Lepidocyrtus divisus , Mateos, 2025

Mateos, Eduardo & Zhang, Bing, 2025, New species of the European Lepidocyrtus curvicollis-group (Collembola: Entomobryidae), Zootaxa 5717 (3), pp. 403-418 : 405-416

Lepidocyrtus divisus, Mateos , sp. nov.

urn:lsid:zoobank.org:act:

Figs 2–23 , Tabs 1–2

Type material. Holotype: Female on slide code CRBA-113472, Cassine, Piemonte ( Italy), 200 m a.s.l., lat/long coordinates N44.76891 E8.49129 ( Fig. 1 location 1), collected in grassland surrounded by forests using a modified leaf blower functioning as an aspirator (diameter of opening 14 cm), 07.v.2015, leg. B. Zhang. Paratypes: 5 specimens on slides ( 1 female and 4 adults without visible genital plate) and 9 specimens preserved in absolute alcohol, same data as holotype . Holotype and paratype female slide code CRBA-113473 saved in the collection of the Centre de Recursos de Biodiversitat Animal , Faculty of Biology , University of Barcelona (http://www.crba.ub.edu); other paratypes kept in the E. Mateos’ collection ( University of Barcelona, lot LP415 ) .

Other material. Three specimens on slides, Vernante , Piemonte ( Italy), 1175 m a.s.l., lat/long coordinates N44.20194 E7.50488 ( Fig. 1 location 2), collected in grassland surrounded by forests using a modified leaf blower functioning as an aspirator (diameter of opening 14 cm), 07.v.2015, leg. B. Zhang, lot LP416 . 2 specimens on slides, Pedavena , Veneto ( Italy), 925 m a.s.l., lat/long coordinates N46.04116 E11.84655 ( Fig. 1 location 3), collected in grassland surrounded by forests using a modified leaf blower functioning as an aspirator (diameter of opening 14 cm), 04.v.2015, leg. B. Zhang, lot LP413 . 5 specimens on slides and 5 specimens preserved in absolute alcohol, Orsomarso , Calabria ( Italy), 162 m a.s.l., lat/long coordinates N39.79414 E15.92726 ( Fig.1 location 4), hand collected under logs and stones in forest environment, 21.iv.2017, leg. E. Mateos, lot LP481 . 7 specimens on slides and 9 specimens preserved in absolute alcohol, Roybon , Dep. Isère, Region Ródano-Alpes ( France), 652 m a.s.l., lat/long coordinates N45.241130 E5.282241 ( Fig.1 location 5), hand collected under logs and stones in forest environment, 02.xi.2012, leg. E. Mateos, lot LP315 . All other material kept in the E. Mateos’ collection ( University of Barcelona) .

Diagnosis. Body length (without head nor furca) 2–3 mm ( Holotype 2.6). With dark purple pigment on ant. II–IV and coxae I–II, head with lateral and ventral light purple pigment, legs beyond coxae purple. Mesothorax projecting over head. Scales covering ant.I–IV, legs, ventral tube, and posterior face of manubrium. One pseudopore at the ventral apical end of ant.I. Ocular chaeta q present. Prelabral chaetae smooth. Labial chaetotaxy M 1m 2Rel1l2, M1 and R shortened. Dorsal cephalic macrochaetae formula A0[A2a]A2Pa5; dorsal body macrochaetae formula 0,0/0,1,0,1+3; lateral body macrochaetae formula 0,0/0,1,4,16. Fourth abdominal segment with chaeta s. With two short ciliated postlabial chaetae ( X and X’). Unguis with basal paired teeth and one unpaired tooth. Unguiculus lanceolate and with smooth or finely serrated outer margin. Lateral pseudopores present on abd.III–IV; abd.IV also with ventral pseudopores located on basal region. Dorsal pseudopores of th.II and abd.IV divided.

Etymology. The species name refers to the presence of divided pseudopores.

Description. Holotype body length (without head nor furca) 2.6 mm, paratypes 2.0–3.0 mm. Body color pattern ( Fig. 2 ) with dark purple pigment on ant.II–IV and coxae I–II, head with lateral and ventral light purple pigment, legs beyond coxae purple, densely black pigmented ocular areas. Mesothorax projected over head.

HEAD. Dorsal cephalic macrochaetae A0, A2, Pa5, with pair of smaller supplementary macrochaetae A2a between A0 and A2 (reduced formula= A0[A2a]A2Pa5); maximum number of macrochaetae An on head 22+22 ( Fig. 3 ). Interocular chaetotaxy with s, t, p, q ciliated chaetae and 2 scales.Eyes 8+8; eyes A to F subequal, G and H slightly smaller, ratio F/G and C/H ≈ 1.7 ( Fig. 4 ).

Clypeus ( Fig. 5 ) prefrontal area with three chaetae (1 pf0 and 2 pf1) and eight scales, facial area with two chaetae ( f) and three scales, lateral area with 1+1 L1 and 1+1 L2 chaetae; all these chaetae and scales ciliated.

Labrum ( Fig. 6 ) with 5/5/4 smooth and pointed chaetae on rows p/m/a, respectively; two rounded labral papillae with pointed apex; four prelabral chaetae ( pl) smooth and pointed.

Maxillary palp outer lobe ( Fig. 7 ) with apical appendage and basal chaeta smooth and equal in size, sublobal plate with three smooth chaeta-like appendages.

Labial and postlabial chaetotaxy as in Fig. 8 ; with five smooth proximal chaetae at the base of labial palp; labial anterior row with five smooth chaetae ( a1–a5); posterior row with m2, e, l1 and l2 smooth and M1 and R ciliated, reduced formula M 1m 2Rel1l2 ( one paratype with one ciliated chaeta M1 and one smooth chaeta m1, another paratype with ciliated chaeta E); chaetae m2 e l1 and l2 smooth, chaetae M1 and R ciliated and shorter, ratio m2/ M1 = 3.6, ratio m2/ R = 3.2; postlabial chaetotaxy with all chaetae ciliated, with four chaetae along ventral cephalic groove, and with two X chaetae ( X and X’) shorter, ratio G3/X = 2.8. Lateral process of outer labial papilla fingershape, slightly curved and reaching apex of papilla ( Fig. 9 ) .

BODY. Dorsal macrochaetae formula 00/0101+3, lateral macrochaetae formula 0,0/0,1,4,16. Dorsal chaetotaxy of th.II–III as in Figs 10–11 . Mesothorax polychaetotic, covered by numerous small smooth microchaetae interspersed among scales, with 2 lateral S-chaetae ( al and ms), without dorsal nor lateral macrochaetae. Metathorax with a lateral sensillum ( al) close to several ciliated chaetae, without dorsal nor lateral macrochaetae. Chaetotaxy of abd.I– III as in Figs 12–14 . Abd.I with a lateral S-microchaeta ( ms) external to a6, without dorsal nor lateral macrochaetae. Second abdominal segment with dorsal macrochaeta m3 (lsM) and lateral macrochaeta m5 (lsM); m3 socket 1.5 times larger than m5 socket. Third abdominal segment with lateral macrochaetae pm6 and p6 (lsM both), with chaeta d3 between these two macrochaetae, with lateral macrochaetae a8 and p8 (ssM both), and with S-chaetae as and ms. All chaetae associated with the trichobothria on abd.II–III fan-shaped ( Figs 13–14 ). Chaetotaxy of abd. IV as in Fig. 15 ; dorsal macrochaetae Sm, B4, B5, B6, and lateral macrochaetae D3, E2, E3, E4, F1, F2, F3 with large socket (lsM); lateral macrochaetae T6, T7, D2, D3p, De3, E1, E4p, Fe4, Fe5 longer or shorter but always with small socket (ssM); macrochaeta F2 inserted at the same level of macrochaeta E3; the ratio of distances between macrochaetae Sm–B4 / B4–B6 as 0.35–0.43; ratio of distances between macrochaetae B4–B5 / B5–B6 as 1.0–1.2; accessory chaeta s associated with trichobothrium T2 present; chaetae a, D1, m, s, pe and pi associated with trichobothria T2 and T4 fan-shaped; sens chaetotaxy composed of three anterior dorsomedial elongate S-chaetae, and short chaetae as and ps.; posterior margin with 9+9 smooth mesochaetae; with 8–19 pseudopores located externally to the lateral suture and 4–8 in the ventral region; BP4 without pseudopores. Dorsal chaetotaxy of abd.V ( Fig. 16 ) with S-chaetae as, acc.p4 and acc.p5.

APPENDAGES. Antennal segments I–III and basal portion of ant.IV with scales on dorsal and ventral faces ( Fig. 17 ). Ratio antenna:cephalic diagonal ≈ 1.9 (head diagonal measured from cervical edge to apex of mouth part); ratio ant.I:II:III:IV as 1:1.9:1.8:3.9. Proximal margin of ant.I dorsally with three microchaetae arranged in triangle (ant.I-organ); ventro-distal membranous margin of ant.I with a short-curved S-chaeta. Ant.III organ composed of two subcylindrical, slightly curved sensory rods of equal length. Ant.IV without apical bulb.

All legs segments with scales. Trochanteral organ with about 60 spine-like chaetae, 9 on posterior arm, 10 on ventral arm, 34 internal, 6 external and 1 apical ( Fig. 18 ). Unguis on all legs ( Fig. 19 ) with basal pair of teeth at 47% from base of inner edge and with one unpaired tooth at 69% from base of inner edge; one external tooth and a pair of lateral teeth also present. Unguiculus lanceolate with smooth or finely serrated outer margin. Tenent hair spatulate, smooth and a little longer than claw (ratio tenent hair/claw ≈ 1.1); ratio of supra-empodial chaeta (smooth chaeta on tibiotarsus III opposite to tenent hair)/unguiculus ≈ 1.5.

Ventral tube with 11+11 ciliated chaetae on anterior side ( Fig. 20 ) and 9+9 ciliated chaetae on posterior side; scales present on anterior and posterior sides; lateral flaps with a maximum of 45 laterodistal chaetae (38 ciliated and 7 smooth).

Manubrium with scales on anterior and posterior surfaces, with 2+2 ciliated apical chaetae on anterior side. Ratio manubrium:dens:mucro as 17:17:1. Manubrial plate ( Fig. 21 ) with two pseudopores, three inner chaetae, and a maximum of 30 outer chaetae. Dental tubercle absent. Mucro with two subequal teeth, basal spine smooth (without spinelet).

PSEUDOPORES. Pseudopores distribution on dorsal, lateral and ventral regions of head, body, and appendages as in Fig. 22 and Table 1. The dorsal pseudopores of th.II and abd.IV are divided in all the specimens studied, in the other segments, dorsal pseudopores may or may not be divided depending on the specimen. The antennal, coxal, furcal, and body ventral pseudopores, with few exceptions, are not divided. Divided pseudopores may be formed by two, three or four subunits, and some undivided pseudopores have an elongated shape ( Fig. 23 ).

Ecology and distribution. The specimens were hand collected under logs and stones in forests and small grasslands surrounded by forest. The new species is only known from the localities indicated in the description.

Discussion. There are two different published nomenclatures that code for postlabial chaetae in Entomobryidae, Chen & Christiansen (1993) and Soto-Adames (2010). According to Soto-Adames (2010), the short ciliated chaetae X and X’ that we have observed in L. divisus sp nov. correspond to O1 and L2 respectively, while in the scheme of Chen & Christiansen (1993,) the O1 chaeta is X, and the L2 chaeta has no equivalent and is named X’ in the present paper ( Fig. 8 ).

*pse always divided; + pse divided or not divided depending on the specimens; (#) group of pse in central position of the tergum.

The new species belongs to the L. curvicollis -group by the following characters ( Mateos & Petersen 2012): presence of scales on the antennae, legs and dorsal side of manubrium; mesothorax protruded over the head; labial chaeta M1 shorter than M2; presence of chaeta s on abd.IV; dorsal macrochaetae formula A0A2Pa5/00/0101+3. The best diagnostic character of the Lepidocyrtus divisus sp. nov. is the presence of divided pseudopores in the dorsomedial position of some tergites. This character differentiates the new species from all other species of the L. curvicollis -group. Another three important diagnostic characters of the new species are:

1—Presence of smooth chaetae at the base of the labium. Within the L. curvicollis -group the only species described so far with smooth labial chaetae is L. curvicollis , and it is differentiated from the new species by presenting many dorsal pseudopores in abd.IV and not presenting lateral or ventral pseudopores in this segment.

2—Presence of pseudopores on abd.IV located externally to the lateral suture. Within the L. curvicollis -group, L. mariani Traser & Danyi, 2008 is the only species described so far with lateral pseudopores in abd.IV and it is differentiated from the new species by also having lateral pseudopores from th.III to abd.III, and for having all chaeta at base of labium ciliated (although not typical, occasionally also L. mariani can have smooth labial chaetae m1, r, l1 and l2, see Winkler & Mateos 2018).

3—Presence of ventral pseudopores in abd.IV located at the base of the inner edge of BP4. The presence of ventral pseudopores in abd.IV is observed in four species of the L. curvicollis -group, but in different positions depending on the species. In L. flexicollis these pseudopores are distributed forming a line along the inner edge of BP4 (see Mateos et al. 2021 Fig.S3 ), while in the species L. divisus sp. nov, L. mariani and L. montseniensis these pseudopores are located grouped at the base of the inner edge of BP4 ( Fig. 21B ).

Other characters that differentiate the new species from the rest of the species of the L. curvicollis -group are indicated in Table 2.

Figures

FIGURE 1. Situation of the five localities (red dots) where the specimens of Lepidocyrtus divisus sp. nov. were obtained.

FIGURE 2. Lepidocyrtus divisus sp. nov. Lateral view of the holotype (above) and a paratype (below).

FIGURES 3–4. Lepidocyrtus divisus sp. nov.: 3, Dorsal head chaetotaxy (left side); 4. Ocular area. Broad black circles—long ciliated macrochaetae, small black circles—short ciliated macrochaetae, empty circles—scale sockets.

FIGURES 5–9. 5–7. Lepidocyrtus divisus sp. nov.: 5, clypeal chaetotaxy; 6, labral chaetotaxy; 7, maxillary palp, aa—apical appendage, bc—basal chaeta, slp—sublobal plate. 8–9. Lepidocyrtus divisus sp. nov.: 8, labial and postlabial chaetotaxy, p.c.— proximal chaetae of labial palp. 9, outer labial papilla lp—lateral process.

FIGURES 10–11. Lepidocyrtus divisus sp. nov. dorsal chaetotaxy (left side): 10, Th.II; 11, Th.III. Empty circles—ciliated chaetae, crossed circles—pseudopores.

FIGURES 12–14. Lepidocyrtus divisus sp. nov. dorsal chaetotaxy (left side): 12, Abd.I; 13, Abd.II; 14, Abd.III. Black circles— ciliated macrochaetae, crossed circles—pseudopores.

FIGURES 15–16. Lepidocyrtus divisus sp. nov.: 15, Abd.IV chaetotaxy (left side), broad black circles—ciliated macrochaetae with large socket, small black circles—ciliated macrochaetae with small socket; 16, Abd.V chaetotaxy (left side), black circles— ciliated chaetae with length proportional to diameter socket.

FIGURES 17–21. Lepidocyrtus divisus sp. nov.: 17, dorsal view of head and antennae showing the scale covering (17B);18, trochanteral organ, ac—apical chaeta, ext—external chaetae, post—posterior arm, vent—ventral arm; 19, third leg unguis and unguiculus; 20, anterior (ant) an posterior (post) faces of ventral tube; 21, manubrial plate (left side), circles—ciliated chaetae with length proportional to diameter socket, crossed circles—pseudopores.

FIGURE 22. Lepidocyrtus divisus sp. nov.: Pseudopores distribution on dorsal (A) and ventral (B) surfaces.

FIGURE 23. Lepidocyrtus divisus sp. nov.: Different pseudopores morphology present on the dorsal surface of the body.