Eudigraphis nigricans ( Miyosi, 1947 )

Eudigraphis nigricans ( Miyosi, 1947) View in CoL

Fig. 2 View Figure 2

Monographis takakuwai nigricans Miyoshi, 1947: 7; Takashima and Haga 1950: 23, fig. 2. View in CoL

Eudigraphis takakuwai nigricans View in CoL : Ishii 1988: 957, figs 10, 11; Nguyen Duy-Jacquemin and Geoffroy 2003: 99; Mimizu Club and Minagoshi 2013: 44, 3 photos; Kawano 2017: 14, figs 1–12.

Eudigraphis nigricans View in CoL : Ishii and Tamura (1995) described this species on page 233; Ishii (1999) further discussed it on page 212; Ishii (2002) provided additional information on page 289; Karasawa et al. (2020) recently reviewed the species on page 94 and presented an illustration in figure 4 D.

Material examined.

China • 4 ♂ 2 ♀; Zhejiang, Hangzhou, West Lake ; 30°23'58"N, 120°14'04"E; 23 April 2024; Y. D. Wang leg.; GenBank: PQ 141065; CBF CZHZS 3 GoogleMaps .

Diagnosis.

Ground color of body pale yellowish-brown in dorsal view, but head black. Body dorsally with a pair of belt-like dark brown markings that run slightly off from both of the rims of each segment of body. Antennal article VI has 3 thick basiconic sensilla, and article VII has 2 thick basiconic sensilla.

Description.

Female. With 13 pairs of legs. Measurements: Body length 3.4 mm, caudal bundle 0.5 mm.

Head (Fig. 2 A View Figure 2 ): Eyes comprising 8 ommatidia. The posterior vertex possesses one pair of tufts each arranged in two rows; each anterior row consists of 13 trichomes, and the posterior row consists of 4 (Fig. 2 A View Figure 2 ). Trichomes are depicted in Fig. 2 J View Figure 2 . Trichobothria are equal in size and arranged in an isosceles triangle formation (Fig. 2 A View Figure 2 ). The gnathochilarium’s lateral palps are twice the length of the medial palp. Lateral palps with 13 sensilla, medial palp with 20 sensilla (Fig. 2 F View Figure 2 ). The labrum’s anterior margin is granulated and armed with 3 + 3 lamellar teeth, and the clypeo-labrum with 6 + 6 setae (Fig. 2 E View Figure 2 ).

Antennae: Long antennae with proportions of antennal articles as depicted in Fig. 2 G View Figure 2 . Antennal article VIII with 4 sensory cones, while article VI with 3 thick basiconic sensilla (Fig. 2 I View Figure 2 ); article VII with 2 thick basiconic sensilla (Fig. 2 H View Figure 2 ).

Trunk: Collum with one pair of tufts, each consisting of 44 trichomes, lateral protuberance of collum with 5 trichomes in a row (Fig. 2 B View Figure 2 ). Tergite II, with one pair of tufts each consisting of 45 trichomes (Fig. 2 C View Figure 2 ) connected by a continuous posterior row of trichomes. Tergite III, with one pair of tufts each composed of 52 trichomes (Fig. 2 D View Figure 2 ) and connected by a continuous posterior row of trichomes. Tergites II – X have the same pattern of trichome insertions.

Legs (Fig. 2 K View Figure 2 ): Trochanter, post-femur, tibia, and tarsus I lack setae. Prefemur and femur each with 1 seta (Fig. 2 L View Figure 2 ), coxa I with 1 seta, coxae II – XII with 3–4 setae, coxa XIII with 2 setae, small setiform hair on tarsus II shorter than telotarsus (Fig. 2 M View Figure 2 ). Telotarus is composed of a posterior process, almost as long as the claw, lamella process and a setiform process are present (Fig. 2 N View Figure 2 ).

Telson: Dorso-medial trichomes on each side consist of 5 sockets of trichome a 1–5, a single trichome b, and three large protruding base sockets of trichome c 1–3 (Fig. 2 P View Figure 2 ). Beneath these, there are two bundles of caudal trichomes separated by a very narrow gap. The telson trichomes exist in two forms: those with hooks and those without hooks. The hooked trichomes most commonly with 2–4 hooks (Fig. 2 O View Figure 2 ).

Male. With 13 pairs of legs. Measurements: Body length 3.2 mm, caudal bundle 0.47 mm. Lateral palps with 13 sensilla, medial palp with 21 sensilla. The anterior margin of the labrum is granulated; the clypeo-labrum with 6 + 6 setae. The collum features one pair of tufts consisting of 41 trichomes each. Tergites II and III with one pair of tufts comprised of 42 or 50 trichomes. Coxa I with 1 seta, coxae II – X with 3–4 setae, coxae XI – XII with 2 setae, and coxa XIII with 1 seta. The dorso-medial trichomes on each side are composed of trichomes a 1–4, b, and c 1–3.

Distribution.

China (Zhejiang), Japan.

Remarks.

This species closely resembles Eudigraphis takakuwai Miyosi, 1947 , but differs in possessing a black head.