes (ZSMG) same as previous except “… /V-VI.2017/ Dytiscidae ? Hydrodessus sp. [handwritten], H.J. Bremer det. 2018" ; 2 paratypes (ZSMG) same as previous except “… / Lux - 20.9.- 9.10.2007 leg. Burmeister. " Each paratype with “… / PARATYPE Miradessus beni Miller, Benetti & Michat, 2023 [blue label with black line border]."

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).