Ambrysus xico Reynoso, Sites

Reynoso-Velasco, Daniel, Sites, Robert W. & Novelo-Gutiérrez, Rodolfo, 2016, The Ambrysus Stål (Heteroptera: Naucoridae: Cryphocricinae) of Mexico: Revision of the subgenus Syncollus La Rivers, Zootaxa 4126 (1) : -

Ambrysus xico Reynoso, Sites , & Novelo NEW SPECIES

( Figs. 4 , 12–13 )

Description. Brachypterous male. HOLOTYPE, length 7.92; maximum width 4.76. Paratypes (n = 2), length 7.92; maximum width 4.32–4.48 (mean = 4.40). General shape elongate, parallel-sided; widest across embolia ( Fig. 12 A). Dorsal coloration of head, pronotum, and hemelytra dark brown; legs yellowish brown. Dorsal surface coarsely punctate and tuberculate. Ventral coloration of head and thorax medium brown, abdomen with dense golden brown pubescence.

Head. Head length 1.56; maximum width 1.96. Mostly dark brown with yellowish brown stripe on midline posteriorly and on either side of midline between eyes, coarsely punctate and tuberculate. Eyes convergent anteriorly, synthlipsis 1.08; thin band of cuticle along posterolateral margin of eye; eyes not raised above level of vertex or pronotum. Anterior margin between eyes slightly convex, extending anteriorly in front of eyes 10% of head length; posterior margin between eyes strongly convex, extending posteriorly 41% of head length. Labrum width 1.9× length, evenly rounded. Labium with three visible yellowish brown segments, darkening distally, extending 0.44 beyond labrum not including extruded stylets. Antennal proportions 3:7:10:7, length 0.54, extending to near lateral margin of eye, elongate hairs on segment 4 and distal half of 3.

Thorax. Pronotum coarsely punctate and tuberculate, ground color yellowish brown; transverse sulcus marking anterior border of transverse band in posterior 1/4; transverse band pale yellow with color extending anteriorly on midline as elongate, pointed marking; ovoid dark brown mark on either side of midline at anterior margin; dark, broad, submarginal band extending from eye to transverse band, reaching lateral margin; lateral margins dark brown, convergent, evenly convex, explanate; posterior margin straight; anterior margin deeply concave between eyes to embrace convex posterior margin of head; posterolateral corners rounded; width 2.8× length; length at midline 1.36; maximum width at posterolateral corners 3.92. Prothorax ventrally pruinose throughout; apices of propleura meeting at midline, closely appressed to prosternellum; propleuron brown throughout, medial 2/3 of posterior margin with elongate golden setae. Probasisternum with sharp median carina, with row of short setae lateral to carina. Prosternellum covered by apices of propleura. Scutellum coarsely punctate and tuberculate, triangular, entirely brown with light brown on corners, width 2.0× length, width 2.48, length 1.22. Hemelytra densely punctate and tuberculate, dark brown, surpassing apex of tergum V, length 5.44 (chord measurement). Clavus with thin, yellow transverse stripe at base, length 4.8× width, length 2.88, width 0.60; claval commissure yellowish brown, length 0.98. Embolium length 2.36, greatest width 0.62; lateral margin convex, light brown in anterior 2/3, becoming darker posteriorly. Oblique suture connecting claval and embolar sutures near bases. Hind wings extending to anterior 1/4 of tergum V. Mesobasisternum midventral tumescence negligible, with sulcus on midline continuing through triangular mesosternellum. Metasternellum (= metaxyphus) transverse, subtriangular, with median carina, apex acute.

Legs. All legs segments brown to yellowish brown. Profemur brown; posterior margin with row of tightly arranged setae in basal 2/3, row of short brown spines along middle third, spines generally single proximally becoming small combs of two to five spines distally; anterior margin with dense pad of setae without associated spines. Protibia and tarsus with occlusal inner surface flattened and with spatulate setae; tarsus immovable, onesegmented; pretarsal claw single, minute, triangular. Procoxa with cluster of stout, brown anteromedial spines. Meso- and metacoxae partially recessed into thorax. Meso- and metafemora with row of short, brown spines on anterior margin; spines restricted to basal half on mesofemur, nearly full length of metafemur. Mesotibia with ventrolateral, ventromedial, dorsolateral, and dorsomedial rows of stout reddish-brown spines; ventromedial rows intermixed with combs of two to five spines. Metatibia with ventrolateral, dorsolateral, and dorsomedial rows of stout reddish-brown spines. Meso- and metatibia with semi-circlet of spines at apex of dorsal and mesal margins; two comb rows of stout spines near apex of ventral margin, lateral margin without spines at apex to accommodate flexed tarsus. Meso- and metatibiae and metatarsi with long, pale swimming hairs; hairs profuse on metatibia and - tarsus. Meso- and metapretarsi with paired claws slender, gently curved, with small basal tooth. Leg measurements as follows: foreleg, femur 2.12, tibia 1.94, tarsus 0.40; middle leg, femur 2.2, tibia 1.96, tarsomeres 1–3, 0.18, 0.34, 0.44; hind leg, femur 2.56, tibia 2.84, tarsomeres 1–3, 0.20, 0.50, 0.56.

Abdomen. Dorsally with connexiva III–VIII exposed, each laterotergite dark brown in posterior half and light brown in anterior half giving checkered appearance ( Fig. 12 A); lateral margin finely serrate, marginal row of short yellow setae, group of trichobothria near posterolateral corners. Posterolateral corners of II (visible ventrally) –IV narrowly rounded to right angled and not spinose, V obtuse and not spinose, VI–VII bluntly acute. Accessory genitalic process of tergum VI short, curved to right at approximately 45 degrees, acuminate distally ( Fig. 12 B). Medial lobes of tergum VIII (pseudoparameres) long, semirounded, asymmetrical, with left pseudoparamere slightly narrower ( Fig. 12 C). Ventrally entirely golden brown, with dense pile of fine hairs. Lateral margin with thin, glabrous band. Glabrous rounded to oval patches around spiracles on laterosternites II–VII. Phallosoma elongate, linear, constricted basally, sclerotized dorsally; right and left ventral lobes of endosoma papillose, left ventral lobe lightly sclerotized ( Fig. 12 E). Parameres symmetrical, almost as long as wide, mesal margin straight, narrowly rounded anteriorly, long setae on posterior half. Proctiger short, length 0.6× width. Pygophore with elongate setae sparsely distributed over most of surface, with thick brush of elongate setae on posterior margin ( Fig. 12 D).

Brachypterous female. Paratypes (n = 3), length 8.48–9.28 (mean = 8.80); maximum width 4.88–5.20 (mean = 4.99). Similar to male in general structure and coloration except as follows: hemelytra surpassing posterior margin of tergum VI. Mediosternite VII (subgenital plate) width 1.4× length; length at midline 0.88; maximum width 1.30; with deep medial concavity twice as wide as long; posterolateral corners narrowly rounded ( Fig. 12 F).

Macropterous male. Unknown.

Macropterous female. Unknown.

Variation. The small number of specimens (3♂, 3♀) did not allow us to assess variation of the diagnostic features.

Diagnosis. Ambrysus xico presents distinct, minute, individualized small tubercles on the head, prothorax, scutellum, and hemelytra not connected by ridges. The other species revised in this study present these tubercles interconnected by sclerotized ridges, resulting in a polygonal pattern. This species has darker coloration when compared with the other Mexican species of Syncollus. The dark brown submarginal band on the prothorax is wider and reaches the lateral margin anteriorly. The posterolateral corners of tergum V are not acutely angled as in the other the species, but are rounded and obtuse. The pseudoparameres are asymmetrical with the left pseudoparamere slightly longer and narrower. These pseudoparameres are similar to those of A. circumcinctus , although not as constrained medially. The female subgenital plate has a concavity that is exactly twice as wide as long and is similar to that of A. baeus , although the posterolateral corners of the latter species are narrower.

Habitat description. The stream at the type locality ( Fig. 13 ) is part of the Río La Antigua basin in the central area of Veracruz state. The stream originates on the eastern slopes of the Cofre de Perote volcano at the eastern limit of the Transmexican Volcanic Belt. This mountain stream is approximately 5 meters wide and has areas with strong current and riffles. Most of our collecting was conducted in those areas, and although species in this subgenus prefer habitats with strong current, A. xico was not commonly collected; thus this species might have other habitat preferences.

Distribution. This species was collected in Veracruz from three mountainous streams above 1400 meters elevation in the Río La Antigua Basin in the central part of the state, the transition zone between the Transmexican Volcanic Belt and the Sierra Madre Oriental biogeographic provinces. In the state of Querétaro, A. xico was collected in a small stream at 2000 meters elevation. Our extensive collecting suggests that A. xico could be endemic to streams at high elevation in the Transmexican Volcanic Belt biogeographic province ( Fig. 4 ). We found A. xico and A. totonacus n. sp. syntopically at L- 1557 in the state of Veracruz.

Etymology. The specific epithet is a noun in apposition and refers to the municipality of Xico , in the central part of Veracruz, where most of the specimens were collected.

Repositories. The holotype and one female paratype will be deposited in the Colección Nacional de Insectos ( Mexico City); additional paratypes are deposited in the Enns Entomology Museum (University of Missouri) and the Essig Museum of Entomology Collection (Berkeley).

Type material examined. HOLOTYPE ♂: MÉXICO: VERACRUZ: Mpio. San Andrés Tlalnehuayocan, 1.16 km NW of Tres Marias, 19º 30' 55.6'' N, 97º 00' 27.4'' W, 15 June 2013, L-1556 / 1602 m, [Arroyo Piedra Blanca] rocky mountain stream, Reynoso-Velasco, Sites, Shepard, Novelo & Reynoso-Hernández, colls. PARATYPES: QUERÉTARO: Mpio. Amealco, Puerta de Alegrías, Arroyo las Zúñigas, 8-VII-2000, C. B. Barr / S of Galindo, 20º 20' 28'' N, 100º 07' 10'' W, elev. 2000 m (1♀ EMEC). VERACRUZ: Mpio. Xico , Arroyo Avestruces, vegetated margin of rocky stream in cattle pasture, 16 June 2013, L-1557 / 1401 m, 19º 23' 53.8'' N, 97º 02' 29.9'' W, Sites, Shepard, Novelo, Reynoso-Hernández & Reynoso-Velasco, colls. (1³ UMC); same locality information but rootmats, 29 May 2014, L-1799, DRV & PRH (1³ UMC); Mpio. Xico , Xico Viejo, 19º 27' 14.10'' N, 97º 03' 31.5'' W, 1780 m, 30-Ago-1997, R. Arce col. (1♀ CNIN; 1♀ UMC).

Figures

FIGURE 4. Distribution of Ambrysus baeus, A. chiapanecus n. sp., A. totonacus n. sp., A. pygmaeus, and A. xico n. sp. in Mexico (topographic map modified from Mexico map relief by Carport and used under CC BY 3.0).

FIGURE 12. Structures of Ambrysus xico n. sp. (A) dorsal habitus of holotype, (B) 6 th and 7 th abdominal terga of male, (C) 8 th abdominal tergum of male, (D) genital capsule of male (phallosoma removed), (E) ventral side of phallosoma, (F) 6 th abdominal sternum and subgenital plate of female (terminal segments removed). Size bar = 0.5 mm and applies only to Figs. D and E.

FIGURE 13. Type locality of Ambrysus xico n. sp. at Arroyo Piedra Blanca (Veracruz, México).