Acanthosoma axicia, Tsai & Rédei, 2015

Tsai, Jing-Fu & Rédei, Dávid, 2015, The genus Acanthosoma in Taiwan (Hemiptera: Heteroptera: Acanthosomatidae), Acta Entomologica Musei Nationalis Pragae 55 (2), pp. 625-664 : 640-642

Acanthosoma axicia sp. nov.

( Figs 11–14 , 37–39 , 52 , 76–79 )

Type material. HOLOTYPE: J, TAIWAN: NANTOU CO.: Lishan , 21.xi.2010, ex Pittosporum illicioides (Makino) , leg. C.T.Tang & Y.C. Li; mounted on card, intact; deposited in NMNS ( Figs 76–77 ) . PARATYPES: TAIWAN: NANTOU CO.: same as holotype (1 ♀ NMNS, 1 J [dissected] NCHU) ; Renai, Shihtyutou [= Shizitou], 26.IV.1990, NSMT-I He 36136 (1J NSMT) . TAICHUNG CO.: Dasyueshan logging Rd. 32K, 6.VII.2010, MV lamp, Y.C. Liao leg. (1♀ NCHU) .

Diagnosis. Recognized by the following combination of characters: humeri spiniform, yellowish to pale orange, directed subhorizontally, slightly elevated, gradually narrowed, apically obtuse; hind tibia simple, not dilated (J, ♀); pregenital abdomen with conspicuous black markings at intersegmental sutures dorsally and ventrally ( Figs 11 , 52 ); genital capsule of male with a pair of posteriorly directed, rather straight, apically obtuse lateral projections with inner margins rather straight and enclosing an angle of about 40°, ventral surface rather densely covered by long setae, provided with a distinct tuft of setae apically ( Figs 11–14 ).

Description. Colour. Dorsum and venter rather uniformly stramineous, humeral processes somewhat paler (yellowish to pale orange); abdomen pale yellow, with distinct red suffusion on exposed parts of segments VII (J, ♀), VIII (♀), and dorsal surface of basal portion of genital capsule (J); intersegmental sutures between connexival plates of abdominal segments II–VII each enclosed by a black marking extending in whole width of connexivum, each continuous with a marginal marking on the respective ventrites, dorsal parts (mediotergite + connexival plates) of segment VII (J, ♀) broadly margined with black posteriorly, lateral portions and median, excised portion of ventrite VII of female broadly margined with black at both sides; tergite VIII of female with a large median, posteriorly narrowing triangular marking confluent with a pair of transverse lateral fasciae along basal margin of tergite VIII; lateral and mesal margins of valvifers VIII of female suffused with black ( Fig. 52 ); posterolateral projections of genital capsule of male pale yellowish, inner margins broadly suffused with dark brown; antennal segment I and legs as general body colour, antennal segments II–IV blackish.

Integument and vestiture. Body glabrous except of fine, scattered hairs on appendages and terminalia; mandibular plates and interocular area virtually unpunctured; maxillary plate with an obtuse tubercle anteriad and mesad of antennal insertion; pronotum, scutellum and sclerotized parts of fore wings with rather uniform black punctation except on calli, humeral processes and narrow costal margin of fore wing; punctation of exocorium and neighbouring part of endocorium not conspicuously different; ventral surface of body virtually unpunctured.

Structure. Body elongate oval with distinctly produced humeri, distance between tips of humeral processes about 1.5 times as long as greatest width of body posteriad of humeri. Head 1.1–1.25 times as broad as its median length, about 1.5–1.6 times as broad as interocular distance, finely transversely rugose, anterior portion of clypeus depressed, with a broad median longitudinal groove. Labium projecting between or slightly surpassing mid coxae. Pronotum with anterolateral margin nearly straight anteriorly, then gradually continued in humeral process, therefore deeply emarginate; humeri spiniform, directed subhorizontally, apically rather obtuse. Thoracic pleuron and sternum. Mesosternal carina distinctly surpassing base of head, highly elevated, rather broadly rounded anteriorly; metathoracic scent gland ostiole with a long, slightly arched peritreme.

Male and female terminalia. Male. Genital capsule ( Figs 11–14 ) with a pair of long, robust, scissors-like lateral projections directed posteriad, surpassing apex of membrane by their apical halves, lateral margin nearly straight, apically rounded with a tuft of hairs, dorsal rim nearly V-shaped, ventral rim with a pair of rigid and pigmented denticles and a pair of setal tufts laterad of paramere sockets, ventral infolding densely pilose; dorsal wall of projection with pigmented thickening along basal half of dorsal rim; distal portion of lateral projection slightly curved dorsad in lateral view ( Fig. 13 ). Body of paramere ( Figs 33–36 ) L-shaped, apex transversely bifurcate, anchor-shaped. Female ( Fig. 52 ). Posterior margin of ventrite VII with a deep, shield-shaped median incision margined with black, surrounding valvifers VIII; posterior margin of laterotergites VIII broadly arcuate, posteriorly far surpassing posterolateral angles of abdominal ventrite VII; Pendergrast’s organs of ventrites VI and VII subelliptical, of equal size.

Measurements (3JJ 2♀♀) (in mm). Body length from apex of head to apex of membrane 13.7–14.2 (J) / 15.3–15.6 (♀), from apex of head to line connecting apices of projections of genital capsule 15.7–17.1 (J); greatest width of body posteriad of humeral processes 6.70–7.60; median length of head 1.90–2.36, width across eyes 2.45–2.60, interocular distance 1.55–1.75; length of antennal segments (I) 1.50–1.70: (IIa) 1.75–1.93: (IIb) 1.55–1.70: (III) 2.30–2.40: (IV) 1.95–2.00; median length of pronotum 2.90–3.45, greatest width (across tips of humeri) 10.3–11.6; median length of scutellum 4.25–4.75, width at base 3.85–4.50.

Etymology. The specific epithet is the Latin noun axicia (‘a pair of scissors’) in apposition, referring to the shape of the genital capsule; ending not to be changed.

Bionomics. Some of the examined adults were collected from Pittosporum illicioides Makino (Pittosporaceae) .

Distribution. The species is apparently endemic to Taiwan. The few specimens which we could access were collected in primary forests of high mountains at an altitude of about 1800–2500 m a.s.l.

Remarks. Although the relatively elongate posterolateral projections of the genital capsule superficially resemble the condition found in members of the A. forfex species group, the similarity is only apparent. The narrow, apically rather pointed, dosally unpunctured head, the shape and direction of the humeral process, and particularly the shape of the terminalia of both sexes (posterolateral projections of genital capsule of male robust, with flattened, densely pilose ventral infolding, body of paramere L-shaped, median excision of the posterior margin of ventrite VII of female broad) suggest that the new species is related to Acanthosoma firmatum ( Walker, 1868) .

Figures

Figs 11–19. Acanthosoma spp., males. 11 – A. axicia sp. nov., posterior part of abdomen, ventral view; 12 – same, genital capsule, ventral view; 13 – same, lateral view; 14 – same, dorsal view; 15 – A. laevicorne Dallas, 1851, posterior part of abdomen, ventral view; 16 – A. expansum Horváth, 1905, posterior part of abdomen, ventral view; 17 – same, posteroventral view; 18 – same, genital capsule, posterior view; 19 – same, ventral view. Scales in mm.

Figs 20–44. Acanthosoma spp., right parameres in different views. 20–21 – A. atayal sp. nov.; 22 – A. haemorrhoidale formosanum subsp. nov., holotype; 23 – A. haemorrhoidale ouchii Ishihara, 1950 (China: Sichuan, Mt. Emei, USNM); 24 – A. haemorrhoidale haemorrhoidale (Linnaeus, 1758) (Spain: Fuente Dé, HNHM); 25–28 – A. asahinai Ishihara, 1943; 29–32 – A. fallax sp. nov.; 33–36 – A. pugnax sp. nov.; 37–39 – A. axicia sp. nov.; 40–41 – A. laevicorne Dallas, 1851; 42–44 – A. expansum Horváth, 1905. Scales in mm.

Figs 52–55. Acanthosoma spp., female terminalia, posteroventral view. 52 – A. axicia sp. nov.; 53 – A. pugnax sp. nov.; 54 – A. laevicorne Dallas, 1851; 55 – A. expansum Horváth, 1905. PO6, PO7 = Pendergrast’s organs of ventrites VI and VII, respectively. Scales in mm.

Figs 76–79. Acanthosoma axicia sp. nov. 76–77 – male; 78–79 – female. Scales in mm.