Papillacarus (Papillacarus) mammillatus, Ren & Yang & Liang & Xie, 2018

Ren, Guoru, Yang, Maofa, Liang, Wenqin & Xie, Lixia, 2018, Two new species of the subgenus Papillacarus (Oribatida, Lohmanniidae, Papillacarus) from China, Zootaxa 4462 (1), pp. 100-114 : 107-113

Papillacarus (Papillacarus) mammillatus sp. nov.

( Figs 11–20 )

Diagnosis. Body size: 576–604×278–298. Rostrum truncate, medially convex. Prodorsum and the whole surface of notogaster covered with bacilliar papillae. Prodorsal, notogastral and neotrichal setae setiform, with short cilia, and thin, smooth apex. Four transverse bands present on notogaster surface. Bothridial seta pectinate, with 9 branches. Epimeral setal formula: 10-6-3-4. Genital setae setiform, smooth or with short cilia. Adanal setae setiform, barbed bilaterally.

Measurements. Body length 586 (holotype), 576–604 (5 paratypes); body width 287 (holotype), 278–298 (5 paratypes).

Integument. Body yellow-brown. Surfaces of prodorsum, notogaster, subcapitulum, and genital plates covered with bacilliar papillae; legs covered with foveae.

Prodorsum ( Figs 11–13 ). Rostrum truncate, medially convex. All prodorsal setae setiform, with short cilia, and thin, smooth apex. Rostral seta (ro, 78), lamellar seta (le, 81), interlamellar seta (in, 78), posterior exobothridial seta (exp, 98) setiform, smooth. Anterior exobothridial seta (exa, 76), barbed bilaterally. Bothridial seta (bs, 108) pectinate, with 8 branches on one side, and five barbs on the opposite side. Postbothridial transverse band (S b) behind bothridia.

Notogaster ( Figs 11–13 ). Four transverse bands (S2–S5) present on notogaster, S2 and S3 complete, S4 and S5 interrupted. Sixteen pairs of primary notogastral setae and 9–10 pairs of additional neotrichal setae present, all setiform, with short cilia bilaterally or unilaterally and smooth apex. Setae c 1, d 1 and e 1 not reaching the margin of notogaster, seta c 1 shorter than distance c 1– d 1. Neotrichal setae of two types: 2 pairs long (n 7, 80–88; n 9, 100–110) and 7–8 pairs short (20–34). Lyrifissures ia, im, ip, ih distinct, ia laterally to seta c 3, ip anterolateral laterally to f 2, ih laterally to h 3, ips indistinct. Lengths of notogastral setae: c 1 = 36 (35–37), c 2 = 62 (60–63), c 3 = h 1 = h 2 = p 3 = 85 (84–87), d 1 = e 1 = 45 (43–48), d 2 = e 2 = f 1 = f 2 = p 1 = 77 (75–79), d 3 = h 3 = p 2 = 95 (94–97).

Gnathosoma ( Figs 12 , 14–16 ). Subcapitulum longer than wide (130–143×97–108). Surface of subcapitulum papilliform. Eight pairs of subcapitular setae, a (26) setiform, smooth; m 1 (32), m 2 (12), m 3, m 5, h 1 and h 2 (21–23), m 4 (15), setiform, barbed bilaterally. Adoral setae smooth: or 1 (22) more or less triangular, wide in proximal part, blunt-ending; or 2 (29) and or 3 (26) long, setiform, blunt-ending. Palps (61) with setal formula 0-1-0-2-10 (+1ω). Chelicerae (162) with two setae, cha (9) short, thorn-like, chb (42) long, setiform and smooth.

Epimeral region ( Fig. 12 ). Epimeral plates distinct, with partly distinct ridges, epimeral setae setiform, setae 1a, 2a, 3a, 4a and one pair of lateral setae of epimere I smooth (6–10); other setae ciliate. Epimeral formula 10-6- 3-4.

Anogenital region ( Figs 12–13 ). Ten pairs of genital setae, setiform, four setae in outer row and six setae in inner row; seta g 7 (32) with short cilia, seta g 8 (31) smooth, others setae with short cilia (10–17). Two pairs of anal setae, setiform, barbed bilaterally (an, 60–65). Four pairs of adanal setae (ad, 78–82), setiform, barbed bilaterally. Lyrifissure iad distinct.

Legs ( Figs 17–20 ). Surface of legs covered with foveolae. All legs with one simple claw each with small basoventral tooth. Famulus ɛ conical and short. Solenidion ω1 on tarsus I, ω1 and ω2 on tarsus II, φ on tibia III thickened and blunt distally. Other solenidia setiform, with thinner tips. Formulae of leg setation and solenidia: I 0- 5-3(2) -4(1)-17(2), II 0-6-3(1)-4(1)-13(2), III 2-4 -2(1)-3(1)-12(0), IV 2-3 -2(1) -3(0)-10(0) (see Table 2).

Note: Roman letters for normal setae, Greek letters for solenidia, except ɛ for famulus, d σ and d φ–seta and solenidion coupled. Single prime (′) marks setae on anterior and double prime (″) setae on posterior side of the given leg segment. Parentheses refer to a pair of setae.

Material examined. Holotype, Mayang River (28°40’N, 108°20’E), Yanhe County, Guizhou Province, 16 Aug. 2014, leg. Zhiqiang Jang, in moss. One paratype, same data as holotype and four paratypes, Huaxi Reservoir (26°27’N, 106°36’E), Guiyang City, Guizhou Province, 18 Feb. 2017, leg. Guoru Ren, in soil.

Type deposited. The holotype and five paratypes are deposited in the Institute of Entomology, Guizhou University, Guiyang of China ( GUGC).

Etymology. The new specific name “ mammilatus ” is derived from the Latin “ mammillatus ”, and refers to the prodorsum and the whole surface of notogaster covered with bacilliar papillae.

Remarks. The new species Papillacarus (P.) mammilatus sp. nov. is morphologically most similar to Papillacarus (P.) angulatus (Wallwork, 1962) from Ethiopian and Southern Palaearctic (Caucasus, Iran), Neotropical ( Brazil) and Western Oriental regions ( India, Maharashtra). in having setiform prodorsal and notogastral setae and surface of body covered with bacilliar papillae. However, the new species differs from the latter by the following characterstics: (1) transverse bands S3 complete (versus S3 interrupted medially in P. angulatus ); (2) eight pairs of subcapitular setae (versus six pairs); (3) genital seta g 8 smooth, longer than g 9 (versus g 8 with short cilia, as long as g 9); (4) epimeral setal formula 10-6-3-4 (versus 9-4-3-4).

The new species Papillacarus (P.) mammilatus sp. nov. is morphologically also similar to Papillacarus (P.) echinatus ( Li, Li & Chen 1991) from China suroriental, Asia centrooccidental in having setiform prodorsal and notogastral setae and surface of body covered with bacilliar papillae. However, the new species differs from the latter by the following characterstics: (1) transverse bands S3 complete (versus S3 interrupted medially in P. echinatus ); (2) eight pairs of subcapitular setae, barbed bilaterally except a (versus six pairs, all smooth); (3) genital setae with short cilia except g 8 (versus all smooth); (4) epimeral setal formula 10-6-3-4 (versus 9-4-3-4).

Figures

FIGURE 11. Papillacarus (Papillacarus) mammillatus sp. nov., adult: dorsal view. SCale bar 100 µm.

FIGURE 12. Papillacarus (Papillacarus) mammillatus sp. nov., adult: ventral view. SCale bar 100 µm.

FIGURES 13–16. Papillacarus (Papillacarus) mammillatus sp. nov., adult: 13. lateral view; 14. CheliCera, right; 15. subCapitulum, ventral view; 16. palp, right. SCale bar 100 µm (13), 50 µm (14, 15), 25 µm (16).

FIGURES 17–18. Papillacarus (Papillacarus) mammillatus sp. nov., adult: legs, femur to tarsus, antiaXial view. 17. leg I, right; 18. leg II, left; SCale bar 50 µm.

FIGURES 19–20. Papillacarus (Papillacarus) mammillatus sp. nov., adult: legs, femur to tarsus, antiaXial view. 19. leg III, left; 20. leg IV, left. SCale bar 50 µm.