Ambrysus chiapanecus 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 chiapanecus Reynoso, Sites , & Novelo NEW SPECIES

( Figs. 4–6 )

Description. Brachypterous male. HOLOTYPE, length 7.36; maximum width 4.40. Paratypes (n = 7), length 7.12–7.76 (mean = 7.37); maximum width 4.16–4.56 (mean = 4.29). General shape elongate, parallel-sided; widest across embolia ( Fig. 5 A). Dorsal coloration of hemelytra brown, with light brown along midline and posterior and lateral margins of corium; head, pronotum, and legs yellowish brown. Dorsal surface coarsely punctate. Ventral coloration of head and thorax yellowish brown, abdomen with dense golden brown pubescence.

Head. Head length 1.44; maximum width 2.04. Mostly yellowish brown with medium brown posteriorly, coarsely punctate. Eyes convergent anteriorly, synthlipsis 0.96; 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 11% of head length; posterior margin between eyes strongly convex, extending posteriorly 39% of head length. Labrum width 1.7× length, evenly rounded. Labium with three visible yellowish brown segments, darkening distally, extending 0.34 beyond labrum not including extruded stylets. Antennal proportions 2:6:7:7, length 0.48, extending to near lateral margin of eye, elongate hairs on segment 4 and distal half of 3.

Thorax. Pronotum coarsely punctate, ground color yellowish brown; transverse sulcus marking anterior border of transverse band in posterior 1/4; transverse band pale yellow; ovoid light brown mark on either side of midline at anterior margin; dark submarginal band extending from eye to transverse band; 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 2.9× length; length at midline 1.24; maximum width at posterolateral corners 3.60. Prothorax ventrally pruinose throughout; apices of propleura meeting at midline, closely appressed to prosternellum; propleuron yellowish throughout, medial 1/3 of posterior margin with elongate golden setae. Probasisternum with sharp median carina and without row of setae lateral to carina. Prosternellum covered by apices of propleura. Scutellum coarsely punctate, triangular, brown, light brown coloration along margins and midline, width 2.0× length, width 2.52, length 1.26. Hemelytra dark brown, densely punctate, not reaching apex of tergum V, length 5.12 (chord measurement); corium with light brown narrow oblique line at middle and posterior and lateral margins. Clavus with thin yellow stripe at base and apex, length 4.3× width, length 2.80, width 0.64; claval commissure brown, length 0.80. Embolium length 2.20, greatest width 0.54; lateral margin convex, yellow brown in anterior 2/3, becoming darker posteriorly. Oblique suture connecting claval and embolar sutures near bases. Hind wings extending to posterior margin of tergum III. 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 yellowish brown. Profemur 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 four 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, one-segmented; 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 metatibiae 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 metatarsus 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 2.08, tibia 1.72, tarsus 0.40; middle leg, femur 2.04, tibia 1.88, tarsomeres 1–3, 0.16, 0.34, 0.44; hind leg, femur 2.48, tibia 2.84, tarsomeres 1–3, 0.24, 0.46, 0.56.

Abdomen. Dorsally with connexiva III–VIII exposed, laterotergites light brown ( Fig. 5 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–VII bluntly acute. Accessory genitalic process of tergum VI short, curved to right at approximately 60 degrees, dilated distally ( Fig. 5 B). Medial lobes of tergum VIII (pseudoparameres) short, symmetrical, posterior margin straight to slightly convex, posterolateral corners roundedly angled ca. 45 degrees ( Fig. 5 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 membranous and papillose, both lightly sclerotized ( Fig. 5 E). Parameres symmetrical, almost as long as wide, mesal margin straight, row of long dark setae emanating from middle of dorsal surface. 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. 5 D).

Brachypterous female. Paratypes (n = 8), length 7.68–8.24 (mean = 7.90); maximum width 4.40–4.64 (mean = 4.58). Similar to male in general structure and coloration except as follows: Hemelytra surpassing posterior margin of tergum VI. Mediosternite VII (subgenital plate) width 1.5× length; length at midline 0.84; maximum width 1.30; posterior margin straight with small central concavity; posterolateral corners rounded, slightly produced caudad ( Fig. 5 F).

Macropterous male. Paratypes (n = 2), length 7.76–7.92 (mean = 7.84); maximum width 4.56. Setation, posterolateral corners of pronotum, scutellum proportions, embolium length generally same as for brachypterous male. Otherwise head with dark brown stripe at midline becoming wider posteriorly. Scutellum with light brown on anterior corners. Hemelytra solid black, surpassing apex of tergum V, length 5.92 (chord measurement). Clavus without thin, yellow stripe at apex, length 4.3× width, length 2.60, width 0.60; claval commissure length 0.76. Hind wings extending to posterior margin of tergum V. Each laterotergite dark brown in anterior half and light brown posteriorly giving checkered appearance.

Macropterous female. Unknown.

Variation. Some brachypterous specimens from Guatemala and the four localities in Mexico presented a similar dark color pattern to that described for the macropterous male, although one of the dark brachypterous males also exhibited a thin, yellow stripe at the apex of the clavus as in the holotype. The posterolateral corners of the female subgenital plate can be slightly pointed.

Diagnosis. This species presents a characteristic color pattern on the hemelytra with light brown along the middle and along the posterior and lateral margins of the corium that is not present in any other species in the subgenus. The pseudoparameres are noticeably short with the posterolateral corners broadly rounded at a 45 degree angle. The posterior margin of the female subgenital plate has a conspicuous, small, central concavity.

Habitat description. The source of the Tzaconejá River is in the western mountains in central Chiapas. The river travels southeastward along the Lacantún Basin to drain into the Lacantún River, close to the border with Guatemala. At the type locality the river channel is wide (ca. 20–30 m) with limestone cobble and bedrock ( Fig. 6 ). The collecting was conducted in riffles and in shallow areas with current by disturbing the substrate and holding the net downstream. This method was particularly difficult at the type locality because mineral deposition had cemented cobbles to the bedrock.

Distribution. This species was collected from rivers in the highlands and western mountain regions of Chiapas state at elevations above 1000 meters, which are part of the Chiapas biogeographic province. We suspect this species also is present in streams of the western mountains of the Sierra Madre de Chiapas and the easternmost limit (Oaxaca) of the Sierra Madre del Sur biogeographic provinces. In Guatemala the species was collected in the central mountains of the Sierra de los Cochumatanes ( Fig. 4 ).

Etymology. The specific epithet refers to the southern Mexican state of Chiapas, where we collected this species, an area that harbors great biodiversity.

Repositories. The holotype and some paratypes will be deposited in the Colección Nacional de Insectos ( Mexico City); additional paratypes will be deposited in the Enns Entomology Museum (University of Missouri), United States National Museum of Natural History (Washington D.C.), and Washington State University (Pullman).

Type material examined (brachypterous unless otherwise noted). HOLOTYPE ♂: MÉXICO: CHIAPAS: Mpio. Altamirano, Cuauhtemoc, Balneario Tzaconejá, Río Tzaconejá, 28-Mar-2015, 1172 m, L-1886 / 16º 41' 17.5'' N, 92º 01' 03.0'' W, Reynoso, Sites, Shepard, Barr, & Reynoso-Hdez. colls. PARATYPES: same data as holotype (1♀ CNIN; 1³ macropterous, 1³, 2♀ UMC; 1♀ USNM); [Mpio. Bochil], 5 mi N of Bochil, CL1090, 4 May 1964, J. T. & M. S. Polhemus (1♀ CNIN; 1³ macropterous, 1♀ UMC); same but / Ambrysus pygmaeus La R. det. J. T. Polhemus (1³ CNIN); Mpio. Ixtapa, Pte. Río Lajas, Río Lajas, 17-May-2012, 1020 m, L-1340 / 16 50' 42.6'' N, 92 54' 01.7'' W, Reynoso-Velasco & Reynoso-Hernández colls. (1♀ UMC); same locality information but 28-Mar-2015, L-1885 / Reynoso, Sites, Shepard, Barr, & Reynoso-Hdez. colls (1³ CNIN; 1³ UMC; 1³ USNM). GUATEMALA: BAJA VERAPAZ: Rio Quilila, Rt 5, old rd to Salama from CA-14, 1355 m, N 15º 13.913', W 90º 17.662', 15 Sept 2009, R. S. Zack & J. Monzon collectors (1♂, 1♀ WSUC).

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 5. Structures of Ambrysus chiapanecus 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 6. Type locality of Ambrysus chiapanecus n. sp. at Río Tzaconejá (Chiapas, México). (A) general habitat, (B) specific calcareous habitat.