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

Figs 4 , 8 , 15 , 16 , 27-29 , 30

Type locality.

Ecuador, Pastaza, Puyo.

Diagnosis.

This species is shorter and more robust (Fig. 4 ) than either M. pulchellus or M. beni (Figs 1 , 3 ) although the dorsal color pattern is similar to them (Fig. 4 ). The male genitalia are diagnostic. The median lobe in M. rikae is trilobed like other Miradessus , but the median portion is uniquely short, broad, and apically broadly subtruncate with the ventral portions elongate, slender and apically narrowly rounded (Fig. 15 ).

Description.

Measurements. TL = 2.2 mm, GW = 1.2 mm, PW = 0.9 mm, HW = 0.6 mm, EW = 0.4 mm, TL/GW = 1.8, HW/EW = 1.5, FL/RL = 2.0.

Habitus. Body shape elongate-oval, lateral outline discontinuous between pronotum and elytron, posterior apex narrowly rounded (Fig. 4 ).

Coloration (Fig. 4 ). 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 orange; legs, epipleuron, and lateral areas of prothorax and head lighter orange-yellow.

Sculpture and structure. Head shiny and smooth, nearly impunctate, with small micropunctures sparsely distributed; eyes large (HW/EW = 1.5); antennae slender, unmodified. Pronotum with lateral margins moderately curved; with narrow bead along entire margin; surface shiny, moderately and evenly punctate; lateral pronotal plica distinctly impressed, sublinear, extending about 1/3 distance across pronotum. Elytron with lateral margin strongly curved anteriorly in dorsal aspect, evenly curved to apex; 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, laterally with prominent rounded ridges along entire length, medially longitudinally sulcate, lateral margins slightly convergent to narrowly rounded apex. Metaventrite and metaventral wings smooth and shiny, covered with shallow punctures (Fig. 8 ). 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 small, shallow punctures; metatrochanter about 1/3 length of metafemur (Fig. 8 ). Abdominal ventrites nearly impunctate except II and III laterally with shallow, indistinct punctures; VI with apex pointed.

Male genitalia. Median lobe in ventral aspect conspicuously trilobed, with medial portion short and broad, apically expanded and subtruncate, apicolateral angles with short setae, ventral portions elongate, slender, apically narrowly rounded (Fig. 15 ); lateral lobe in lateral aspect robust, basal segment somewhat broad and robust, apical segment broad basally, with deep emargination along dorsal margin, apex rounded with series of setae (Fig. 16 ).

Sexual dimorphism. Only males are known.

Variation. The two specimens exhibit slight variation in the shape and extent of maculation on the dorsal surface, but they are otherwise similar.

Etymology.

This species is named rikae after Ms Rikelle Timpe, close friend of the first author.

Distribution.

Miradessus rikae is known from two sites in Ecuador (Fig. 30 ).

Habitat.

The two known specimens were collected at blacklights, so nothing is known of the specific habitat. The two collection localities are in forested regions of lowland Ecuador.

Material examined.

Type material. Holotype male ( Figs 27-29 ) in USNM labeled, " ECUADOR,Past. Puyo. 1-7 Feb. 1976 at blacklight Spangler,et al./ ECUADOR-PEACE CORPS- SMITHSONIAN INSTITUTION AQUATIC INSECT SURVEY/ HOLOTYPE Miradessus rikae Miller, Benetti & Michat, 2023 [red label with double black line border]." One paratype male in USNM labeled " ECUADOR, NAPO, Lago Agrio(5 Km N) 26 Sept.1975 at blacklight Andrea Langley/ PARATYPE Miradessus rikae Miller, Benetti & Michat, 2023 [blue label with black line border]." Both the holotype and paratype have the male genitalia dissected and placed in microvials mounted on the pins.

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).