Australambrysus clavieri Sites, 2023

Sites, Robert W., 2023, The Australambrysus plax (La Rivers, 1967) species complex (Heteroptera: Naucoridae), with descriptions of three new species, Zootaxa 5278 (2), pp. 318-332 : 329-331

Australambrysus clavieri Sites NEW SPECIES

( Figs. 8 , 9 )

Description. Macropterous male. HOLOTYPE, length 7.36; maximum width 4.32. Paratype (n = 1), length 7.36; maximum width 4.24. General shape elliptical; widest across embolia ( Fig. 8a ). Dorsal coloration of head, pronotum, and legs brownish-yellow; hemelytra dark-brown. Dorsal surface coarsely punctate. Ventral coloration of head and thorax orangish-yellow, abdomen with dense golden pubescence.

Head. Head length 1.34; maximum width 1.76. Mostly yellow, with brown midline stripe and two paramedian rows of darker punctures. Eyes convergent anteriorly, synthlipsis 0.70; 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 6% of head length; posterior margin between eyes strongly convex, extending posteriorly 40% of head length. Labrum width 2.1 length, evenly rounded. Labium with three visible yellowish-brown segments, darkening distally, extending 0.38 beyond labrum not including extruded stylets. Antennal proportions 3:5:9:6, length 0.46, extending to near lateral margin of eye, elongate hairs on segment 4 and distal half of 3.

Thorax. Pronotum coarsely punctate, ground color yellowish; transverse sulcus and nearly confluent series of dark-brown punctures marking anterior border of transverse band in posterior 1/4; cuticle irregularly darkened adjacent to posterolateral margin of eye; lateral margins without dark-brown punctures, convergent, shallowly convex, explanate; posterior margin straight; anterior margin deeply concave between eyes to embrace convex posterior margin of head; posterolateral corner truncate, thus with two obtuse angles and straight margin between angles ( Fig. 8a ); width 3.5 length; length at midline 1.10; maximum width at anteriormost posterolateral angle 3.84. Prothorax ventrally pruinose throughout; apices of propleura nearly meeting at midline and concealing much of prosternellum, closely appressed to margins of probasisternum; propleuron orange-brown throughout, but darker along posterior margin; medial 4/5 of posterior margin with elongate, golden setae. Probasisternum with sharp median carina, with row of short setae lateral to carina. Scutellum coarsely punctate, triangular, mostly yellowish, width 2.0 length, width 2.48, length 1.24. Hemelytra densely punctate, dark-brown, surpassing apex of tergum V, length 5.28 (chord measurement). Clavus with thin, yellow transverse stripe at base; intraclaval suture well-developed; claval commissure length 0.72. Embolium length 2.36, greatest width 0.68; lateral margin convex, yellow in anterior 3/4, dark-brown posteriorly. Oblique suture connecting claval and embolar sutures near bases. Hind wings extending to near posterior margin of tergum V. Mesobasisternum midventral tumescence negligible, with sulcus on midline continuing through triangular mesosternellum. Metasternellum (= metaxyphus) transverse, posterior margin concave laterally with apex acute.

Legs. All legs segments brownish-yellow. Profemur posterior margin with row of tightly arranged setae in proximal 3/4, 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; tarsus immovable, one-segmented; pretarsal claw single, minute, triangular. Procoxa with row of brown, elongate anteromedial setae. 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, but sparse and with several combs of two on metafemur. Mesotibia with ventrolateral, ventromedial, dorsolateral, and dorsomedial rows of stout reddish-brown spines; ventromedial and dorsomedial rows intermixed with combs of two to four spines. Metatibia with ventrolateral, ventromedial, dorsolateral, and dorsomedial rows of stout reddish-brown spines. Meso- and metatibia with semi-circlets of spines at apex of dorsal and mesal margins; two comb rows of stout spines near apex of ventral margin. Long, pale swimming hairs on femora and tibiae of middle and hindlegs and metatarsi; 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 1.98, tibia 1.80, tarsus 0.38; middle leg, femur 2.02, tibia 1.80, tarsomeres 1–3, 0.12, 0.28, 0.36; hind leg, femur 2.36, tibia 2.76, tarsomeres 1–3, 0.16, 0.50, 0.50.

Abdomen. Dorsally with lateral margins of III–VIII exposed, each margin mostly yellow, but with brown in anterior half ( Fig. 8a ); lateral margin smooth to shallowly serrate, sparse marginal row of short yellow setae, group of trichobothria near posterolateral corners. Posterolateral corners of II (visible ventrally) –III right angled, IV–VI spinose, VII acute. Accessory genitalic process of tergum VI absent. Medial lobes of tergum VIII (pseudoparameres) with posteromedial corners broadly rounded ( Fig. 8c ). Ventrally entirely golden-brown, with dense pile of fine hairs. Lateral margin with thin, glabrous band. Glabrous elliptical patches near spiracles on laterosternites II–VII. Aedeagus elongate, linear, apex narrowly rounded ( Fig. 8d ); ventral lobes membranous. Parameres asymmetrical with left paramere slightly more attenuated, apical lobe twice as long as wide, with stout spines along distal third of mesal margin, apex rounded, arched at base> 90 degrees, posterior corner right angled and hyaline ( Fig. 8b ). Proctiger short, length 0.7 width. Pygophore with elongate setae sparsely distributed over most of surface, with thick brush of elongate setae on posterior margin, anterior margin convergent to rounded apex ( Fig. 8d ).

Macropterous female. Unknown

Brachypterous male and female. Unknown.

Diagnostic features. The lateral margins of the pronotum of Australambrysus clavieri n.sp. are slightly more convex than those of the other species. Males can be distinguished from A. aguaro n.sp. by the parameres substantially more elongate. The medial lobes of tergum VIII are rounded only at the posteromedial corner and meet the lateral lobes at right angles ( Fig. 8c ).

Habitat description. The holotype and one of the nymphs were recorded from marginal roots in streams.

Distribution. This species is known from only French Guiana.

Etymology. The specific epithet honors my colleague Simon Clavier, aquatic biologist in French Guiana.

Type depository: Enns Entomology Museum, University of Missouri , Colombia, Missouri, USA .

Type material examined. HOLOTYPE ♁. FRENCH GUIANA: Saut Dalles , Sinnamary, 433’21.3”N, 5254’3.4”W, 13 July 2015, roots, S. Clavier ( UMC) . PARATYPE: Crique Bagote, 4.53633, -52.53428, 13 November 2016, A. Cerdan, sandy stream (1♁ UMC; 1-5th instar DNA-extraction #H20 UMC) .

Additional material examined. FRENCH GUIANA: Crique Biche , 4.78654, -52.42851, 10 February 2012, Mathieu Rhone (1 nymph UMC); Takari Tant, Sinnamary, 4.62168, -52.92728, 7 December 2015, D. Bouvier, roots (1 nymph UMC) .

Figures

FIGURE 8. Australambrysus clavieri n.sp. (a) Dorsal habitus of holotype, (b) left and right parameres, (c) abdominal tergum VIII, (d) genital capsule with terga IX and X removed.

FIGURE 9. Distribution records of species in the Australambrysus plax species complex.