Strigamia tenuiungulata ( Takakuwa, 1938 )

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 tenuiungulata ( Takakuwa, 1938)

Figs 1 C , 4

Scolioplanes tenuiungulata Takakuwa, 1938: 236, 244, figs 14, 15; Takakuwa 1940: 129–130, fig. 143.

Strigamia tenuiungulata : Bonato et al. 2012: 19 .

Material examined.

China – Sichuan Province • 1 ♀ ( CMMI 20230414002 D ), Baoxing County, Dengchigou ( 30.5357°N, 102.9413°E), 1900 m asl., 14. iv. 2023, leg. Chao Jiang .

Diagnosis.

Body length reaching at least 30 mm; number of leg-bearing segments usually 41 ( 43 ♂ – 45 ♀ pairs of leg-bearing segments in Takakuwa, 1938); with transverse suture on the cephalic plate; cephalic pleurite without setae; with 31 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 slender, sub-triangular, internal and external margins of the tarsungulum subparallel along the basal part, gradually converging only along the distal part; calyx of poison gland ca. 1.0 times as long as wide, situated from femur to distal half of trochanteroprefemur; metasternites with dense 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 8 on each coxopleuron; all sparse on the ventral surface of the coxopleuron, distinctly denser close to the lateral margin of the metasternite.

Description.

General features. Body 30 mm long; with 41 leg-bearing segments ( 43 ♂ – 45 ♀ pairs of leg-bearing segments in Takakuwa, 1938); narrowing forward and towards the posterior tip. Color (in ethanol 75 %) reddish yellow; forcipules darker.

Cephalic capsule (Fig. 4 A, C ) sub-quadratic; ca. 1.0 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 2 medial prelabral setae 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. 4 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. 1.3 times as long as wide); distal articles stouter (article XIII ca. 1.0 times as long as wide); article XIV ca. 1.7 times as long as wide. Setae gradually denser and shorter from the basal articles to the distal ones. Articles I – XI with distinctly three whorled long setae along with numerous short setae; remaining articles equipped with uniform setae.

Mandible (Fig. 4 D ) with a single pectinate lamella with ca. 31 hyaline teeth.

First maxillae (Fig. 4 E ). Coxosternite entire; uniformly areolate; without lappets; setae on anterior middle part indistinct. Coxal projection sub-triangular; about as wide as long; ventral side with 4 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 3 + 2 long setae on distal half; dorsal surface with numerous small sensilla on distal half.

Second maxillae (Fig. 4 E ). Coxosternite entire; uniformly areolate; anterior margin deeply concave, 3 + 2 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. 4 F ). Tergite sub-trapezoid; with lateral margins convex and subparallel; ca. 3.0 times as wide as long. Coxosternite ca. 2.2 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. 1.5 times as wide as long; basal distance between trochanteroprefemora ca. 0.5 times of their basal breadth. Forcipular intermediate articles with slight projections. Tarsungulum ca. 2.7 times as long as wide. Basal denticle of tarsungulum sub-triangular, with distal margin slightly convex, basal margin quite straight and ca. 0.3 times as long as the basal breadth of the tarsungulum; internal and external margins of the tarsungulum subparallel along the basal part, gradually converging only along the distal part. Calyx of poison gland ca. 1.0 times as long as wide, situated from femur to distal half of trochanteroprefemur.

Leg-bearing segments (Fig. 4 G ). Tergite 1 wider than metatergite 2; lateral margins converging backward. Metasternites sub-rectangular; with dense 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. 4 H, I ). Pretergite and intercalary pleurites separated by distinct sulcus; pretergite ca. 4.0 times as wide as long on exposed part. Metatergite ca. 1.4 times as wide as long; sub-trapezoid. Metasternite sub-trapezoid; ca. 1.1 times as wide as long; lateral margins slightly concave to nearly straight, converging backwards; posterior margin ca. 0.4 times as wide as anterior margin; with sparse setae of various sizes. Coxal pores 8–9 on each coxopleuron (10 coxal pores in Takakuwa, 1938); opening independently; all sparse on the ventral surface but densely in lateral margin of the metasternite and some of them covered by that; diameter of the coxal pores similar to that of the respective ducts; setae slightly denser close to the ventral posterior edge of the coxopleuron. Ultimate leg ca. 0.8 times as long as penultimate leg, distinctly swollen, with dense setae on ventral and lateral sides. Ultimate pretarsus a claw; ca. 0.4 times as long as tarsus.

Postpedal segments (Fig. 4 H ). Female: intermediate sternite indistinct, medially not exposed; first genital pleurosternite ca. 1.8 times as wide as long, posterior margin slightly concave, uniformly with sparse setae; gonopods lamina bilobate, with sparse setae; anal pores present.

Remarks.

S. tenuiungulata is morphologically similar to S. bicolor Shinohara, 1981 , but could differ in its long and numerous setae, and the internal and external margins of the forcipular tarsungulum being subparallel along the basal part, gradually converging only along the distal part, and the small and pointed basal denticle of the forcipular tarsungulum.

Distribution.

China ( Sichuan Province); North Korea; South Korea.

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 4. Strigamia tenuiungulata (Takakuwa, 1938). A. Cephalic plate, 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 left part omitted); H. Posterior end of body in adult female, ventral (setae on right coxopleuron and ultimate leg omitted omitted); I. ditto, dorsal (setae on left coxopleuron and ultimate leg omitted omitted). Areolation drawn in part in A, C, E. Specimen: ♀ (CMMI 20230414002 D). Scale bars: 250 μm.