Xenorhyncocoris attractivus, Chen & Liu & Cai, 2021

Chen, Zhuo, Liu, Yingqi & Cai, Wanzhi, 2021, Taxonomic review of Xenorhyncocoris Miller (Heteroptera: Reduviidae: Ectrichodiinae), with description of X. attractivus sp. nov. and notes on sexual dimorphism of the genus, European Journal of Taxonomy 746 (1), pp. 26-49 : 33-40

Xenorhyncocoris attractivus sp. nov.

urn:lsid:zoobank.org:act:6AA758C6-87A6-40B8-A84E-3BFE76CCABB6

Figs 12–45

Diagnosis

Macropterous male: as in generic diagnosis. Micropterous female: body length about 33.4 mm; blackish brown; head 1.8 times as long as pronotum; anteocular part 1.45 times as long as postocular part; labial segment II 1.65 times as long as segment III, reaching posterior margin of eye, strongly curved dorsally, closing to ventral surface of head; pronotum 1.15 times as broad as its length, anterior lobe moderately swollen, posterior lobe 1.15 times as broad as anterior lobe; prosternum reaching middle of mid coxae; scutellum erect; fore wing reaching middle of scutellum.

Etymology

The specific epithet ʻ attractivus ʼ (meaning ʻinterestingʼ) refers to our first impressions of this new species.

Material examined

Holotype MALAYSIA • ♀; Sabah, Mt Trus Madi ; 5.44881° N, 116.45239° E; 1180 m a.s.l.; May 2017; W. Zhang leg.; CAU-RE-0000004 .

Paratypes MALAYSIA • 1 ♂; same locality as for holotype; 19 Aug. 2016; Y. Zhao leg.; CAU-RE-0000006 • 1 ♂; same locality as for holotype; 10 Feb. 2017; Y. Liu leg.; CAU-RE-0000007 • 1 ♂; Sabah, Tawau Hills Park ; 4.38611° N, 117.88833° E; 12 Mar. 2014; I. Kamskov leg.; CAU-RE-0000005 .

Description

Macropterous male

MEASUREMENTS [in mm, n = 3 (paratypes)] ( Figs 12–14 ). Length of body (to apex of abdomen) = 26.60–28.70; length of head = 6.50–6.70; length of anteocular part = 3.20–3.30; length of postocular part = 2.10–2.20; width across eyes = 3.10–3.15; interocular space = 1.00; interocellar space = 0.20– 0.25; length of antennal segments I–IV = 4.30–4.60, 5.50–5.90, 1.80–2.00, 2.40–2.60; length of labial segments II–IV = 3.80–4.10, 2.50–2.60, 1.80–2.00; length of pronotum = 4.80–5.00; length of anterior pronotal lobe = 1.70–1.80; length of posterior pronotal lobe = 3.10–3.20; width of anterior pronotal lobe = 3.70–3.80; width of posterior pronotal lobe = 6.70–6.90; median length of scutellum = 1.40; basal width of scutellum = 3.10–3.40; apical prongs space = 1.20–1.40; length of fore femur, tibia, tarsus = 5.80–6.00, 6.50–6.70, 1.70–2.00; length of mid femur, tibia, tarsus = 5.50–5.80, 5.90–6.30, 1.70–1.90; length of hind femur, tibia, tarsus = 7.70–8.60, 8.50–9.30, 2.00–2.30; length of fore wing = 17.10–18.00; length of abdomen = 14.50–15.75; maximum width of abdomen = 8.80–9.70.

COLORATION. As in generic description.

STRUCTURE. Body shape and vestiture as in generic description. Head ( Figs 18–20 ) with anteocular part 1.5 times as long as postocular part; interocular space slightly narrower than diameter of single eye; antennal scape 1.4 times as long as anteocular part; labial segment II 1.55 times as long as segment III, with apical ⅔ curved dorsally, approaching ventral surface of head ( Fig. 19 ). Pronotum ( Figs 18–19 ) 1.4 times as broad across humeral angles as its length; posterior lobe 1.8 times as long as, and 1.8 times as broad as anterior lobe; prosternum ( Fig. 20 ) reaching middle of mesosternum; scutellum ( Fig. 18 ) with apical prongs well developed and widely separated basally, lateral prongs papilla-shaped.Abdomen 1.65 times as long as its maximum width.

MALE GENITALIA. Pygophore ( Figs 26–28 ) rounded posteriorly, with posterior margin edge-liked; median process broad, lamelliform, apex rounded; paramere insertion with a protuberance ( Fig. 26 ). Parameres ( Figs 29–32 ) bent and slightly twisted at midpoint, with an obtuse subapical process. Phallus (33–36) with articulatory apparatus thick; basal plates arched, basal plate bridge relatively thin; basal plate extension short and thick; dorsal sclerotized plate posteriorly narrowed, apically rounded, with 1+1 paralleled rows of tiny denticles at apical half ( Fig. 33 ); lateral process of dorsal sclerotized plate flake-like, apex with about seven tiny denticles ( Fig. 36 ); struts converged anteriorly, parallele in most of their length and fused at midpoint; endosoma with a broad, flattened, laterally reflexed sclerite ( Figs 33, 35–36 ); ventral surface of phallus with 1+1 blade-like, apically sharped sclerites ( Figs 34–35 ).

Micropterous female

MEASUREMENTS [in mm, n = 1 (holotype)] ( Figs 15–17 ). Length of body (to apex of abdomen) = 33.40; length of head = 9.80; length of anteocular part = 4.60; length of postocular part = 3.20; maximum width of head = 4.55; width across eyes = 3.90; interocular space = 1.90; length of antennal segments I–IV = 4.50, 6.00,? (missing),? (missing); length of labial segments II–IV = 6.60, 4.00, 2.50; length of pronotum = 5.40; length of anterior pronotal lobe = 3.70; length of posterior pronotal lobe = 1.80; width of anterior pronotal lobe = 5.50; width of posterior pronotal lobe = 6.20; median length of scutellum = 1.30; basal width of scutellum = 3.30; apical prongs space = 1.40; length of fore femur, tibia, tarsus = 7.80, 8.40, 2.10; length of mid femur, tibia, tarsus = 7.80, 8.00, 2.20; length of hind femur, tibia, tarsus = 10.00, 10.90, 2.30; length of fore wing = 1.20; length of abdomen = 16.40; maximum width of abdomen = 12.10.

COLORATION. Body generally blackish brown; apical ⅓ of antennal pedicel, middle spot near posterior margin of abdominal sternite VII and valvula I yellowish brown. Other body parts as in generic description.

STRUCTURE. Body shape and vestiture as in generic description. Head ( Figs 37–40 ) 1.8 times as long as pronotum, 2.15 times as long as its maximum width; anteocular part 1.45 times as long as postocular part; antennal scape as long as anteocular part; labial segment II 1.65 times as long as segment III, reaching posterior margin of eye, with apical ¾ distinctly curved dorsally, approaching ventral surface of head ( Fig. 38 ); labial segment III moderately inflated ( Figs 38–39 ). Pronotum ( Figs 37–38 ) 1.15 times as broad across humeral angles as its length; anterior lobe two times as long as posterior lobe; posterior lobe 1.15 times as broad as width of anterior lobe; prosternum ( Fig. 39 ) reaching middle of mid coxae; scutellum ( Fig. 41 ) broad, erect, with apical prongs short. Fore wing ( Fig. 41 ) scale-like, short, reaching middle of scutellum. Abdomen ovoid, 1.35 times as long as its maximum width.

FEMALE GENITALIA ( Figs 42–43 ). As in generic description.

Distribution

Malaysia (Sabah: Mt Trus Madi).

Comparative notes

Because the males of other species of Xenorhyncocoris are unknown, the following comparisons are based on females. Xenorhyncocoris attractivus sp. nov. resembles X. caraboides in the dorsally curved labial segment II, but it can be easily distinguished from the latter by: the much smaller size (body length 33.4 mm in X. attractivus sp. nov. vs about 37 mm in X. caraboides ); head 1.8 times as long as pronotum (vs 2.2 times as long as pronotum in X. caraboides ); anteocular part 1.45 times as long as postocular part (vs 1.3 times as long as postocular in X. caraboides ); labial segment II reaching posterior margin of eye, 1.65 times as long as segment III (vs distinctly surpassing posterior margin of eye, 1.9 times as long as segment III in X. caraboides ); apex of prosternum reaching middle of mid coxae (vs almost reaching posterior margins of mid coxal cavities in X. caraboides ).

Xenorhyncocoris attractivus sp. nov. can be separated from X. schoenitzeri by: anteocular part 1.45 times as long as postocular part (vs 1.7 times in X. schoenitzeri ); labial segment II dorsally curved, segment III moderately inflated (vs labial segment II straight, apically bulbous, segment III strongly inflated in X. schoenitzeri ); pronotum 1.15 times as broad as its length (vs width of pronotum equal to its length in X. schoenitzeri ); posterior pronotal lobe 1.15 times as broad as width of anterior lobe (vs posterior lobe as broad as anterior lobe in X. schoenitzeri ).

Xenorhyncocoris attractivus sp. nov. is most similar to X. princeps in the shape of the head and the moderately inflated labial segment III. The new species differs from the latter by the following characters: labial segment II dorsally curved, 1.65 times as long as segment III (vs labial segment II straight, apical ⅔ of ventral surface slightly thickened, 1.9 times as long as segment III in X. princeps ); pronotum 1.15 times as broad as its length (vs width of pronotum equal to its length in X. princeps ); posterior pronotal lobe 1.15 times as broad as width of anterior lobe (vs posterior lobe as broad as anterior lobe in X. princeps ); apex of prosternum reaching middle of mid coxae (vs reaching anterior margins of mid coxal cavities in X. princeps ).

Moreover, several additional characters can also distinguish X. attractivus sp. nov. from its congeners: the blackish brown body color (vs brown in other species); the ~90° erected scutellum (vs ~45° suberected scutellum in other species); apex of fore wing reaching middle of scutellum (vs surpassing middle but not reaching apex of scutellum in other species). Species of the genus Xenorhyncocoris can be distinguished with the key above.

Figures

Figs 12–17. Xenorhyncocoris attractivus sp. nov., habitus. 12. Paratype, ♂ (CAU-RE-0000005), dorsal view. 13. Same, lateral view. 14. Same, ventral view. 15. Holotype, ♀ (CAU-RE-0000004), dorsal view. 16. Same, lateral view. 17. Same, ventral view. Scale bar = 5.00 mm.

Figs 18–25. Xenorhyncocoris attractivus sp. nov., paratype, ♂ (CAU-RE-0000006). 18. Anterior part of body, dorsal view. 19. Same, lateral view. 20. Same, ventral view. 21. Anterior part of right fore leg, dorsal view. 22. Same, lateral view. 23. Right fore wing, dorsal view. 24. Right hind wing, dorsal view. 25. Posterior part of abdomen, ventral view. Scale bars: 18–20, 23–25 = 3.00 mm; 21–22 = 2.00 mm.

Figs 26–36. Xenorhyncocoris attractivus sp. nov., paratype, ♂ (CAU-RE-0000006). 26. Pygophore, dorsal view. 27. Same, lateral view. 28. Same, caudal view. 29–32. Paramere. 33. Phallus, dorsal view. 34. Same, lateral view. 35. Same, ventral view. 36. Same, front view. Scale bar: 26–32 = 1.00 mm; 33–36 = 0.75 mm.

Figs 37–43. Xenorhyncocoris attractivus sp. nov., holotype, ♀ (CAU-RE-0000004). 37. Anterior part of body, dorsal view. 38. Same, lateral view. 39. Same, ventral view. 40. Head, dorsal view. 41. Scutellum, dorsal view. 42. Posterior part of abdomen, ventral view. 43. Same, caudal view. Scale bars: 37–39, 42–43 = 3.00 mm; 40–41 = 2.00 mm.

Figs 44–45. Xenorhyncocoris attractivus sp. nov. 44. Living male. 45. Living female. © Weiwei Zhang.