Lepidocyrtus fuscocephalus Mateos, 2022

Mateos, Eduardo & Álvarez-Presas, Marta, 2022, Integrative taxonomy reveals three new species of European Lepidocyrtus lignorum-group (Collembola, Entomobryidae), Zootaxa 5100 (4), pp. 451-481 : 457-463

Lepidocyrtus fuscocephalus Mateos sp. nov.

Figs 8–23 , Tabs 1–2

Zoobank: urn:lsid:zoobank.org:act:63B8C59B-4F13-45A9-A26B-3A71E784ADA4

Type material. Holotype: Male on two slides (CRBA-90744a (head) and CRBA-90744b(body)), Montnegre Natural Park , Sant Celoni, Barcelona ( Spain), 610 m above sea level, lat/long coordinates N41.66449 E2.56279, on soil litter under oak trees, hand collecting, 18.iv.2007, leg. E. Mateos. Paratypes: 8 specimens on slides (3 males, 1 female, and 4 without visible sexual plate) and 17 specimens preserved in absolute alcohol, same data as holotype . Holotype and paratype slides CRBA-90745a and CRBA-90745b 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 (lot LP125 ) .

Other material. 40 specimens preserved in absolute alcohol, Montnegre Natural Park , Sant Celoni, Barcelona ( Spain), 427 m above sea level, lat/long coordinates N41.6663 E2.5793, on soil litter under oak trees, 18.iv.2007, leg. E. Mateos. All material kept in the E. Mateos’ collection (lot LP134 ) .

Diagnosis. With dark blue pigment on all head, Ant.II–IV, coxae-trocanter-femur of legs I–III, and ventral tube; disperse blue pigment also on Abd.IV and Abd.V. Th.II slightly projecting over the head.Ant.I–III, legs, ventral tube and posterior region of manubrium with scales. Labial chaetotaxy M 1 M 2 REL 1 L 2, R shortened. Dorsal cephalic and body macrochaetae formula A 0 [A 2a]A 2 A 3 Pa 5 /00/0101+3. Abd.IV without chaeta s. Unguiculus lanceolate and with serrated outer margin.

Molecular diagnosis. This species includes all populations that cluster with CoxII and EF sequences of the individuals LP125-1 to LP125-5 ( Table 1 ), with significant support in an adequate molecular delimitation model.

Etymology. The species name refers to the dark blue colour of the head. In latin “fuscus” means dark, and “cephalus” means head.

Description. Holotype body length (without head nor furca) 2.2 mm, paratypes 1.8–2.2 mm. Body colour pattern ( Fig. 8 ) with dark blue pigment on all head, Ant.II–IV (with increasing colour intensity towards the distal part of each segment), coxae, and ventral tube; disperse blue pigment also on trochanter-femur of legs I–III, Abd.IV and Abd.V; densely black pigmented ocular areas. Mesothorax slightly projected over the head.

Antenna with scales on dorsal and ventral region of Ant.I–III. Ratio antenna:cephalic diagonal = 1.8–1.9 (head diagonal measured from cervical edge to apex of mouth part); ratio Ant.I:II:III:IV as 1:1.7:1.6:2.5. Basis of Ant.I dorsally with three microchaetae arranged in triangle (Ant.I-organ); apex of Ant.I with a short curved S-chaeta in the membranous area of the ventral region. Ant.III organ composed of two subcilindrical and curved sensory rods. Ant. IV without apical bulb. Eyes 8+8; eyes A to F of equal size, G and H slightly smaller, ratio A/G and A/H = 1.6.

Clypeus ( Fig. 9 ) with three prefrontal chaetae (1 pf0 and 2 pf1), four facial chaetae (f), and four lateral chaetae (2 L1 and 2 L2), all these chaetae ciliated. Prelabral and labral chaetae in typical number 4/554 ( Fig. 9 ), prelabral chaetae ciliated, all labral chaetae smooth and pointed, apical row curved; inverted U-shaped labral apical intrusion; four rounded labral papillae with a central small pointed expansion. Maxillary palp outer lobe with smooth apical appendage and basal chaeta, and three smooth sublobal appendages ( Fig. 10 ). Lateral process of outer labial papilla finger-shape, slightly curved, tip not reaching apex of papilla ( Fig. 11 ).

Labial and postlabial chaetotaxy as in Fig. 12 ; with five smooth proximal chaetae at the base of labial palp; labial anterior row formed by five smooth chaetae (a1–a5); posterior row formed by ciliated chaetae with formula M 1 M 2 REL 1 L 2; chaeta R shorter, ratio M 2 /R ≈ 2.4; one paratype with a supernumerary reduced M chaeta (as long as chaeta R) between M 1 and M 2 present on one side ( Fig. 12 ); postlabial chaetaxy with all chaetae ciliated, row I (along ventral cephalic groove) with 4 chaetae.

Dorsal cephalic macrochaetae formula A 0 A 2 A 3 Pa 5, but also with pair of smaller supplementary macrochaetae A 2a between A 0 and A 2; maximum number of macrochaetae An on head 15+15. Interocular chaetotaxy with s, t, p ciliated chaetae and 5–7 scales ( Fig. 13 ).

Dorsal body macrochaetae formula 00/0101+3 (macrochaetae m3 on Abd.II, and Sm+B4, B5, B6 on Abd.IV). Dorsal chaetotaxy of Th.II–III and Abd.I as in Figs 14–16 . Th.II with 2 lateral S-chaetae (al and ms) and without macrochaetae in dorsal position. Th.III with a lateral sensillum (al) close to several ciliated chaetae. Abd.I with a lateral S-microchaeta (ms) external to a6. Chaetotaxy of Abd.II–III as in Figs 17–18 . Abd.II chaeta ml present or absent depending on the specimens; macrochaeta m3 with socket diameter 1.6 times higher than macrochaeta m5. Abd. III chaeta mi present or absent depending on the specimens, with chaeta d3 between macrochaetae pm6 and p6, and with S-chaetae as and ms. All chaetae associated with the trichobothria on Abd.II–III strongly ciliate and partially fan-shaped. Chaetotaxy of Abd.IV as in Fig. 19 ; macrochaetae Sm, B4, B5, B6, D3, E2, E3, E4, F1, F2, F3 broader and with broad socket; macrochaetae T6, T7, D2, De3, E1, E4p, Fe4, Fe5, F3p shorter or longer but always thinner and with socket of minor diameter; macrochaeta F2 inserted above macrochaeta E3; the ratio of distances between macrochaetae Sm–B4 / B4–B6 is 0.8–0.9; the ratio of distances between macrochaetae B4–B5 / B5–B6 is 1.1–1.3; accessory chaeta s associated with trichobotrium T2 absent; chaetae D1, m, pe and pi associated with trichobotria T2 and T4 fan-shaped and strongly ciliate, chaeta a pointed and strongly ciliate; sens chaetotaxy composed of 2 anterior dorsomedial elongate S -chaetae, and short chaetae as and ps; posterior margin with 9+9 smooth mesochaetae; lateral region BP4 without pseudopori. Dorsal chaetotaxy of Abd.V with S-chaetae as, acc.p4 and acc.p5 ( Fig. 20 ).

Legs with scales except in claws. Rectangular-shaped trochanteral organ formed by a maximum of 28 smooth straight chaetae ( Fig. 21 ). Unguis ( Fig. 22 ) with basal pair of teeth at 49% from base of the inner edge, and with two inner unpaired teeth at 71% and 88% from the base of the inner edge respectively; on unguis I–II the apical inner tooth tiny and sometimes difficult to see; one external tooth and a pair of lateral teeth also present. Unguiculus lanceolate with serrated outer margin (serration less evident on unguiculus III). Tibiotarsal tenent hair spatulate, smooth and as long as claw; ratio of supra-empodial chaeta (smooth chaeta on tibiotarsus III opposite to tenent hair) / unguiculus ≈ 1.2.

Ventral tube with 6+6 ciliated chaetae on anterior side (4+4 proximal and 2+2 distal) and 11+11 weakly ciliated chaetae on posterior side; scales present on anterior and posterior sides; lateral flap with a maximum of 26 laterodistal chaetae (20–23 ciliated and 3 smooth).

Manubrium with scales on anterior and posterior surfaces, with 2+2 ciliated apical chaetae on anterior side. The ratio manubrium:dens:mucro is 19:20:1. Manubrial plate with 3–4 inner chaetae and a maximum of 16 outer chaetae. Dental tubercle absent. Mucro with the two teeth of the same size, without spinelet on basal spine.

Pseudopores distribution on dorsal and ventral positions as in Figs 23a–b .

Ecology and distribution. All specimens were obtained by sifting soil surface litter under oak trees.

Discussion. Morphological characters clearly assign Lepidocyrtus fuscocephalus sp. nov. to the Lepidocyrtus lignorum -group (sensu Mateos 2011). By the characteristic body colour pattern L. fuscocephalus sp. nov. clearly differs from all the other species of the L. lignorum -group. Other differences between all species included in the group are summarized in Table 2 . By having body partially blue pigmented and lanceolate unguiculus L. fuscocephalus sp. nov. is close to species L. instratus , L. labyrinthi , L. traseri , L. milagrosae sp. nov. and L. semicoloratus sp. nov. Of these, the new species differ by the colour pattern, the presence of scales on Ant.III and pointed labral apical chaetae.

Figures

FIGURE 8. Lepidocyrtus fuscocephalus sp. nov.: Habitus lateral (specimen in alcohol, without scales).

FIGURES 9–12. Lepidocyrtus fuscocephalus sp. nov.: 9, clypeal and labral chaetotaxy; 10, maxillary palp (right side); 11, outer labial papilla (right side); 12, labial and postlabial chaetotaxy (the arrow points to a supernumerary M chaeta present in one paratype). Black dots––ciliated chaetae, cross––scales, p.c.—proximal chaetae of labial palp.

FIGURE 13. Lepidocyrtus fuscocephalus sp. nov.: Dorsal head chaetotaxy (left side). Broad circles––long ciliated macrochaetae, small circles––short ciliated macrochaetae.

FIGURES 14–16. Lepidocyrtus fuscocephalus sp. nov. dorsal chaetotaxy (left side): 14, Th.II; 15, Th.III; 16 Abd.I. Circles–ciliated chaetae.

FIGURES 17–18. Lepidocyrtus fuscocephalus sp. nov. dorsal chaetotaxy (left side): 17, Abd.II; 18, Abd.III. Broad circles–broad ciliated macrochaetae, small circles––thin ciliated macrochaetae.

FIGURE 19. Lepidocyrtus fuscocephalus sp. nov.: Abd.IV chaetotaxy (left side). Broad black circles––broad ciliated macrochaetae, small black circles––thin ciliated macrochaetae.

FIGURES 20–22. Lepidocyrtus fuscocephalus sp. nov.: 20, Abd.V chaetotaxy (left side), broad circles––long ciliated chaetae, small circles––short ciliated or smooth chaetae; 21, trochanteral organ; 22, third leg unguis and unguiculus.

FIGURE 23. Lepidocyrtus fuscocephalus sp. nov, L. milagrosae sp. nov. and L. semicoloratus sp. nov.: Pseudopores distribution: a, dorsal pseudopores; b–c, ventral pesudopores.