Ambrysus shorti Sites

Sites, Robert W., 2015, New taxa of Cryphocricinae (Heteroptera: Naucoridae) from the Guiana Shield: Hygropetrocoris Sites, n. gen. and two new species of Ambrysus Stål, Zootaxa 4033 (3), pp. 427-438 : 435-437

Ambrysus shorti Sites NEW SPECIES

Fig. 6

Description. Macropterous male. HOLOTYPE, length 6.64; maximum width 3.32. General shape elongate, parallel-sided; widest across embolia ( Fig. 6 A). Overall dorsal coloration medium brown, legs lighter, wing membrane darker. Dorsal surface coarsely punctate. Ventral coloration entirely yellow except propleuron infuscated near middle.

Head. Head length 1.16; maximum width 1.46. Brown posterior coloration extending anteriorly along inner margin of eyes and at midline, yellowish brown anteriorly; coarsely punctate. Eyes convergent anteriorly, synthlipsis 0.70; thin band of cuticle along posterolateral margin of eye; eyes flat and not raised above level of vertex or pronotum. Anterior margin between eyes slightly convex, extending anteriorly in front of eyes 7% of head length; posterior margin between eyes strongly convex, extending posteriorly 39% of head length. Labrum width 1.6× the length, evenly rounded, with sparse long hairs. Labium with three visible yellowish brown segments, darkening distally, extending 0.40 beyond labrum not including extruded stylets. Antennal proportions 2:7:13:8, length 0.59, segment 3 extending to lateral margin of eye, elongate hairs on segment 4 and distal half of 3.

Thorax. Pronotum coarsely punctate; transverse sulcus marking anterior border of transverse band in posterior 1/4; transverse band pale yellow in anterior half, brown in posterior half; pronotum anterior to transverse band mostly brown in middle half with teardrop-shaped pale marking at midline at anterior margin of transverse band; lateral portions mostly yellowish brown with dark markings including a thin, longitudinal, midlateral stripe; lateral margins convergent, mostly straight, convex at level of eyes, with sparse row of elongate setae, explanate; posterior margin approximately straight in middle 3/4, lobed posteriorly above wing bases; anterior margin deeply concave between eyes to embrace convex posterior margin of head; posterolateral corners rounded; width 2.9× the length; length at midline 1.08; maximum width at posterolateral corners 3.10. Prothorax ventrally pruinose medially, with broad glabrous band along lateral margin in posterior half arcuately becoming narrower at midlength and gradually narrowing anteriorly; apices of propleura meeting broadly at midline, separated from level of prosternellum; propleuron dark lateral and posterior to coxa; propleuron with medial 2/3 of posterior margin with elongate golden setae. Probasisternum yellow, with sharp medial carina and generally appearing pruinose with row of setae lateral to carina. Prosternellum mostly yellow, darker medially, extending beneath apices of propleura. Mesoscutum alternating pale yellow and brown across width, lateralmost pale yellow marking extending posteriorly onto mesoscutellum; scutoscutellar suture suppressed laterally. Scutellum coarsely punctate, triangular, entirely brown with small yellow marking at each corner, width 1.8× the length, width 2.16, length 1.20. Hemelytra densely punctate. Clavus with yellow transverse stripe at base; claval commissure dark brown, length 0.64. Embolium length 2.14, greatest width 0.42; lateral margin straight in anterior 3/4, slightly convex posteriorly, yellow brown in anterior 2/3, becoming darker posteriorly. Oblique suture connecting claval and embolar sutures near bases. Hind wings well developed. Mesobasisternum midventral tumescence negligible, with sulcus on midline continuing through triangular mesosternellum. Metasternellum (= metaxyphus) transverse, subtriangular, with apex acute.

Legs. All legs yellow except forelegs light brown dorsally. Profemur with brush of elongate setae in basal 1/4 of posterior margin; 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, with broad longitudinal sulcus that can accommodate flexed femora. Meso- and metafemora with row of short, brown spines on anterior margin; spines restricted to basal half on mesofemur, nearly full length of metafemur. Meso- and metatibiae with ventrolateral, ventromedial, dorsolateral, and dorsomedial rows of stout reddish-brown spines; mesotibia dorsomedial rows include combs of up to three spines; metatibia dorsolateral row includes 7–8 single spines; meso- and metatibiae with one dorsal and three ventral comb rows of reddish-brown spines at apical rim. Meso- and metatibiae and -tarsi with long, pale swimming hairs; hairs profuse on metatibia and -tarsus. Meso- and metapretarsi with paired claws slender, gently curved, with basal tooth. Leg measurements as follows: foreleg, femur 1.76, tibia 1.36, tarsus 0.40; middle leg, femur 1.74, tibia 1.48, tarsomeres 1–3, 0.12, 0.22, 0.34; hind leg, femur 1.90, tibia 2.22, tarsomeres 1–3, 0.14, 0.38, 0.48.

Abdomen. Dorsally with connexiva exposed, each laterotergite yellow anteriorly and brown posteriorly giving checkered appearance ( Fig. 6 A); lateral margin smooth, 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 with mesal margin straight, club large and subtriangular with lateral corner roundedly acute ( Fig. 6 B). Medial lobes of VIII (pseudoparameres) moderately elongate, with apical margin evenly rounded ( Fig. 6 C). Ventrally entirely yellow, pruinose, with pile of fine hairs. Longitudinal band of elongate golden brown hairs beginning on midline of III, widening posteriorly cover mediosternite VIII. Lateral margin with thin, glabrous band. Glabrous patches on laterosternites II–VI. Mediosternite III with midventral ridge, V with posterior margin asymmetrically concave to left, VI asymmetrically convex to left. Phallosoma elongate, linear, constricted basally, left side rounded and right side angled near apex ( Fig. 6 D). Parameres symmetrical, mostly covered with numerous tentacular setae originating on lateral half, extending mesad ( Fig. 6 D). Pygophore with elongate setae sparsely distributed over most of surface, with thick brush of elongate setae on posterior margin ( Fig. 6 D).

Female. Unknown.

Diagnostic features. This small, remarkably parallel-sided species is precisely twice as long as wide. The sides of the pronotum and most of the embolium are straight. The tentacular setae of the parameres are unique among known species of Ambrysus .

Etymology. The specific epithet " shorti " honors Dr. Andrew E. Z. Short, University of Kansas, who graciously made this and other naucorid specimens available to me for study.

Repository. The holotype is deposited in Museo del Instituto de Zoologia Agrícola, Maracay, Venezuela.

Material examined. HOLOTYPE ♂. VENEZUELA: Amazonas State, Region 9, Kusad Mts., Mokoro Creek near rockslide area, 5° 23.207'N, 67° 36.922'W, 125 m, Tobogon de la Selva, 14.i.2009, detrital rock pools, leg. K. Miller, VZ09-0114-01E.

Figures

FIGURE 6. Ambrysus shorti n. sp. (A) dorsal habitus; (B) 6 th and 7 th abdominal terga; (C) 8 th abdominal tergum showing medial pseudoparameres; (D) pygophore with phallosoma and parameres with (left) and without (right) terga IX and X (proctiger), size bar = 0.5 mm.