Hebrus alvearensis, Stella & Pall, 2018

Stella, César Adrián & Pall, José Luis, 2018, A new species of Hebrus (Hemiptera: Heteroptera: Hebridae) from Argentina, Zootaxa 4457 (3), pp. 474-480 : 475-477

Hebrus alvearensis sp. nov.

( Figs. 1–5 )

Type locality. Lentic water source located in " La Tradicion " farm, Intendente Alvear, La Pampa, Argentina, 35°14`00" S 63° 35`00" W.

Type material. Holotype: 1 male (macropterous), “Intendente Alvear, 06.ii.2017. “ La Tradicion ” farm, Intendente Alvear, La Pampa, Argentina, 35°17`57" S 63° 37`35" W ”. //male [p, red label] ‘ HOLOTYPUS / HEBRUS / ALVEARENSIS sp. nov. / col. C. A. STELLA/ det. C.A. STELLA & J.L. PALL 2017 ’ (deposited in MHNLPam). Holotype card-mounted, complete.

Paratypes: 2 female (macropterous), “Intendente Alvear, 06.ii.2017. “ La Tradición ” farm, Intendente Alvear, La Pampa, Argentina, 35°17`57" S 63° 37`35" W ”. All paratypes bear the following labels: [p, white label] ‘ PARATYPUS / HEBRUS / ALVEARENSIS sp. nov. / col. C.A. STELLA / det. C.A. STELLA & J.L. PALL 2017 ’ (deposited in MHNLPam) . Paratypes card-mounted, complete.

Description. Macropterous male. Coloration. Head and thorax dark brown. Eyes prominent, reddish black; ocelli light brown. Bucculae yellowish. Legs, rostrum and antenna light brown. Corium dark brown; a pearl-white marking on clavus, reaching (3/4) of metanotal elevation; four whitish spots on basal half of membrane, veins dark brown. Abdomen dark brown to black ( Fig. 2 ).

Vestiture. Pubescence: short and golden on head, pronotum, sides of thorax, mesoscutellum, metanotal elevation, corium, clavus, abdomen, and legs. Mandibular plates with setae very short. Antennomeres IVa and IVb with long golden setae. Tylus with short dense silver setae.

Structure. Body elongate, 3.4× times longer than width at humeral angles. Vertex with median sulcus shallow, hardly visible. Bucculae ventrally curved, posteriorly conical and slightly elevated ( Fig. 3 ); head with three pairs of trichobothria inserted in deep cuticular pits with a clear spot around base of eyes. Labium extending to base of abdomen, with articles I and II reduced, III noticeably longer than IV. Antennomere I stoutest, cylindrical and slightly curved; II clavate; III and IV terete. Antennomeres from longest to shortest: I Ż III> IVb> II Ż IVa; antennomere I shorter than or equal to interocular distance; IV divided by membranous area into IVa and IVb ( Fig. 4 ). Pronotum laterally compressed with numerous deep pits scattered irregularly, much wider across humeral angles than at anterior lobe. Anterior lobe laterally depressed, with an inverted "v" shaped elevation centrally; this surrounded by two lateral grooves and another small groove with grayish blue pruinosity, centrally. Mesoscutellum slightly semicircular. Metanotal elevation short, triangular, about 1.64× wider than long, posteriorly rounded, without any incision; disc of metanotal elevation with raised edges and strong, straight median carina, flanked by two submedian depressions. Metapleuron slightly gibbose, metathorax slightly narrower than pronotum across humeral angles. Hemelytra reaching posterior margin of abdomen. Metafemur slightly curved; metatibia straight, without long setae and metatarsus formed by two segments, first metatarsomere remarkably shorter than second, with apical claws. Male genitalia: pygophore elliptical; paramere hook-shaped with long setae apically, short setae medially, basal region robust, apex robust and rounded ( Fig. 5 ).

Measurements (mm). Male / female. Body length: 1.84/1.94±0.01; head length: 0.50/0.51±0.02; head width: 0.41/0.50±0.05; eye width: 0.11/0.10±0.01; interocular space: 0.21/0.24±0.01; interocellar space: 0.16/0.18; preocellar distance: 0.03/0.03; labium: I 0.04/0.05±0.01, II 0.04/0.05±0.01, III 0.46/0.48±0.03, IV 0.32/0.28±0.08; antennomeres: I 0.20/0.23±0.03; II 0.16/0.15±0.01; III 0.20/0.20±0.01; IVa 0.16/0.16±0.01; IVb 0.18/0.20±0.03;pronotum length: 0.46/0.45±0.01; humeral width: 0.52/0.84±0.01; metanotal elevation length: 0.25/0.25±0.01; metanotal elevation width: 0.41/0.44±0.01; abdomen with hemelytra length: 1.00/0.90±0.15; abdomen without hemelytra length: 1.00/0.90±0.15; abdominal width: 0.66/0.77±0.03; length of metafemur: 0.50/0.52±0.01, metatibia: 0.64/0.62±0.01, metatarsus: 0.22/ 0.24±0.01.

Variation. Without evident sexual dimorphism although the female is slightly larger.

Differential diagnosis and comparatives notes. Body size between 1.84 and 1.95 mm. Bucculae yellowish, ventrally curved, posteriorly conically produced and slightly elevated. Clavus with a pearl-white marking and four whitish spots on the membrane. Metanotal elevation short triangular, without any incision; with raised edges and strong, straight median carina. Male genitalia: pygophore elliptical; paramere hook-shaped, with long setae apically, short setae in the medially, basal region robust, apical end robust and rounded.

Hebrus alvearensis sp. nov. is approximately the same size as Hebrus priscus Drake & Harris, 1943 , which is known from Cuyaba, Brasil. The latter can be easily distinguished because the apex of the metanotal elevation is forked, there are no pale spots on the membrane or pearly-white markings at the clavus, whereas in H. alvearensis the metanotal elevation is posteriorly rounded without any incision and there are spots on the membrane and clavus. In addition, the disc of metanotal elevation of H. alvearensis has a straight median carina, whereas in H. priscus it is imperceptible and dotted.

Hebrus engaeus , the only congener known in Argentina, has important differences with H. alvearensis . It differs specifically in the following unique combination of characters:

Etymology. The specific epithet alvearensis refers to the name of the city where the species was collected. Distribution. Argentina: La Pampa: Intendente Alvear ( Fig.6).

Figures

FIGURES 1–2. (1) Hebrus alvearensis sp. nov. dorsal view, female paratype; (2) Hebrus alvearensis sp. nov. dorsal view, male holotype. Scale bar = 0.5 mm.

FIGURES 3–5. Hebrus alvearensis sp. nov., male, holotype: (3) lateral view of right buccula; (4) dorsal view of right antenna, (5) paramere of male genitalia.