Tomocerus qixiaensis Yu, 2016

Yu, Daoyuan, Yao, Jin & Hu, Feng, 2016, Two new species of Tomocerus ocreatus complex (Collembola, Tomoceridae) from Nanjing, China, Zootaxa 4084 (1), pp. 125-134 : 130-133

Tomocerus qixiaensis Yu sp. nov.

Figs 1E–H , 4 , 5

Type material. Holotype female on slide. Collected in Qixia Mountain , Nanjing, Jiangsu Province, China, 118°57'22.2"E, 32°9'34''N, alt= 155m, 6.XII.2014, by Chunyan Qin & Daoyuan Yu (sample code NJ2014QX-2) . Paratypes 3 females on slides, 5 in alcohol, same data as holotype. Deposited in NJAU .

Description. Body length 3.3–4.3 mm. Ground colour of head and terga yellow, with unpigmented patches all over; ventral side of body white. Antenna purple all over except joints. Eye patches black, purple pigment circling antennal base and diffusely around clypeus and eye patch. Lateral side of Th. II, Th. III and Abd. I with relatively thin purple band. Legs purple except subcoxae and joints ( Fig. 1E ). Lateral flaps, anterior face and distal part of posterior face of ventral tube purple. Manubrium dorsally with two longitudinal purple bands along chaetal stripes ( Fig. 1F ), ventral side diffusely purple. Scales brown.

PAO not seen. Eyes 6+6. Antenna 0.6–0.7 times as long as body. Antenna length ratio as I:II:III:IV= 1.0: 1.4– 1.5: 8.5–9.3:0.7–0.8. Both dorsal and ventral sides of Ant. I and Ant. II scaled, base of Ant. III dorsally scaled, Ant. IV unscaled. Labral formula 4/5, 5, 4, distal edge of labrum with four curved papillae. Mandibular heads asymmetrical, left one with four teeth and right one with five, left molar plate distally with tapered tooth ( Fig. 4A ).

Basal teeth of maxillary lamella 5 prolonged, without beard-like appendage. Maxillary outer lobe with trifurcate palp, basal chaeta and four sublobal hairs. Both dorsal and ventral sides of head scaled. Cephalic dorsal macrochaetotaxy: anterior area: 2, 4; interocular area: 2, 7, with central chaeta; postocular area: 2+2; posterior area: 3+3. Posterior margin with about 30+30 small chaetae ( Fig. 4B ). Mentum with five chaetae, submentum with numerous chaetae.

Pattern of body chaetotaxy as Fig. 4C . Bothriotricha formula as 2, 1/ 0, 0, 1, 2, 0, 0. Th. II with dense macrochaetae along anterior margin and row of macrochaetae behind anterior margin. Number of macrochaetae or large mesochaetae in posterior row as 3, 3/ 3, 3, 4, 2, 4 (3 dorsal+1 lateral). Th. II with full set of central macrochaetae in "triangle" and additional smaller macrochaeta; antero-lateral macrochaeta present on Th. III; Abd.

III with two anterior macrochaetae; Abd. IV with antero-lateral macrochaeta; Abd. VI with numerous chaetae of moderate size. Most mesochaetae laterally and posteriorly on terga. Pseudopores near the middle line of terga, formula as 1, 1/ 1, 1, 1, 1, 0, 0; on Th. II pseudopore near posterior macrochaeta of central triangle.

Trochantero-femoral organ with 1, 1 slender chaetae ( Fig. 4D ). Front, middle and hind tibiotarsus ventrally with 5–6, 7–8, 7–8 strong spine-like chaetae, proximal 1–2 and distal 1–2 strong chaetae gradually narrowed towards apices and pointed, others subcylindrical, suddenly narrowed near apices, blunt or pointed ( Fig. 4E ). Tibiotarsal distal whorl with 11 chaetae, ventral six ordinary, dorsal five modified: tenent hair strong and clavate, as long as or slightly shorter than inner edge of unguis; two accessory chaetae small and slender, subequal to or longer than pretarsal chaetae; two guard chaetae thin and long. Unguis slender, with baso-internal ridging; lateral teeth pointed, of moderate size. Inner edge of unguis with 5–6 teeth, sub-basal tooth strongest, basal and distal teeth small. Unguiculus 0.5–0.6 times as long as unguis, inner edge with 0–1 small tooth. Pretarsus chaetae 1+1 ( Fig. 4F ).

Ventral tube with scales on both anterior and posterior faces, anterior face with about 30 chaetae on each side, posterior face with 110–120 chaetae, lateral flaps unscaled, each lateral flap with about 110 chaetae. Rami of tenaculum with 4+4 teeth, anterior face of corpus with about 25 chaetae, without scales ( Fig. 4G ). Ratio manubrium:dens:mucro=2.6–2.9: 3.6–3.7: 1.0. Manubrium ventrally scaled, without chaetae, laterally with large round scales and 11 chaetae, proximal chaetae thinner than distal ones, distal 7–8 chaetae spine-like; each dorsal chaetal stripe with about 250 chaetae of different sizes, with blunt prominent chaeta near center; file of dorsal scales along inner side of chaetal stripe, running about 0.33 length of manubrium from base; pseudopores 14–19 on each side ( Fig. 5A ); external corner chaeta as large as moderate sized mesochaetae in chaetal stripe ( Fig. 5B ). Dens basally with dorsal blunt prominent chaeta, without inner large modified scale or outer strong chaetae. Dental spines formula as 3–5/3–4, II, distal spine strongest ( Fig. 5C ); all spines with numerous small denticles ( Fig. 1G, H ). Dens dorsally with ordinary chaetae and feather-like chaetae, ventrally covered by scales. Mucro elongated and multi-setaceous; both basal teeth with proximal lamellae, outer tooth with toothlet; apical tooth slightly prolonged, subequal to or larger than subapical tooth; two dorsal lamellae running from subapical tooth, outer lamella with 4– 6 intermediate teeth, ending at inner basal tooth, inner lamella ending freely at base ( Fig. 5D ).

Etymology. Specific name derived from the type locality Qixia Mountain.

Ecology. In semi-decomposed litter of Liquidambar formosana and Pterocarya stenoptera .

Genebank accession number: KT246487 , KT246488 , KT246489 .

Remarks. The shape and arrangement of dental spines of Tomocerus qixiaensis sp. nov. are almost identical with those of the true T. ocreatus and T. qinae sp. nov., but the denticles on spines are smaller. Among the ocreatus complex, T. qixiaensis sp. nov. is more similar to T. folsomi in the short antenna, the colour pattern, the shape of claw and the small denticles on dental spines, but can be distinguished from the latter by the blunt prominent chaetae on manubrium, the dental spines formula and the smaller number of mucronal intermediate teeth. The body chaetotaxy of T. qixiaensis sp. nov. is almost identical with that of T. qinae sp. nov., including the possible variations on Th. II, but its cephalic chaetotaxy is different from that of the latter in having two additional lateral macrochaetae in the posterior area. The blunt prominent macrochaetae on manubrium and dens are also characteristic for T. qixiaensis sp. nov. Unlike the 2+2, 1 pattern in other species ( Yosii 1967), the new species has a 1+1, 1 pattern, with only two prominent chaetae in the middle of manubrium. Malformation is found in one specimen that the outer basal tooth on mucro is absent and the inner basal tooth is tripled, with membranes between each ( Fig. 5E ). A similar condition has been reported in Tritomurus falcifer Cassagnau, 1958 ( Cassagnau 1964) .

Figures

FIGURE 1. Tomocerus qinae sp. nov. & Tomocerus qixiaensis sp. nov. A – D, Tomocerus qinae sp. nov. (A) appearance in alcohol; (B) dorsal view of furca; (C) large dental spine; (D) small dental spines. E – H, Tomocerus qixiaensis sp. nov. (E) appearance in alcohol; (F) dorsal view of furca (arrows pointing to blunt prominent chaetae); (G) large dental spine; (H) small dental spines.

FIGURE 4. Tomocerus qixiaensis sp. nov. (A) mandibular head; (B) cephalic dorsal chaetotaxy; (C) body chaetotaxy; (D) trochantero-femoral organ; (E) tibiotarsi; (F) lateral view of hind claw; (G) tenaculum.

FIGURE 5. Tomocerus qixiaensis sp. nov. (A) dorsal view of right side of manubrium; (B) disto-external corner of manubrium; (C) dental spines; (D) normal mucro; (E) mucro with malformed basal teeth.