Aradus interpositus Hoberlandt, 2023

Heiss, Ernst, 2023, A new species, a new synonymy, a revised generic assignment and new records in some African and Palaearctic Aradidae (Hemiptera: Heteroptera), Zootaxa 5315 (5), pp. 469-478 : 470-472

‘ Aradus interpositus Hoberlandt n. sp. ’

= Aradus congoensis sp. nov.

( Figs 3 , 18, 19 )

Type material. Holotype: ♁ ( Fig. 3 ), ‘COLL. MUS. CONGO / Elisabethville [= Lumumbashi] (A la / lumière) [hw] XI-1959 [partly hw and p] / Ch. Seydel [p] // Holotypus [p] ♁ [hw] / Aradus / interpositus / n. sp. [hw] / Det. L. Hoberlandt19[p]67[hw, red label] // HOLOTYPE ♁ / Aradus / congoensis sp. nov. / des. E. HEISS 2022 [p, red label] ( MRAC). Specimen card-mounted, left fore and middle leg missing, detached pygophore mounted on separate piece of card .

Paratype: ♀, ‘COLL. MUS. CONGO / Elisabethville (A la / lumière) [hw] IX-195[p]9[hw] / Ch. Seydel [p] // Mus. Nat. Pragae [p] / 10 990 [hw] / Inv. [p, orange label] // Paratypus [p] ♀ [hw] / Aradus / interpositus / n. sp. [hw] / Det. L. Hoberlandt19[p]67[hw, red label] // PARATYPE ♀ / Aradus / congoensis sp. nov. / des. E. HEISS 2022 [p, red label] ( NMPC) .

Note. The examined specimens were labelled as types of ‘ Aradus interpositus n. sp. ’ by Hoberlandt, but the description of this purported new species has never been published, thus this name remains unavailable. Here it is confirmed as a new species and described as Aradus congoensis sp. nov.

Diagnosis. This species belongs to the ‘ flavicornis -group’ of African Aradus species, including A. angusticornis Kormilev, 1974 ( Cameroon) , A. apicicornis Kiritshenko, 1955 (syn. A. noctivagus Hoberlandt, 1957 ) ( Madagascar), A. basilewskyi Schouteden, 1952 ( Democratic Republic of the Congo), A. katangae Schouteden, 1952 ( Democratic Republic of the Congo), A. flavicornis Dalman, 1823 (syn. A. marani Hoberlandt, 1957 ) (widely distributed), A. gracilipes Linnavuori, 1978 ( South Sudan), A. pauliani Hoberlandt, 1957 ( Madagascar) , and A. zavattarii Mancini, 1939 ( Ethiopia) . These species are characterized by rather small size (4–6 mm), slender habitus, bicolored antennae and a caudoventral oval opening of male tergite VIII ( Dalman 1823, Mancini 1939, Schouteden 1952, Kiritshenko 1955, Hoberlandt 1957, Kormilev 1974, Linnavuori 1978, Heiss 2013).

Aradus congoensis sp. nov. resembles and is related to A. gracilipes Linnavuori, 1978 , the only species of this group sharing with the new species the whitish antennal segment IV. Aradus congoensis sp. nov. is however distinguished by a more stout habitus, ratio total body length / width of abdomen 2.93 (vs. more slender, ratio 3.17 in A. gracilipes ); shorter antennae, ratio length of antennae / width of head 1.77 (vs. ratio 1.88 in A. gracilipes ) and relatively shorter antennal segment III, ratio III / II 0.66 (vs. 0.75 in A. gracilipes ); and pronotum more stout, ratio width / length 1.83 (vs. wider, ratio 2.04 in A. gracilipes ). Further biogeographic considerations of the type localities of A. gracilipes from South Sudan, at the northern fringe of the tropical forests of the Congo Basin and of A. congoensis sp. nov. from Elisabethville (named Lumumbashi since 1966) near the Zambian border in Katanga Province of the Democratic Republic of the Congo at the SE edge of Congo Basin, may support the proposed assignment to two distinct species.

Description. Male (holotype) ( Fig. 3 ). Macropterous, of reddish-brown colouration.

Head wider than long, antenniferous lobes with acute apices; antennae slender, all segments cylindrical, colouration of I–III reddish brown, IV whitish; length of I / II / III / IV = 0.20 / 0.60 / 0.40 / 0.35 mm; eyes globular, postocular lobes without projections converging posteriorly to constricted collar; vertex with an U-shaped depression on posterior half.

Pronotum about 1.8 times as wide as long, paranota slightly emarginate, rounded at humeri, then straightly converging anteriorly to anterolateral angles; anterior margin concave, posterior margin slightly convex; disk with four longitudinal carinae and carinate humeri. Scutellum triangular with elevated lateral margins; disk raised at base, apex narrowly angulate. Legs long and slender, femora and tibiae cylindrical.

Abdomen. Lateral margins straight, slightly converging posteriorly; hemelytra with complete membrane, corium long, reaching middle of deltg VI; tergite VIII cup-like with bilobate posteriorly produced lobes and an oval caudoventral opening. Tergite IX consisiting of two elongate lobes.

Male genitalia ( Figs 18–19 ). Parameres sickle-shaped, apex pointed; parandria lobate, inner face with pilosity ( Fig. 18 ); tergite IX consisting of two spaced elongate oval sclerites ( Fig. 19 ).

Female (paratype). Basically as male but larger and of more stout habitus.

Measurements (in mm). Holotype (male): Body length 4.55; head width / length 0.77 / 0.87; pronotum width / length 1.37 / 0.75; width of abdomen 1.55. Paratype (female): body length 5.20; head width / length 0.95 / 0.95; antennae I / II / III / IV = 0.20 / 0.60 / 0.40 / 0.35; pronotum width / length 1.60 / 0.75; width of abdomen 1.85.

Etymology. The species epithet refers to the Congo River, the main and largest river draining the Congo Basin and name giving for the Democratic Republic of the Congo ( DRC). Adjective.

Distribution. So far only recorded from the type locality in Lumumbashi, Katanga Province, Democratic Republic of the Congo.

Figures

FIGURES 1–6. 1—‘Aradus africanus’ (unavailable) (= A. gracilipes Linnavuori, 1978), intended paratype from Chad, male; 2—Aradus gracilipes from Chad, male; 3—‘Aradus interpositus’ (unavailable) (= A. congoensis sp. nov.), intended holotype from Democratic Republic of the Congo, male; 4—‘Aradus nuristanicus’ (unavailable) (= A. betulae (Linnaeus, 1758)), intended holotype from Afghanistan, male; 5—‘Carventus machadoi’ (unavailable), intended paratype from Angola, female; 6—‘Neuroctenus arnoldi’ (unavailable), intended holotype from Zimbabwe, male. Scales: 1 mm.

FIGURES 15–19. 15—Brachyrhynchus abyssinicus Bergroth, 1895, female from Ethiopia: Maraquo, habitus. 16— Brachyrhynchus amplicollis (Linnavuori, 1978), male paratype from Sashamanni, left paramere. 17—B. abyssinicus, male from Maraquo, left paramere. 18–19—Aradus congoensis sp. nov., holotype, male genitalia: 18—left paramere; 19—pygophore. Abbreviations: pa = paramere; pr = parandrium; tgIX = tergite IX. Scales:1 mm (15), 0.2 mm (16–19).