Hessebius prospinosa, Qiao, Qin, Ma & Zhang, 2019

Penghai Qiao, Wen Qin, Huiqin Ma & Tongzuo Zhang, 2019, Two new species of lithobiid centipedes and the first record of Lamyctes africanus Porath (Chilopoda: Lithobiomorpha) in China, Journal of Natural History 53 (15), pp. 897-921 : 900-904

Hessebius prospinosa sp. nov.

( Figure 2 )

Type locality

Haiyan Countyı Qinghai Provinceı Chinaı 36.92ı769°Nı 100.95ı264°Eı 7 December 2011ı 3044 m above sea levelı collected by Gonghua Lin.

Material examined

♀ holotype (HY4)ı ♀ (HY6)ı

2 Ƌ paratypes (HY3ı HY8).

Diagnosis

Body length 14.2 – 15.8 mm. Antennae with 20 antennomeres; 9 – 11 ocelli on each side arranged in 3 rows. Tömösváry ’ s organ ovalı almost equal in size to neighbouring ocelli ( Figure 2 (e)). Lateral margins of forcipular coxosternite slantingı anterior margin with 2 + 2 smallı blunt teeth and with thick porodonts. Tergites without triangular posterolateral processı a line of setae along posterior border of TT 8ı 10ı 12 and 14. Legs 14 and 15 thicker than anterior ones in both sexes. Coxal pores 4 – 6ı round to ovateı arranged in 1 row. Female gonopods with 2 elongated conical spursı the second article of the female gonopods having a massive process and a strong slightly curved spine. Terminal claw of the third article of female gonopods simpleı with a small triangular protuberance on basal ventral side. Male gonopods short and small.

Remarks

Hessebius prospinosa sp. nov. can be easily distinguished from the other Hessebius species that are known from China by the well-defined tarsal articulation on all legsı the strong spine on the massive expansion projecting from the second article of the female gonopodsı and the terminal claw of the female gonopods having a triangular protuberance on the inner aspect.

Description

Based on holotype (♀)ı body length 14.2 mm; cephalic plate width 1.8 mmı length 1.6 mm.

Colour. Antennae and sternites brown-yellow. Coxosternite light yellow. Distal part of forcipule reddish brown. Legs pale yellowı except legs 14 and 15 reddish brownı claws yellowish brown. Tergites rufousı with headı first tergiteı fifth tergiteı and terminal tergite darker.

Antennae. Length 4.2 mmı 29.5% of body length with 20 + 20 articles. Basal article the same width as lengthı second one markedly longer than wideı following articles gradually shortening and taperingı distal article markedly longer than wideı up to 1.8 times as long as penultimate article. Abundant setae on the surface of antennaeı less so on the basal articlesı gradually increasing in density to about article 5ı then more or less constant.

Cephalic plate. Heart-shapedı smoothı posterior margin concave without median thickening; several symmetric setae scattered along the marginal ridge of the cephalic plate; a strong transverse suture dividing into 2 branchesı projection of lateral marginal discontinuous.

Ocelli. 1 + 4ı 4ı 2 oval to rounded ocelli on each side in 3 irregular rows. Posterior ocellus ovalı larger than the seriate ocelli; seriate ocelli moderately smallı approximately equal in size. All ocelli domedı translucentı usually darkly pigmented.

Tömösváry ’ s organ: ovateı almost the same size as the adjoining ocelliı some distance from the adjoining ocelliı situated on ventral side of cephalic pleurite ( Figure 2 (e)).

Coxosternites. Subtrapezoidal with narrowı very slightly recurved dental margin. Median diastema moderately wideı weakly V-shaped; anterior margin having the teeth developed as smallı blunt bulbs that are encircled by a narrow rimı sclerotisation is markedly greater on the bulbs than on the rims. Porodonts thick and longı lying posterolateral to the most lateral teeth on the ventral side of the coxosternite; some short and long setae scattered on the ventral side of coxosternite.

Tergites. Smoothı without wrinkles. Angles of posterolateral corners of tergites all rounded without triangular projections. T1 narrower than the cephalic plate and T3ı the cephalic plate almost the same width as T3. Posterior margin of TT 1ı 8 straightı continuous. Posterior marginal ridge of TT 3 and 5 concaveı continuous. Posterior margin of TT 7ı 9ı 11ı 12 and 14 slightly convexı T10 slightly concaveı all without ridge. All posterior angles generally roundedı without triangular projections. Lateral marginal ridge of all tergites continuous. Tiny setae scattered very sparsely over the surface. Short to long setae sparsely dispersed along lateral borders and posterior cornersı a band of setae on posterior border of TT 8ı 10ı 12ı 14.

Sternites. Trapeziformı posterior side narrower. SS 1 – 11 glabrousı about 8 – 10 comparatively short to long setae scattered sparsely on anterior and posterior lateral margin of each sternite. Three irregular lines of setae on posterior part of SS 10ı 11. Numerous minute seta surround the surface of SS 12 – 15 except that the middle is glabrous.

Legs. Clear tarsal articulation on all legs. Anterior and posterior accessory spines on legs 1 – 14ı no accessory spurs on leg 15. Anterior accessory spines long and slenderı about 0.5 times the length of principal clawı posterior one slightly strongerı about 0.3 times the length of principal claw. The anterior accessory spines form relatively large angles with the pretarsus. The posterior accessory spines form relatively small angles with the pretarsus. Leg pairs 14 and 15 longer and thicker than 1 – 13. Leg 15 longest of allı with tarsus 1 about 4.0 times longer than wide. Tarsus 2 about 60% length of tarsus 1. Abundant glandular pores on ventral surfaces of femurı tibia and tarsus of legs 14 and 15. Short to moderately long setae scattered over the surface of legs 1 – 13. Tarsi generally more setoseı few setae on legs 14 – 15. Tarsi 1 and 2 of legs 1 – 13 with combs of setae on ventral side. Legs ’ plectrotaxy: as in Table 1 .

Coxal pores. On the left 5664 and on the right 5665ı arranged in a singleı regular rowı circular or ovate. Coxal pore field set in a shallow grooveı with the fringe of coxal pore field distinct.

Female posterior segment. Sternite of female genital segment usually well chitinisedı wider than long; nearly glabrousı fringed with longer setae along the posterior lateral margin. Posterior margin of genital sternite deeply concave between the condyles of gonopodsı except for a smallı medianı approximately tongue-shaped bulge. Female gonopods divided into 3 articles as usual in Lithobiidaeı the first article moderately broadı bearing 28 – 30 short to moderately long setaeı arranged in 4 irregular rows. Seven short to long blunt spines along the dorsolateral ridge of the first article. The first article bearing 2 + 2 moderately longı bullet-shaped spursı inner spur slightly smaller and more anterior than the outer ( Figure 2 (d)). The second article with 5 moderately long setaeı arranged in 2 irregular rows. Nine short to long blunt spines along the dorsolateral ridge of the second article; the dorsal terminal part of the second article of the female gonopods strongly extending backwards and a robust slightly curved spine at the end of the massive projection ( Figure 2 (f)). Five moderately long setae on the surface of third article. Terminal claw simpleı slender and sharp ( Figure 2 (f))ı having moderately small protuberance on ventral-lateral side.

Male posterior segment. Posterior margin of the sternite of the genital segment quite deeply concave between gonopodsı no bulge medially. Gonopods short and smallı only a small hemisphere bulgeı with 4 long setae on surfaceı terminal surface of male gonopods slightly sclerotised.

Variation

Ocelli 1 + 4ı 4ı 2 or 1 + 4ı 3ı 1 or 1 + 3ı 3ı 2 on the cephalic plate. Coxal pores 5664ı 5555ı 5665 in female; 5565ı 5554ı 5555 in male.

Habitat

Specimens were collected under railway stones.

Etymology

The specific name refers to the strong spine on the massive expansion projecting from the second article of the female gonopods ( Figure 2 (f)).

Figures

Figure 2. Hessebius prospinosa sp. nov.ı (a–c): paratypeı male: (a) habitusı dorsal viewı scale 1 mm; (b) forcipular coxosterniteı ventral viewı scale 500 μm; (c) posterior segments and gonopodsı ventral viewı scale 500 μm; (d–f) holotypeı female: (d) posterior segments and gonopodsı ventral viewı scale 500 μm; (e) ocelli and Tömösváry’s organı lateral viewı scale 250 μm; (f) right gonopodı lateral viewı scale 250 μm.