Strigamia svenhedini ( Verhoeff, 1933 )

Yu, Yifei, You, Chunxue & Jiang, Chao, 2025, Taxonomy of the Strigamia centipedes from the East Asian mainland (Geophilomorpha, Geophilidae), Zoosystematics and Evolution 101 (4), pp. 2065-2101 : 2065-2101

Strigamia svenhedini ( Verhoeff, 1933)

Figs 1 A , 2 , 9 J

Paraplanes svenhedini Verhoeff, 1933: 23, 24, figs 15, 16.

Strigamia svenhedini : Bonato et al. 2012: 19 , figs 10, 15.

Material examined.

China – Chongqing • 1 ♂ ( CMMI 20250507013 D ), Wuxi County, Yintiaoling Nature Reserve, Linkouzi Protection Area, Heping ( 31.4747°N, 109.8646°E), 1290 m asl., 07. v. 2025, leg. Yifei Yu ; • 1 ♀ ( CMMI 20250509003 D ), Wuxi County, Yintiaoling Nature Reserve, Hongqi Protection Area, Shuangtong Reservoir ( 31.3128°N, 109.4932°E), 1260 m asl., 9. v. 2025, leg. Yutong Zhang & Hongyan Zhang . – Gansu Province • 1 ♀ ( CMMI 20230921001 D ), Gannan Tibetan Autonomous Prefecture, Zhuoni County, Yeliguan National Forest Park ( 34.9587°N, 103.5565°E), 2390 m asl., 21. ix. 2023, leg. Tianyun Chen, Jiabo Fan & Yiying Zhao ; • 1 ♂ ( CMMI 20220123108 ), Tianshui, Qingshui County, Shanmen Town , 23. i. 2022, leg. Quanyu Ji . – Shaanxi Province • 1 ♀ ( CMMI 20230730002 D ), Mei County, Honghegu National Forest Park ( 34.0955°N, 107.7511°E), 1030 m asl., 30. vii. 2023, leg. Tianyun Chen & Yuan Xiong . – Sichuan Province • 1 ♂ ( CMMI 20210417118 ), Baoxing County, Fengtongzhai Town, Fengda Road ( 30.5341°N, 102.9410°E), 1810 m asl., 17. iv. 2021, leg. Chao Jiang ; • 1 ♂, 3 ♀♀ ( CMMI 20230728001 D – 004 D), Baoxing County, Mt. Jiajinshan ( 30.8670°N, 102.6787°E), 3890 m asl., 28. vii. 2023, leg. Chao Jiang ; • 2 ♂♂ ( CMMI 20230804001 D – 002 D), Aba Tibetan and Qiang Autonomous Prefecture, Songpan County, Zhenjiangguan Town ( 32.2961°N, 103.7264°E), 2440 m asl., 4. viii. 2023, leg. Chao Jiang ; • 1 ♀ ( CMMI 20230804005 D ), Aba Tibetan and Qiang Autonomous Prefecture, Heishui County, Luhua Town ( 32.1026°N, 102.9643°E), 2360 m asl., 4. viii. 2023, leg. Chao Jiang ; • 1 ♂ ( CMMI 20230730001 D ), Garzê Tibetan Autonomous Prefecture, Kangding County, Xinduqiao Town, Mt. Yala ( 30.2838°N, 101.8379°E), 3210 m asl., 30. vii. 2023, leg. Chao Jiang ; • 3 ♀♀ ( CMMI 20230731001 D – 003 D), Garzê Tibetan Autonomous Prefecture, Luhuo County, Xindu Town, near the junction of Niqu, Daqu, and Xianshuihe River ( 31.4081°N, 100.6863°E), 3120 m asl., 31. vii. 2023, leg. Chao Jiang ; • 1 ♀ ( CMMI 20220903003 ), Aba Tibetan and Qiang Autonomous Prefecture, Songpan County, Baiyang Provincial Nature Reserve ( 32.4790°N, 103.6904°E), 2790 m asl., 3. ix. 2022, leg. Chao Jiang ; • 3 ♀♀ ( CMMI 20210901003 , 20210901005–006), Aba Tibetan and Qiang Autonomous Prefecture, Songpan County, Hongxingyan ( 32.8668°N, 103.8123°E), 3750 m asl., 1. ix. 2021, leg. Chao Jiang ; • 1 ♂ ( CMMI 20220903086 ), Aba Tibetan and Qiang Autonomous Prefecture, Songpan County, Daxing Town, near dazhaizi ( 32.5208°N, 103.6878°E), 2940 m asl., 3. ix. 2022, leg. Chao Jiang . – Yunnan Province • 1 ♀ ( CMMI 20201023144 ), Kunming, Xishan Dist., Longmen Scenic Area ( 24.9608°N, 102.6346°E), 2130 m asl., 23. x. 2020, leg. Chao Jiang & Zhidong Wang .

Diagnosis.

Body length reaching at least 10 mm; number of leg-bearing segments usually 33–59; with transverse suture on the cephalic plate; cephalic pleurite without setae; with 32 pectinate hyaline teeth in the mandible; anterior margin of the second maxillae coxosternite deeply concave; telopodite distinctly longer than coxal projection of the first maxillae; denticle of the tarsungulum sub-triangular, internal and external margins of the forcipular tarsungulum gradually converging all along the tarsungulum; calyx of poison gland ca. 1.4 times as long as wide, situated in the distal half of trochanteroprefemur; metasternites with sparse setae of various sizes; metasternites without mid-longitudinal deep sulcus; pore-fields not on the anterior part; distinct sulcus separating pretergite and intercalary pleurites of the ultimate leg-bearing segment; metasternite of the ultimate leg-bearing segment smooth, with no concave on each side; coxal pores at least 10 on each coxopleuron; the most posterior coxal pore on each coxopleuron distinctly displaced from all other pores.

Description.

General features. Body 10–53 mm long; with 33–59 leg-bearing segments; narrowing forward and towards the posterior tip. Color (in ethanol 75 %) reddish yellow; forcipules darker.

Cephalic capsule (Fig. 2 A, C ) sub-quadratic; ca. 1.2 times as wide as long; all margins convex; areolation uniform on the entire surface, less sclerotized along a distinct transverse suture; setae arranged scattered. Clypeus with rather uniform areolation; sclerotized along the anterior margin and a median triangular area; fading close to the labrum and the paraclypeal sutures; 4 post-antennal setae aligned on the anterior part of the clypeus, grouped in the medial part, and 1 medial prelabral seta on the posterior part of the clypeus. Labrum slightly projecting backwards medially, without distinct mid-piece; marginal denticles absent, with two unordered rows of long slender hyaline filaments along the entire labral margin and further rows of shorter filaments behind.

Antennae (Fig. 2 B ) almost uniform in width; ca. 3.0 times as long as the width of the head. Basal articles only slightly more elongated (article II ca. 0.9 times as long as wide); distal articles stouter (article XIII ca. 0.8 times as long as wide); article XIV ca. 1.9 times as long as wide. Setae gradually denser and shorter from the basal articles to the distal ones. Articles I – IX with distinctly two whorled long setae along with numerous short setae; remaining articles equipped with uniform setae.

Mandible (Fig. 2 D ) with a single pectinate lamella with ca. 32 hyaline teeth.

First maxillae (Fig. 2 E ). Coxosternite entire; uniformly areolate; without lappets; 2 + 2 setae on anterior middle part. Coxal projection sub-triangular; about as wide as long; ventral side with 5 small setae on distal half; dorsal surface with numerous small sensilla on distal half. Telopodite longer than the coxal projection; distinctly articulated; without lappets; ventral side with 4 + 3 long setae and 5 + 3 short setae on distal half; dorsal surface with numerous small sensilla on distal half.

Second maxillae (Fig. 2 E ). Coxosternite entire; uniformly areolate; anterior margin deeply concave, 3 + 4 setae close to the anterior margin. Telopodite composed of three articles; gradually narrowing towards the tip; claws simple; almost straight and gradually tapering on the telopodite.

Forcipular segment (Fig. 2 F ). Tergite sub-trapezoid; with lateral margins convex and subparallel; ca. 2.4 times as wide as long. Coxosternite ca. 2.0 times as wide as long on exposed part; anterior margin moderately projecting with respect to its condyles; anterior border shallow concave medially; coxopleural sutures strongly converging backward. Trochanteroprefemur ca. 1.2 times as wide as long; basal distance between trochanteroprefemora ca. 0.4 times of their basal breadth. Forcipular intermediate articles with slight projections. Tarsungulum ca. 2.0 times as long as wide. Basal denticle of tarsungulum sub-triangular, with distal margin slightly convex, basal margin quite straight and ca. 0.4 times as long as the basal breadth of the tarsungulum. Distal part of the tarsungulum uniformly tapering, its internal margin uniformly curved moderately concave and converging uniformly to the external margin. Calyx of poison gland ca. 1.4 times as long as wide, situated in the distal half of trochanteroprefemur.

Leg-bearing segments (Fig. 2 G ). Tergite 1 wider than metatergite 2; lateral margins converging backward. Metasternites sub-rectangular; with sparse setae of various sizes; without a deeply mid-longitudinal sulcus. Posterior pair of sub-ovoid pore-fields present in all metasternites from 1 to penultimate. Pore-fields present also on all procoxae and metacoxae from 1 to penultimate. Legs 1 smaller than the others; pretarsus claw-like, reaching ca. 1 / 3 of the length of the tarsus.

Ultimate leg-bearing segment (Fig. 2 H – K ). Pretergite and intercalary pleurites separated by distinct sulcus; pretergite ca. 2.4 times as wide as long on exposed part. Metatergite ca. 1.2 times as wide as long; sub-trapezoid. Metasternite sub-trapezoid; ca. 1.8 ( ♀), 1.3 ( ♂) times as wide as long; lateral margins slightly concave to nearly straight, converging backwards; posterior margin ca. 0.3 times as wide as anterior margin; with sparse setae of various sizes. Coxal pores 10–13 ( ♀), 10–11 ( ♂) on each coxopleuron (16–17 coxal pores in Verhoeff, 1933); opening independently; all coxal pores distinctly aggregated close to the lateral margins of the metasternite with the possible exception of a single pore on each coxopleuron, diameter of the coxal pores similar to that of the respective ducts; male setae slightly denser close to the ventral posterior edge of the coxopleuron, female sparse. Ultimate leg ca. 1.2 times as long as penultimate leg, male distinctly swollen, ventral and lateral sides with very dense setae, female sparse. Ultimate pretarsus a claw; ca. 0.3 ( ♂), 0.4 ( ♀) times as long as tarsus.

Postpedal segments (Fig. 2 H, J ). Male: intermediate sternite distinct and exposed; first genital sternite separated from pleurites by distinct sutures; gonopods bi-articulate, with setae; penis conical; anal pores present. Female: intermediate sternite indistinct, medially not exposed; first genital pleurosternite ca. 2.6 times as wide as long, posterior margin slightly concave, uniformly with sparse setae; gonopods lamina bilobate, with sparse setae; anal pores present.

Remarks.

Through detailed morphological comparisons of our specimens with published descriptions and illustrations ( Verhoeff 1933: fig. 15; Bonato et al. 2012: figs 10, 15), we observed no significant differences in the following characteristics: coxal pore arrangement (one posterior pore distinctly separated from the others), shape of the ultimate sternite, and morphology of the forcipular segment. The ventral pore distribution deviated slightly from the illustrations ( Verhoeff 1933: fig. 16) but aligned with the original textual descriptions.

This species is widely distributed across southeastern mainland Asia, from Central China to Indochina ( Bonato et al. 2012). However, a record from Thailand ( Bonato et al. 2014) was confirmed as a distinct species, Strigamia inthanoni Bonato, Bortolin, Drago, Orlando, Dányi, 2017 , and was therefore removed from its distribution ( Bonato et al. 2017). As the distribution of this species in China is mainly concentrated in the southwest and western regions, and it has not been recorded in other regions, the records from Taiwan may require further validation.

Distribution.

China ( Gansu, Guangxi, Shaanxi, and Sichuan Provinces, Chongqing).

Figures

Figure 1. Forcipular segments of Strigamia spp. (A – M). A. S. svenhedini (Verhoeff, 1933) (spm. CMMI 20220903086); B. S. japonica (Verhoeff, 1935) (spm. CMMI 20231128001 D); C. S. tenuiungulata (Takakuwa, 1938) (spm. CMMI 20230414002 D); D. S. bicolor Shinohara, 1981 (spm. CMMI 20210227106); E. S. platydentata Shinohara, 1981 (spm. CMMI 20210702003 D); F. S. korsosi Bonato, Bortolin, Drago, Orlando, Dányi, 2017 (spm. CMMI 20191031044); G. S. laterisetosa sp. nov., holotype; H. S. longiglanda sp. nov., holotype; I. S. dianguiensis sp. nov., holotype; J. S. obliquidentata sp. nov., holotype; K. S. xizangensis sp. nov., paratype; L. S. ziyunensis sp. nov., holotype; M. S. asiatica sp. nov., holotype. N, O. live specimens of S. laterisetosa (Zhoushan, Zhejiang Province, China; photo by Chao Jiang). Scale bars: 250 μm (A – M).

Figure 2. Strigamia svenhedini (Verhoeff, 1933). A. Cephalic plate, dorsal; B. Left antenna, ventral; C. Anterior part of cephalic capsule, ventral (forcipules, maxillae and mandibles removed); D. Mandible; E. Maxillary complex, ventral; F. Forcipular segment, ventral (venom canal drawn with dashed lines); G. Sternum of leg-bearing segment, ventral (setae on left part omitted); H. Posterior end of body in adult female, ventral (setae on left coxopleuron and ultimate leg omitted); I. Ditto, dorsal (setae on right coxopleuron and ultimate leg omitted); J. Posterior end of body in adult male, ventral (setae on left coxopleuron and ultimate leg omitted); K. Ditto, dorsal (setae on right coxopleuron and ultimate leg omitted). Areolation drawn in part in A, D, E. Specimens: ♂ (CMMI 20230728002 D) (A – G, J – K); ♀ (CMMI 20230731001 D) (H, I). Scale bars: 100 μm (D – G); 250 μm (B, H, I); 500 μm (A, C, J – K).

Figure 9. Strigamia dianguiensis sp. nov., holotype. A. Head and anterior trunk segments, dorsal (most part of antennae, legs omitted); B. Right antenna, ventral; C. Anterior part of cephalic capsule, ventral (forcipules, maxillae and mandibles removed); D. Mandible; E. Maxillary complex, ventral; F. Forcipular segment, ventral (venom canal drawn with dashed lines); G. Sternum of leg-bearing segment, ventral (setae on right part omitted); H. Posterior end of body in adult female, ventral (setae on left coxopleuron and ultimate leg omitted); I. Ditto, dorsal; J. Sternum of leg-bearing segment, ventral. Areolation drawn in part in A, C, E. Specimens: Strigamia dianguiensis sp. nov. (A – I); S. svenhedini (J). Scale bars: 250 μm (A, F – I); 100 μm (B – E, J).