Hemisphaerius bresseeli sp. nov.

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Figs 2F, 5–9

Hemisphaerius rufovarius Walker, 1858 – Zhang et al. 2020: 266, fig. 101 pl. 19g –i (described, figured with genitalia, recorded from Hainan, Yunnan and Guangxi).

Hemisphaerius bipunctatus Melichar, 1906 – Lallemand 1942: 70 (listed).

Hemisphaerius testaceus Distant, 1906 – Chen et al. 2014: 64, fig. 2-24 (described, figured with genitalia, recorded from Hainan: Jianfengling, and Taiwan – the latter not substantiated by specimens!).

Diagnosis

Hemisphaerius bresseeli sp. nov. varies in body colour, with tegmina being either red, pale brown or green, with or without black spot (Figs 5–7) but can be recognized by

(1) the shape of anal tube, subtriangular in dorsal view and with posterolateral angles projecting lateroventrad (An – Fig. 8A–D);

(2) the strongly U-shaped lateral aspect of the aedeagus (Fig. 8E–F);

(3) the asymmetrical lateral lobes of the periandrium laminate with outer margin rounded and with numerous small teeth (ll – Fig. 8K);

(4) the ventral lobe of the periandrium apically lanceolate (vl – Fig. 8G, K).

Differential diagnosis

The closest species is H. caninus Che, Zhang & Wang, 2020 (in Zhang et al. 2020), from which H. bresseeli sp. nov. differs by having small teeth along the outer margin of the lateral lobes of the periandrium (outer margins without teeth in H. caninus), by a more elongate anal tube and by the lanceolate apex of the ventral lobe of the periandrium (apex truncate in H. caninus).

Etymology

The species epithet is a patronym dedicated to Joachim Bresseel, stick insect expert, who has worked with us on the Global Taxonomy Initiative project in Vietnam for more than ten years.

Type material

Holotype

VIETNAM • ♂ (dissected, Figs 5, 8); Quang Ninh Province, Dong Son-Ky Thuong Nature Reserve; 21°08′29″ N, 107°04′53″ E; 27 Aug. 2022; 550 m a.s.l.; secondary forest; GTI Project; J. Constant, J. Bresseel and L. Semeraro leg.; I.G.: 34.518; RBINS.

Paratypes

VIETNAM • 2 ♂♂ (dissected), 1 ♀; same collection data as for holotype; RBINS • 1 ♂ (dissected), 2 ♀♀; same collection data as for holotype; VNMN • 1 ♂ (dissected); Vinh Phuc Province, Me Linh [Biological Station]; 21°23′04″ N, 105°42′44″ E; 15 Aug. 2007; [100 m a.s.l.]; H.T. Pham leg.; VNMN • 1 ♂ (dissected – Fig. 7A–D); Tonkin, Hoa Binh; Père De Cooman leg.; R.I.Sc.N.B. I.G. 18.385; “ Hemisphaerius bipunctatus Mel, dét. V. Lallemand 19”; RBINS • 1 ♂ (dissected); Tonkin, Hoa Binh; [Père De Cooman leg.]; R.I.Sc.N.B. I.G. 18.385; [“ Hemisphaerius bipunctatus Mel, dét. V. Lallemand 19”]; RBINS • 1 ♀ (Fig. 7E–H); Tonkin, Hoa Bing; [Père De Cooman leg.]; R.I.Sc.N.B. I.G. 23.285; “ H. Synave det., 195 Hemisphaerius bipunctatus Mel. ”; RBINS .

Notes

(1) on Hemisphaerius bipunctatus Melichar, 1906 .

The specimens identified and recorded as H. bipunctatus Melichar, 1906 by Lallemand (1942) in the RBINS collection were examined (Fig. 7). They are from Hoa Binh in North Vietnam and are not conspecific with the specimens of H. bipunctatus from Singapore and southern Thailand, also in the RBINS collection. The type localities of H. bipunctatus are Perak in Malaysia and Java (Melichar 1906), and the Vietnamese specimens, instead, belong to the new species H. bresseeli sp. nov. as described above. Hence, H. bipunctatus must be removed from the Vietnamese fauna.

(2) on Hemisphaerius rufovarius Walker, 1858 .

Hemisphaerius rufovarius Walker, 1858 (described from Myanmar) was considered by Liang (2001) as a senior synonym of Hemisphaerius virescens Distant, 1906 (described from Myanmar, Tenasserim Valley, Myitta), H. testaceus Distant, 1906 (Myanmar, Tenasserim Valley, Myitta) and H. scymnoides Walker, 1862 (Thailand, Chantaburi). However, this action was not considered by Chen et al. (2014). This explains why the same species was referred to as H. testaceus in Chen et al. (2014), and later as H. rufovarius in Zhang et al. (2020) who followed Liang (2001).

From China

The two specimens recorded as H. rufovarius from Hainan Island (Dwa Bi and Ta Han) by Fennah (1956), representing the first record of the species from China, probably belong to H. bresseeli sp. nov. but were not examined by the authors.

The material referred to as H. testaceus in Chen et al. (2014), and later as H. rufovarius in Zhang et al. (2020) (including specimens from Hainan), according to the corresponding illustration of the male terminalia available in these publications, actually belongs to H. bresseeli sp. nov.

From Vietnam

The first record of H rufovarius from Vietnam (Hoa Binh) was published under the junior synonym H. scymnoides by Fennah (1978) but these specimens are assumed to also belong to H. bresseeli sp. nov. (like the Hoa Binh specimens in RBINS), although we did not examine them. This record served as a base for the later publications recording H. rufovarius from Vietnam (see below in dedicated section).

The holotype of H. rufovarius was examined by the first author (see section on this species below) and is a female, so the relevant male terminalia features to accurately characterize this species are missing. The types of the junior synonyms are also females, except for a syntype of H. testaceus, which is here used as a reference for the senior synonym H. rufovarius . The male terminalia of the species are very different from these of H. bresseeli sp. nov. and, among the numerous specimens of “ rufovarius - like” Hemisphaerius examined by the authors from the area separating the documented distribution of H. bresseeli, and the type locality of H. rufovarius and its synonyms, no specimen matching H. bresseeli was found. Instead, externally similar but clearly different genitalia-wise species were observed (Constant, unpubl. data). Hence, H. rufovarius must be removed from the fauna of China and Vietnam.

Description

MEASUREMENTS AND RATIOS. LT: ♂ (n = 4): 4.3 mm (4.2–4.4), ♀ (n = 3): 4.7 mm (4.6–4.9); LT/BB = 1.5; LTg/BTg = 1.6; BV/LV = 3.5; LF/BF = 1.1.

Note

The bright colour of the live specimens (Fig. 2F) tends to fade in collection specimens with the turquoise colour of the markings on the thorax and head turning to yellow and the rest of the body tending to become more yellowish as well (Figs 5–7).

HEAD (Figs 5A–D, 6A–D, 7A–C, E–G). Vertex strongly broader than long in midline, bright red, flat with median shallow groove and margins not carinate; anterior margin weakly curved, posterior one concave and lateral ones oblique, slightly converging cephalad. Side of head bright red. Frons convex, slightly elongate and weakly rugulose, bright red with turquoise marking at dorsolateral angles; no carina; maximum breadth slightly under level of antennae. Clypeus black with basal transverse red band under frontoclypeal suture, convex, smooth. Labium yellow-brown with last segment longer than broad, about as long as penultimate. Antennae yellow-brown; scape short, ring-shaped; pedicel bulbous.

THORAX (Figs 5A, C–D, 6A, C–D, 7A–C, E–G). Pronotum bright red with 2 subtriangular turquoise markings on disc; very short, about ⅓ the length of mesonotum in midline, extremely narrow behind eyes, slightly rugulose, without median carina, with fine carinae along anterior and posterior margins; disc with small, impressed point on each side of median red line; paranotal lobes red, paler at ventral inner angle, without black marking. Mesonotum bright red with median turquoise line not reaching anterior margin and large triangular turquoise marking on lateral angles; rather short, slightly rugulose with fine transverse carina along anterior margin but without longitudinal carinae. Tegulae coloured as tegmina, red or green.

TEGMINA (Figs 5A, C, 6A, C, 7A–B, E–F). Two main colour morphs: (1) red narrowly marked with bright red on postclaval margin along mesonotum, extending to basal ⅓ of tegmen length; (2) bright green; both morphs often with more or less developed black spot in distal half portion of tegmen; strongly convex, rugulose; longer than broad when taken together in dorsal view; costal margin broadly rounded, apical margin rounded; venation obsolete.

HIND WINGS (Fig. 5E). Pale brown with basal portion suffused with red and cells of distal half irregularly darker; strongly reduced, curved and widening from base to 4/5 of length. Veins indistinct on basal ⅓, reticulate on remaining portion.

LEGS (Figs 5A–D, 6, 7B–C, F–G). Elongate and moderately slender, pale red or green (according to colour morph); all tarsi with black-brown onychium; pro- and mesofemora slightly wider than corresponding tibiae; metacoxae, metatrochanters and moderately broad band along basal ⅔ of outer margin of metafemora, dark brown. Apex of metatibial spines and metatarsal spines, black-brown. Metatibiae with 2 lateral spines on apical ⅓ and 6 apical spines. Metatarsi short with first segment about as long as combined length of remaining segments. Metatibiotarsal formula: (2) 6 / 8–9 / 2.

ABDOMEN (Figs 5B, 6B). Brown with middle and posterior area darker, sometimes black.

MALE TERMINALIA. Pygofer (Py) about 2.4 times as high as long at mid-height in lateral view, with posterior margin strongly rounded in dorsal ⅔, then sinuate in ventral ⅓ in lateral view (Fig. 8A); ventral margin rounded in lateral view (Fig. 8A). Gonostyli (G – Fig. 8A–C) convex, sub-semicircular in lateral view with dorsal margin weakly rounded and ventroapical margin strongly rounded, with emargination at base of capitulum; capitulum (ca) with short and wide neck in lateral view, projecting dorsomesad, with dorsal tooth directed anteromesad and lateral slightly laminate tooth curved lateroventrad, a distinct hump at base of capitulum in caudal view (Fig. 8C). Anal tube (An – Fig. 8A–D) dorsoventrally flattened, subtriangular, slightly wider than long in median line and with anal opening at about basal ⅓, lateral margins evenly diverging and posterior margin nearly straight in dorsal view; dorsal margin straight and ventral margin curved ventrad in lateral view; apical angles strongly projecting lateroventrad; apical margin evenly curved in caudal view. Aedeagus (Fig. 8E–K) asymmetrical, strongly curved, reflexed dorsad at right angle at midlength in lateral view. Ventral lobe of periandrium (vl) laminate, lanceolate apically and shorter than lateral lobes (Fig. 8F–G, K). Lateral lobes of periandrium (ll) laminate with outer lateral margin rounded and bearing regular small teeth in distal portion, a slightly larger one at apical angle; inner margin smooth; right lobe more developed, nearly twice as wide as left one in laterocaudal view (perpendicular to plane of lobes – Fig. 8K). Connective (co – Fig. 8E–F, H–K) strongly developed, corpus connective long and regularly curved in lateral view, tectiductus (te) strongly developed, conical with wide anterior foramen and with crista developed in a single laminate carina.

Note

In the studied material, sexual dimorphism was observed, the males being red (Figs 5, 7A–C) and the females green (Figs 6, 7E–G). However, this will need to be confirmed by a larger sample of specimens.

Biology

Hemisphaerius bresseeli sp. nov. was collected in August on lower vegetation and bushes, in moist evergreen tropical forest at about 550 m in altitude in Dong Son-Ky Thuong Nature Reserve (Fig. 1B).

In other places, it was also collected in moist evergreen tropical forest, at altitudes as low as 100 m in Me Linh Biological Station (Fig. 9B). Specimens were collected in the month of August.

Distribution

Vietnam: provinces of Quang Ninh, Hoa Binh and Vinh Phuc; China: Hainan, Yunnan, Guangxi (Fig. 9A).

Notes

The species was recorded from the following localities in China by Zhang et al. (2020) (S. Chen pers. com. Feb. 2023):

Hainan • Yaxuling, Qiongzhong • Nada • Xinglong Hot Spring • Jianfengling (Jianfeng Mountain) • Jianfengling Tianchi (a lake in Jianfeng Mountain).

Yunnan • Mengla County, Xishuangbanna Dai Autonomous Prefecture .

Guangxi • Pinglongshan (Pinglong Mountain), Fangcheng District, Fangchenggang.

The record of the species, under the name H. testaceus, from Taiwan by Chen et al. (2014: 64) is not associated with specimens or a reference in literature, and the species, either under this name, or under its senior synonym H. rufovarius, is not included in the revision of the Issidae from Taiwan by Chan & Yang (1994). Hence, the species must be excluded from the fauna of Taiwan until a confirmed record becomes available.