Lepidocyrtus pulchellus Denis, 1926

Mateos, Eduardo, 2020, European Lepidocyrtus lignorum-group, new findings and redescritpion of Lepidocyrtus pulchellus Denis, 1926 (Collembola, Entomobryidae), Zootaxa 4790 (3), pp. 564-576 : 566-568

Lepidocyrtus pulchellus Denis, 1926

Figs 1–17 , Table 1

Material examined. Two specimens (of indeterminate sex) on two slides from the type locality ( Campigna , Italy, 1000 m above sea level) deposited at the MNHN Paris ( France), J. R . Denis det., M.P. Zangheri leg., 01.vii.1924. Two specimens (of indeterminate sex) on one slide from Bertinoro ( Italy, 250 m a.s.l.) deposited at the MNHN Paris ( France), J. R . Denis det., M.P. Zangheri leg, 31.x.1926. One male on slide from Monte Cimino, Viterbo municipality, Lazio province ( Italy, 1014 m a.s.l.), position N42°24’33.9” E12°12’14.3”, E. Mateos leg., 04.v.2014, sample code LP521 . Six specimens (4 females and 2 with indeterminate sex) on six slides and eleven specimens on absolute alcohol form Rapallo , Varese Ligure municipality, La Spezia province ( Italy, 680 m a.s.l.), position N44°22’48.53 E9°30’40.63”, B. Zhang leg., 04.v.2015, sample code LP389 .

Diagnosis. Body colour yellow with a characteristic dark blue design: A wide transverse dark blue band in abd. II, abd.III, and most of abd.IV. Th.II slightly projecting over head. Ant.I–III, legs, ventral tube and posterior region of manubrium with scales. Apical bulb on ant.IV absent. Labial chaetae M 1 M 2 REL 1 L 2 in “p row” well developed and ciliated, R shortened. Dorsal cephalic and body macrochaetae formula as A 0 [A 2a]A 2 A 3 Pa 5 /00/0101+3. Without chaeta s on abd.IV. Unguiculi truncate, with serrate outer edge.

Redescription. Body length 1.5–1.7 mm. Specimens from the slides of MNHN and all new collected specimens showed a very characteristic colour pattern ( Fig. 2 ): a wide dark blue (almost black) transverse band in abd. II–abd.III and most of abd.IV, tips of ant.II–IV and coxae. Ocular areas dark pigmented. Th.II slightly projecting over the head. Scales densely covering dorsal and ventral surfaces of head, trunk, legs, ventral tube and manubrium, dorsal surface of ant.I–III, and anterior surface of dens.

Antennal length to head diagonal length ratio (head diagonal measured from cervical edge to apex of mouth part) 1.6–1.9. Relation of antennal joints I–IV as 1:1.9:1.8:2.8. Ant.I with three dorsolateral small acute chaetae in a triangle (ant.I-organ sensu Hüther, 1986). Ant.III sense organ composed of two bent sensory rods partially behind a cuticular fold ( Fig. 3 ). Ant. IV without apical bulb.

Arrangement of chaetae on labrum 4/554, prelabral chaetae ciliated, first and second row of labral chaetae smooth, apical row bi-branched (detail in Fig. 4 ). Labrum intrusion inverted U-shaped, labral edge with four minute rounded labral papillae with two/three-pointed end ( Fig. 4 ). Labial palp with lateral process on papilla E slightly curved, with pointed apical end and not reaching apex of papilla ( Fig. 5 ). Outer maxillary palp with two smooth chaetae and three smooth sublobal chaetae ( Fig. 6 ).

Labium chaetotaxy formed by 5 smooth chaetae (a1–a5) in anterior row; basal row with ciliated chaetae M 1 M 2 REL 1 L 2, with R smaller than other chaetae (ratio of R/M ≈0.4), some specimens with three M chaetae on one side of the labium. Postlabial chaetotaxy with 4+4 ciliated chaetae along ventral cephalic grove ( Fig. 7 ).

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 13+13. Eye patches dark blue. Diameters of eyes A–F about the same. Eyes G and H slightly smaller (A:G; A:H ≈ 1.6). Interocular chaetotaxy with s, t, p chaetae and 3–4 intraocular scales ( Fig. 8 ).

Dorsal body macrochaetae formula 00/0101+3 (macrochaetae m3 on abd.II, and C1+B4, B5, B6 on abd.IV). Dorsal chaetotaxy of th.II–III and abd.I as in Figs 9–11 . 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 12–13 . Abd.II without chaeta a2p; chaeta ml (associated with trichobothrium m2) absent in several specimens; macrochaeta m3 with socket diameter 1.5 times higher than macrochaeta m5. Abd.III with S-chaetae as and ms, and chaeta d3 between macrochaetae pm6 and p6; two specimens from sample LP389 with lateral tuft of 10+10 long ciliated filiform chaetae. Chaetae associated with trichobotria on abd.II–III pointed, thickened in the center and ciliated, only chaeta am6 on abd.III has fan-shaped morphology. Chaetotaxy of abd.IV as in Fig. 14 ; macrochaetae B4, B5, B6, C1, D3, De3, E2, E3, E4, F1, F2 and F3 broader with broad socket, while D2, D3p, E1, E4p, E4p2, F3p, Fe4, Fe5, r3, T6 and T7 thinner with smaller socket; macrochaeta F2 above macrochaeta E3; the ratio of distances between macrochaetae C1–B4 / B4–B6 is 0.68–0.98; the ratio of distances between macrochaetae B4–B5 / B5–B6 is ≈ 1; accessory chaeta s associated with trichobotrium T2 absent; chaetae a, m, pe, pi associated with trichobotria T2 and T4 fan-shaped; chaeta D1 pointed, thickened in the center and ciliated; sens chaetotaxy composed by 3 anterior dorsomedial elongate S -chaetae, and short chaetae as and ps. Dorsal chaetotaxy of abd.V with S-chaetae as, acc.p4 and acc.p5 ( Fig. 15 ).

Trochanteral organ with a maximum of 30 smooth spiny chaetae forming a rectangular shape pattern. Ungues ( Fig. 16 ) with paired basal teeth at 45–50% from inner edge, one median tooth at 64–68%, and a tiny apical tooth at 83–87% from inner edge, respectively; one external tooth and a pair of lateral teeth also present; ungui.I–III truncate and with serrate outer edge; tibiotarsal tenent hair spatulate, smooth and as long as claw; ratio of supraempodial chaeta (smooth chaeta on tibiotarsus III opposite to tenent hair) / unguiculus is ≈ 0.8.

Ventral tube with 5+5 ciliated chaetae on anterior side and 12+12 weakly ciliated chaetae on posterior side; lateral flap with 17 laterodistal chaetae (13 ciliated and 4 smooth).

Manubrium with 2+2 ciliated apical chaetae on anterior side; manubrial plate with 3–4 inner chaetae and 8–11 chaetae outer to the 2 pseudopores. Dental tubercle absent. Mucro without spinelet on basal spine. Ratio manubrium/dens/mucro as 15:18:1.

Ecology and distribution. The only information provided by Denis (1926, 1927) was that the specimens were collected from the soil at Campigna locality and at an altitude of 1000 m above sea level. The specimens deposited at the NMNH (Paris) do not have information related to the collection site, and the only information available is the altitude (250 m) at which Bertinoro municipality is located. Specimens from Rapallo locality (680 m altitude) were collected form oak forest litter layer, and specimens from Viterbo locality (1014 m altitude) were collected from beech forest litter layer.

Figures

FIGURE 1. Lepidocyrtus pulchellus, map of Italy showing the four localities were the species has been found. 1, Campigna (Type locality); 2, Bertinoro; 3, Viterbo; 4, Rapallo.

FIGURE 2. Lepidocyrtus pulchellus, habitus lateral. A and B specimens from the type locality (Campigna, see « Material examined »); C and D specimens from Bertinoro (see « Material examined »); E specimen from Viterbo (sample LP521), scale bar = 1 mm.

FIGURES 3–7. Lepidocyrtus pulchellus. 3, ant.III apical organ; 4, labrum; 5, outer labial papilla; 6, maxillary palp; 7, labial and postlabial chaetotaxy.

FIGURE 8. Lepidocyrtus pulchellus, dorsal head chaetotaxy (left side).

FIGURES 9–11. Lepidocyrtus pulchellus. 9, th.II dorsal chaetotaxy (left side), psp—pseudoporus, circles—ciliated chaetae; 10, th.III dorsal chaetotaxy (left side), psp—pseudoporus; 11, abd.I dorsal chaetotaxy (left side), psp—pseudoporus.

FIGURES 12–13. Lepidocyrtus pulchellus. 12, abd.II chaetotaxy (left side), black circles—broad ciliated macrochaetae, psppseudoporus; 13, abd.III chaetotaxy (left side), broad black circles—broad ciliated macrochaetae, small black circles—thin ciliated macrochaetae, psp—pseudoporus.

FIGURE 14. Lepidocyrtus pulchellus, abd.IV chaetotaxy, broad black circles—broad ciliated macrochaetae, small black circles—thin ciliated macrochaetae, psp—pseudoporus.

FIGURES 15–16. Lepidocyrtus pulchellus. 15, abd.V chaetotaxy, broad black circles—long ciliated macrochaetae, small black circles—short ciliated macrochaetae or smooth mesochaetae; 16, third leg apex with unguis, unguiculus and tenent hair.

FIGURE 17. Lepidocyrtus lignorum-group, lateral habitus of all European species currently included in the group. On the left side of the figure, species without body pigmentation are represented, in the center species with pigment forming dots or bands, on the right side species with pigment spread on the thorax and abdomen (above—less pigmented species, below—more pigmented species). Image of L. vexillosus extracted from http://v3.boldsystems.org/index.php/Taxbrowser_Taxonpage?taxid=398041. Image of L. instratus extracted from Handschin (1924). The image of L. pulchellus correspond to one specimen of sample LP389 (from Rapallo, Italy).