Lepidocyrtus (Setogaster) nigrofasciatus Womersley, 1934

Mateos, Eduardo & Greenslade, Penelope, 2015, Towards understanding Lepidocyrtus Bourlet, 1839 (Collembola, Entomobryidae) I: diagnosis of the subgenus Setogaster, new records and redescriptions of species, Zootaxa 4044 (1), pp. 105-129 : 109-112

Lepidocyrtus (Setogaster) nigrofasciatus Womersley, 1934 comb. nov.

Figs 1–2 , 9–33 , 49 , Tabs 2–3

Material examined. Holotype, ( SAM I22550), SOUTH AUSTRALIA, Mt Osmond, 34.9584S 138.66637E, in moss, 6.vi.1934, H. Womersley; two ‘cotypes’ ( SAM I22552-a, I22552-b), VICTORIA, Kalorama, Mt. Dandenong, 37.833878S 145.368247E, 17.v.1932, J.W. Rath; two paratypes ( SAM I22551 and I22554), same data as holotype. All slides deposited at SAM.

Other material. Three specimens, VICTORIA, Yarra Ranges National Park, 37.50687S 145.77692E, The Beeches, Lady Talbot Drive, in moss, 15.v.2009, G. Perdomo (sample LP309); three specimens, SOUTH AUSTRALIA, Mt Bold, 35.120206S 138.705340E, 4.v.1975, P. Greenslade (sample LP323); two specimens, Belair National Park, Mt Lofty Ranges, 35.00063S 138.64327E, 309 m asl, 29.vii.2014, P. Greenslade (sample LP378). All specimens deposited at University of Barcelona.

Description. Adult body length (without head and furca) 0.7–1.0 mm. Mesothorax not projecting over head. Body dorsoventrally compressed with dark blue pigment present on th.II to abd.III, dispersed spots on dorsal and ventral head, ant.I–IV, and on coxae and trochanters of three pair of legs ( Fig. 1 ); several specimens with diffuse pigment (or absent) from th.II to abd.II ( Fig. 2 ); densely black pigmented ocular areas.

Antenna without scales. Basis of ant.I dorsally and ventrally with three microchaetae arranged in triangle ( Fig. 9 ). Ant.III organ composed of two subcylindrical sensory rods partially covered by integumentary fold ( Fig. 10 ). Ant.IV with subapical chaeta of mushroom-shaped named here “T-chaeta” ( Fig. 11 ); without apical bulb.

Ciliated prelabral chaetae and smooth labral chaetae in typical number 4/5,5,4; chaetae of apical row thicker than those in other rows. Closed inverted V-shaped labral apical intrusion; labral papillae smooth ( Fig. 12 ). Lateral process ( sensu Fjellberg 1999 ) of outer labial papilla short, tip not reaching apex of papilla ( Fig. 13 ). Maxillary palp outer lobe with two subequal smooth chaetae and three smooth sublobal appendages ( Fig. 14 ). Labial anterior row formed by five smooth chaetae (a1–a5); posterior row formed by ciliated chaetae with formula M1M2R*EL1L2; chaeta M1 a little shorter than M2; chaeta R half in length of M2, E, L1 and L2 chaetae (marked with *); ventral cephalic groove with 3+3 ciliated chaetae ( Fig. 15 ).

Dorsal macrochaetae formula such as AoA2s A2A4M 2/00/01 *00+3 ( Figs16–17 ). Interocular chaetotaxy with ciliated chaetae s, t, p, and 2–4 scales ( Fig. 18 ). Eyes G and H small and difficult to see on the slides. Th.II–III and abd.I dorsal chaetotaxy as in Figs 19–21 . Abd.II chaetotaxy as in Fig. 22 ; chaetae ml and a2p absent; chaetae mi, a2, lm and ll fan-shaped; chaeta m3 short, ciliated macrochaeta (chaeta marked with * in dorsal macrochetae formula); m5 mesochaeta. Abd.III chaetotaxy as in Fig. 23 ; chaeta d3 absent; chaetae mi, ml, a2, li,lm,ll,a6,im and em fan-shaped, of which a6 and li larger (paddle-like); chaeta am6 strongly ciliated and thicker than other mesochaetae; d2 microchaeta; p6 and pm6 broad ciliated macrochaetae; m7a and p8p thin ciliated macrochaetae; with lateral tuft of ±100 long ciliated filaments ( Fig. 24 ). Abd.IV chaetotaxy as in Fig. 25 ; bothriotrichum T2 without accessory chaeta s; chaetae m, D1, pi and pe fan-shaped, from which m and D1 larger (paddle-like); chaeta a bilobed-fan-shaped ( Fig. 26 ); C1 mesochaeta; macrochaeta B6 with socket of minor diameter than macrochaetae B4 and B5; with seven dorsal long S-chaetae (S-chaetae are smooth, slightly blunt and more translucent under light microscope than normal chaetae, see Zhang & Deharveng 2014); with two lateral pseudopori located external to chaetae r4–r5.

Ventral tube without scales; 7+7 ciliated chaetae on anterior side ( Fig. 27 ); all chaetae on posterior side ciliated; each lateral flap with maximum of 5 ciliated chaetae and 5 smooth chaetae ( Fig. 28 ).

Legs without scales. V shaped trochanteral organ (leg III) with maximum of 14 smooth straight chaetae arranged in triangular shape ( Fig. 29 ). Unguis with well-developed basal pair of teeth at 36% from base of the inner edge, and with two small inner teeth at 71% and 89% from base of inner edge respectively; unguiculus truncate and with apically serrated outer margin; spatulate tibiotarsal tenent hair ( Fig. 30 ). Manubrium without scales on dorsal surface; dentes with small, rounded basal tubercle ( Fig. 31 ); mucronal basal spine with spinelet ( Fig. 32 ); manubrial plate with two pseudopori, 2 inner chaetae, and 2–3 outer chaetae ( Fig. 33 ).

Discussion. The presence of small rounded dental tubercle and spinelet on the basal mucronal spine permit to assign this species to the subgenus Setogaster.

Figures

FIGURE 49. Australian localities of Setogaster species. Red circles— Setogaster sp., blue squares S— Setogaster sp., n— Setogaster nigrofasciatus, p— Setogaster praecisus.

FIGURES 1 – 8. Lepidocyrtus (Setogaster) studied. 1 – 2, L. (Setogaster) nigrofasciatus; 3, L. (Setogaster) praecisus; 4, L. (Setogaster) kuakea; 5, L. (Setogaster) fasciatus; 6, L. (Setogaster) coerulea; 7 – 8, L. (Setogaster) spp.

FIGURES 9 – 15. Lepidocyrtus (Setogaster) nigrofasciatus. 9, ant. I dorsal microchaetae; 10, ant. III dorsal view showing ant. III apical organ; 11, ant. IV apex showing T-chaeta; 12, labrum; 13, outer labial papilla; 14, maxillary palp; 15, labium (left side) and ventral cephalic groove.

FIGURES 16 – 18. Lepidocyrtus (Setogaster) nigrofasciatus. 16, scheme of dorsal macrochaetae (circles), bothriotricha (curved lines), abd. III filaments (straight lines) and pseudopori (#); 17, dorsal head chaetotaxy, circles—ciliated chaetae sockets, small ovals—scale sockets, lines—smooth mesochaetae; 18 a, interocular chaetotaxy (right ocular area), small ovals—scale sockets; 18 b, interocular scale.

FIGURES 19 – 21. Lepidocyrtus (Setogaster) nigrofasciatus. 19, th. II dorsal chaetotaxy (left side), pse—pseudoporus, circles – ciliated chaetae; 20, th. III dorsal chaetotaxy (left side)), pse—pseudoporus; 21, abd. I dorsal chaetotaxy (left side), psepseudoporus.

FIGURES 22 – 24. Lepidocyrtus (Setogaster) nigrofasciatus. 22, abd. II complete chaetotaxy (left side), pse—pseudoporus; 23, abd. III complete chaetotaxy (left side), pse—pseudoporus, chaeta d 2 is a ms chaeta sensu Szeptycki (1972), only one filament of lateral tuft of filaments showed, for the other lateral filaments only the sockets are represented; 24, abd. III lateral tuft of filaments.

FIGURES 25 – 26. Lepidocyrtus (Setogaster) nigrofasciatus. 25 a, abd. IV complete chaetotaxy, broad black circles—broad ciliated macrochaetae, small black circles—thin ciliated macrochaetae, open circles— mesochaetae, triangles—fan-shaped chaetae, S—long S-chaetae, as and ps—short S-chaetae, x—bothriotricha, # — pseudoporus; 25 b, abd. IV chaetae morphology, bcm—blunt broad ciliated macrochaeta, tcm—acuminate thin ciliated macrochaeta, m—mesochaeta; 26, abd. IV bothriotrichal complex.

FIGURES 27 – 33. Lepidocyrtus (Setogaster) nigrofasciatus. 27, ventral tube, anterior side (right side); 28, ventral tube left lateral flap; 29, trochanteral organ; 30, third leg apex with unguis and unguiculus; 32, man –– manubrium, den –– dentes, arrow pointing to dental tubercle; 32, mucro showing basal mucronal spine with spinelet; 33, manubrial plate (left side), filled circles—pseudopori.