Amazonopsis camachoi, Barr, Cheryl B., 2018

Barr, Cheryl B., 2018, Amazonopsis, an unusual new genus of riffle beetle from South America with two new species (Coleoptera, Elmidae, Elminae), ZooKeys 803, pp. 71-92 : 84-88

Amazonopsis camachoi sp. n. Figs 9, 10

Type material.

Holotype male deposited in MALUZ, labeled: "VENEZUELA, Bolívar / Muncipio Gran Sabana / El Paují. 25/IV/2004 al / 02/V/2004 J. Camacho, / J. Perozo, Col. // 04°28'06" N / 61°35'38" W / 880msnm // MALUZ 10031 / LUZ-Venezuela // HOLOTYPE / Amazonopsis / camachoi Barr" [red label, handwritten].

Diagnosis.

Amazonopsis camachoi males (Figs 9, 10) differ from those of A. theranyi (in parentheses) (Figs 1, 2, 4, 5) by the following characters: elytra with pronounced protuberances at humeral angles (low protuberances), third elytral interval prominently raised (slightly raised), odd-numbered intervals with longitudinal rows of thick setae (all intervals with fine, sparse setae); protarsomere 5 with two apical clusters of long, curved setae extending well beyond base of claws (sparse setae barely extending to base of claws); protarsal claws short, strongly curved (elongate, moderately curved), outer claw with inner tooth (without inner tooth), outer claw width narrower than that of inner claw (width similar); outer mesotarsal claw as long as tarsomere 5 (shorter than tarsomere 5) and at least 3 × wider than inner claw (2 × wider); distance between prosternal spines as wide as labrum (distance narrower); metaventrite with pair of prominent lobe-like processes (processes less prominent, tooth-like); male genitalia with parameres very narrow and straight (wider and sinuate), penis much wider at base than paramere base (width subequal), phallobase longer than parameres (length subequal).

Description.

Holotype male (Figs 9, 10). Length, 4.70 mm; width, 2.00 mm. Cuticle mostly covered with pale, thin microreticulate layer dorsally and ventrally, with thicker, pale yellow plastron ventrolaterally on thoracic sterna and abdominal ventrites; cuticle shiny, dark reddish-brown where exposed. Antenna. Yellow-brown. Antennomeres 1-10 clavate, antennomere 11 fusiform; antennomeres 1 and 2 each stouter than 3-10 which are of similar size and shape; antennomeres 3-10 each with dense tuft of setae at apicoventral margin, overlapping base of next; antennomere 11 with a faintly visible, elongated patch of short setae near the ventral apex. Head. Vertex, frons and clypeus covered with pale, microreticulate plastron and broad, flat, yellow setae. Clypeus dark brown, barely emarginate at center of apical margin, setae slightly less dense than on vertex and frons. Labrum red-brown, barely emarginate, apicolateral angles broadly rounded; surface with small, evenly spaced punctures and short, fine setae; apical and lateral margins with fringe of pale, dense setae, longest laterally. Mandible with three short, rounded, apical teeth. Maxillary palpus yellow-brown; palpomere 4 slightly flattened and curved, longer than 1-3 combined, with oval patch of sensillae at apex. Labial palpus with palpomeres 1 and 2 short, yellow-brown; palpomere 3 longer than 1 and 2 combined, yellow-brown, ovoid and moderately flattened. Pronotum. Length, 1.40 mm; width, 1.60 mm. In dorsal view, lateral margins coarsely granulate, evenly arcuate; anterior margin trisinuate, emarginate at middle; anterolateral angles acute, depressed. In lateral view, disc slightly flattened at anterior ⅔. Disc covered with pale microreticulate plastron and closely spaced, coarse punctures; punctures larger and deeper near lateral and apicolateral margins, smaller and shallower, often indistinct, over much of central disc; punctures generally spaced a diameter apart; punctures lined with plastron and associated with very short, erect setae; anteromedial disc and lateral areas with broad, flat, recumbent, yellow setae. Center of midline with narrow, slightly impressed, mostly bare, longitudinal line; length about ¾ that of pronotum. Scutellum slightly ovate. Elytron. Length, 3.30 mm; width, 1.00 mm. Surface covered with pale, thin microreticulate plastron; punctures striate, deep, coarse, lined with plastron; strial intervals 1, 3, 5, 7, 9 each with partial, longitudinal rows of broad, flat, recumbent, yellow setae (originally complete rows, now partly abraded). Humeral angle with prominent, knob-like, posteriorly directed protuberance; base of third interval conspicuously swollen and raised; lateral margins smooth, recurved with narrow, longitudinal band of hypomeron plastron visible; shallow sulcus about one interval wide adjacent to lateral margin, extending from humeral angle to apical 1/5; elytra constricted at apical 1/5 at point of linkage with abdominal ventrite 4 lateral lobe; apex evenly rounded, moderately produced. Legs. Femora and tibiae covered by thin layer of dense plastron, sparsely setose and shallowly punctate; tarsus red-brown, without plastron. Procoxa posterior surface coarsely punctate. Prothoracic leg with tibia longer than femur, tarsus shorter (note: description is of right protarsus; left is missing); profemur with oval patch of long, recumbent pale yellow setae on anterior surface near base; protibia with pair of cleaning fringes, anterior fringe nearly ½ tibial length, posterior fringe about 1/4 tibial length; protarsus with tarsomeres 1-4 bearing tufts of long, curved setae in two rows at apicoventral margins; tarsomere 5 longer than the others combined, with moderately long setae on ventral surface and two apical clusters of long, curved, golden-yellow setae which extend well past base of claws. Protarsal claws short, stout, slightly twisted, laterally flattened, dissimilarly shaped; inner claw slightly bent at base, distal ½ widened, tip broadly acute and bent ventrally; outer claw not bent at base, inner tooth present about ⅓ distance from base, distal ½ narrowed, apex narrowly acute. Mesocoxa coarsely punctate and granulate; dense patch of long, pale yellow setae present on lateral face and adjacent sternum. Mesothoracic leg similar to prothoracic leg except mesofemur with patch of long, recumbent setae on basal ⅓ of posterior surface; mesotibial cleaning fringes ⅔ as long as tibia; tarsomere 5 with long, sparse, apical setae. Mesotarsal claws dissimilarly shaped, much longer than protarsal claws, laterally flattened, sharply acute; outer claw enlarged, as long as tarsomere 5, curved outward, bent more than 90° at base then flattened and widened, at least 3 × wider than inner claw; inner claw much shorter, straighter and narrower. Metacoxa medial surface with band of coarse, deep punctures; posterolateral surface with dense patch of long, golden-yellow setae. Metathoracic leg similar to other legs except tibia much longer than femur; single cleaning fringe on posterior face about ⅔ as long as tibia; tarsomere 5 with long, sparse, apical setae; both claws slightly flattened but basically unmodified, stout, shorter than pro- and mesotarsal claws. Venter. Hypomeron with large, coarse, closely spaced punctures, more than 2 × diameter of lateral pronotal punctures; ventral margin with broadly rounded lobe directed toward coxa; narrow, longitudinal band of pale yellow plastron present on ventral margin. Prosternum anterior margin prominently raised, bearing two small, ventrally directed spines; distance between spines as wide as labrum; anterolateral margin behind each eye having a small, nearly semicircular notch with dorsal margin hook-shaped; prosternal process about 2 × as long as wide, with elevated margin; prosternal disc covered with large, irregular punctures and microreticulate plastron, lateral margins with dense plastron. Mesoventrite depressed between mesocoxae; punctation similar to that of prosternum; disc with pale, microreticulate plastron, mesepimeron with band of more dense, pale yellow plastron. Metaventrite depressed between mesocoxae; discrimen sulcate; left posteromedial margin with a prominent, ventrally directed, lobe-like process (right process was destroyed by insect pin); punctures circular and mostly spaced less than a diameter apart; disc with pale plastron except along midline, most dense laterad and on metepisternum. Abdomen with pale yellow plastron on all surfaces except for areas of bare, shiny cuticle at midline; ventrites 1-4 mostly without setae, ventrite 5 with fine, scattered setae; punctures large, becoming progressively smaller with each succeeding ventrite; punctures evenly spaced but less dense than on thoracic sternites; ventrite 1 anterior margin between metacoxae sinuate with two shallow sinuses; ventrite 5 with two basolateral swellings each bordered by a shallow depression, apical ⅓ slightly depressed and margin broadly rounded. Abdomen is separated from rest of body and mounted on a card point. Genitalia (Fig. 10). Elongate, narrow. Phallobase longer than parameres, narrowest at basal ⅓. Paramere in dorsal and ventral views (Fig. 10a, c) straight, very narrow, narrowest ½ distance from base; apex narrowly rounded, clasping tip of penis; paramere in lateral view (Fig. 10b) with dorsal margin narrowed at midpoint, apex broadly rounded; inner surface shallowly canaliculate. Penis shorter than parameres; base much wider than paramere base; apical ½ narrow, narrowest point ¾ distance from base; apex narrowly rounded; corona and fibula absent; basal apophyses about ⅓ as long as phallobase.

Etymology.

Named for Jesús Camacho of La Universidad del Zulia, Maracaibo, Venezuela, who collected the unique type specimen.

Distribution.

This species is currently known only from one locality in southeastern Venezuela (Fig. 6).

Habitat.

The collector of the specimen recalled that the stream was small, shallow, sandy, and shaded, and that its waters were dark, tannin-stained, and contained decaying leaves (Camacho, in litt.).

Associated taxa.

The only other specimen known from this locality, an unidentified species of Heterelmis ( Elmidae ), is in the MALUZ collection (Camacho, in litt.).