Stenaphorura lubbocki Bagnall, 1935

Rusek, Josef, 2010, The enigma of the genus Stenaphorura Absolon, 1900 (Collembola, Tullbergiinae), Zootaxa 2338, pp. 43-53 : 49-52

Stenaphorura lubbocki Bagnall, 1935

Figs 11–18

Material. Lectotype, first label: type, Dames Dyke, EYks, n/s viii.34 R.S. Bagnall Coll. Brit. Mus. 1959–591, second label: Stenaphorura quadrispina Börner Det. J.T.Salmon Oct. 1960 .

This specimen was designated as a lectotype, as recommended by P. N. Lawrence in a letter to me of 11th October, 1976: ”Although the slide (of lubbocki ) is marked “ TYPE ”, it is evident, from the original description, that it is one of two syntypes.”

Redescription. Body elongated ( Figs 11, 12 ), 1330 μm long and 280 μm wide, white. Granulation of integument unequally large, coarse, with areas of very large secondary granules, especially on head and last abdominal tergite (3 μm in diameter) ( Figs 17, 18 ). Secondary granules on nota and abdominal tergites 1.5–2 μm in diameter.

Macrosetae well differentiated from the microsetae (Figs 11,12). Chaetotaxy of dorsal side of body as in following formula:

1) m2, m4 and m5 present, 2) p2 missing, 3) p2 present, 4) m2 and m4 present, 5) p2 missing, 6) m2, m3 and m4 present, 7) a1 missing (transferred into m-row as m1 chaeta), 8) m1, m2 and m4 present, 9) p2, p3, p5 and one unpaired p x present, 10) only m4 present.

Lengths of some setae: metanotum—a1 12 μm, m2 38 μm, m4 50 μm, p3 15 μm, p5 26 μm, s’ 3 μm; abdominal tergite IV––a2 17 μm, m1 15 μm, m2 60 μm, m4 60 μm, p x 11 μm, p2 13 μm; abdominal tergite V––a1 16 μm, a2 71 μm, m4 80 p2 23 μm, p3 16 μm, p5 16 μm.

Pseudocelli of oval shape 6–8 x 9 μm in size, with crescent, narrow opening, the lid with fine primary granulation and three, sometimes indistinct rips ( Fig. 15 ). Number and arrangement of pseudocelli: 11/111/ 11111 ( Figs 11 , 2 ).

Antennae (135 μm) shorter than head (270 μm). Lengths of antennal segments I: II: III: IV as 30: 30: 35: 40 μm. On antennal segment IV ( Fig. 13 ) five thickened sensilla a–e and two short, thin sensory rods (microsensillum and subapical organite) in indistinct pits. Sensillum d does not reach insertion of sensillum a, and sensillum e reach clearly insertion of sensillum c. Apical vesicle small, globular with a shallow depression on top ( Figs 13, 14 ). Antennal organ III with two small, thin sensory rods concealed behind integument folds, and three thick sensory clubs. Integumantal fold subdivided into three papillae ( Fig. 13 ), not covering sensory clubs. One thick and bent sensory club present on ventral side of antennal segment III ( Figs 13, 14 ).

Postantennal organ ( Fig. 17 ) 40 μm long, 6.3 times longer than frontal pseudocellus, in shallow depression with 75 simple, slim and narrow vesicles lying in two parallel rows.

Legs without clavate tibiotarsal hairs. Claw without teeth, 30 μm long, empodial appendage small, 3 μm long. Each segment of all pairs of legs with areas or rings of coarse granulation on smooth integument.

Setae p2, p3 and p5 on abdominal tergite V as sensilla, slim, not as thickened as in Mesaphorura spp. Abdominal tergite VI with two pairs of anal spines on distinct papillae ( Fig. 18 ), without crescent ridges in front and without wart-like tubercles. Anal spines 30 μm (anterior ones) and 48 μm (posterior pair) long. Dorsal transversal row between both pairs of anal spines with three mesochaetae.

Ventral tube with 6+6 setae (including the basal ones). No trace of furca. Only one female examined: genital plate with 2 microchaetae on frontal lid.

Affinity. Stenaphorura lubbocki is related to S. japygiformis . The differences between them are given in the Discussion of S. japygiformis .

Figures

FIGURES 11 – 12. Stenaphorura. lubbocki Bagnall, 1935: 11, dorsal chaetotaxy of head, pro-, meso- and metanotum; 12, dorsal and lateral chaetotaxy of abdominal segments I – VI. Scale bar: 100 μm for 11, 12.

FIGURES 13 – 18. Stenaphorura. lubbocki Bagnall, 1935. 13, dorsal chaetotaxy of antennal segments III and IV; 14, ventral chaetotaxy of antennal segments III and IV; 15, pseudocellus from abdominal tergite V; 16, lateral sensillum s and sensory rod s’ on metanotum; 17, anterior pseudocellus, postantennal organ and surrounding granulation and chaetotaxy; 18, dorsal and lateral chaetotaxy and part of granulation on abdominal segments V – VI. Scale bar: 40 μm for 18; 30 μm for 13, 14; 20 μm for 15, 16; 10 μm for 17.

FIGURES 1 – 2. Stenaphorura japygiformis Absolon, 1900: 1, dorsal chaetotaxy of head and nota; 2, dorsal and lateral chaetotaxy of abdominal segments I – VI. Scale bar: 100 μm for 1, 2.