Pogonosternum laetificum Jeekel, 1982

Decker, Peter, Mesibov, Robert, Voigtländer, Karin & Xylander, Willi E. R., 2017, Revision of the Australian millipede genus Pogonosternum Jeekel, 1965, with descriptions of two new species (Diplopoda, Polydesmida, Paradoxosomatidae), European Journal of Taxonomy 259, pp. 1-34 : 18-21

Pogonosternum laetificum Jeekel, 1982

Figs 6A , 7, 15–17, 26C

Pogonosternum laetificum Jeekel 1982a: 203 , fig. 1

Pogonosternum laetificum – Mesibov 2004: 42 (record). — Nguyen & Sierwald 2013: 1159 (record). — Decker 2016a: 16–25 (record, mention).

Diagnosis

Differs from other Pogonosternum species in having one lighter longitudinal stripe and no median darker stripe; from P. adrianae and P. montanum Decker , sp. nov., primarily by the small femoral process 2 (fp2) and the lateral process (lp) being directed laterally, but also the presence of a rounded subtriangular, not pointed, process on the female leg 2 coxa; male tarsal and tibial brushes present from legpair 1 to 7–12; anterior spiracles obliquely ovoid with anterodorsally extended rim and spiracular filter not or slightly protruding.

Material studied

Holotype

AUSTRALIA: 1 ♂, Victoria, Ferntree Gully National Park , 18 km NNE of Dandenong, station 93, along nature track in temperate rainforest with tree ferns, under logs and litter and in rotting trees, 18 Nov. 1980, leg. C.A.W. Jeekel & A.M. Jeekel-Rijvers ( NBC).

Paratypes

AUSTRALIA: 3 ♀♀, same data as holotype ( NBC).

Other material examined

See Supplement 1 (total: 25 localities, 78 ♂♂, 30 ♀♀, 12 juv.)

Description

MEASUREMENTS. Length ca 1.8–2.4 cm; midbody width ca 1.7–2.1 mm.

COLOURATION. Colour in fresh material ( Figs 15 , 26C ): Margin of lateral edges of collum sometimes slightly lighter. Dorsum with broad median light yellowish brown stripe. On prozonites the trapezoidal paramedian light band slightly broader anteriorly, and on metazonites slightly broader posteriorly, nearly

parallel, broadest at 4/5 of length ( Figs 15D , 26C ). Flanks and area around ozopores slightly lighter ( Fig. 15C ).

STERNITES. No conspicuous sternal cones.

LEGS. Male tarsal and tibial brushes present from legpair 1 to 7, 9 or up to 12 thin out posteriorly, especially on tibia. Female coxa of leg 2 often with rounded process on caudal side directing posterordistad.

GONOPODS. Considerable variability present ( Fig 16 ). Femorite (F) ranging from short and broad, dorsolaterally wider ( Fig. 16 A–D), to long and slender ( Fig. 16 E–H). Prolongation of femorite (prof) long, S-shaped. Femoral process 1 (fp1) laminate, long, subtriangular to lozenge-shaped with pointed tip, projecting distad of lateral process (lp) and reaching solenomere (S). Shape of fp1 ranging from laterally curved and not twisted ( Fig. 16 A–D) to more or less straight and twisted ( Fig. 16 E–H). Femoral process 2 (fp2) small, reduced to a knob or ridge-shaped structure. Lateral process (lp) on lateral side of prof, short, slender, directed distolaterally, not projecting distad of solenomere.

SPIRACLES. Anterior spiracles distinctly obliquely ovoid. Rim raised with anterodorsal side broadly extended, not lobiform and spiracular filter not or slightly protruding. Posterior spiracle ovoid with low rim and spiracular filter not protruding ( Fig. 17 ).

Distribution

Victorian Highlands north and east of Melbourne and northwestern Strzelecki Ranges ( Fig. 7 ).

Remarks

There is no apparent geographical pattern to gonopod variation in P. laetificum (see also Decker 2016a). The distribution of male tarsal and tibial brushes often varies within a population at a single site.

Figures

Fig. 6. A. Pogonosternum laetificum Jeekel, 1982 (NMV K-12203), right vulva, ventral view. B. P. nigrovirgatum (Carl, 1902) (NMV K-13356), right vulva, lateral view. Scale bars: 0.1 mm.

Fig. 15. Pogonosternum laetificum Jeekel, 1982, ♂, from Marysville, Mt Margaret Road (NMV K-12109). A–B. Anterior rings A. Left lateral view. B. Dorsal view. C–D. Rings 10 and 11. C. Left lateral view. D. Dorsal view. E–F. Posterior rings. E. Left lateral view. F. Dorsal view. Scale bars: 1 mm.

Fig. 26. Habitus and live colouration. A. Pogonosternum nigrovirgatum (Carl, 1902), ♂ from Adams Creek Nature Conservation Reserve (SMNG VNR016989). B. P. adrianae Jeeker, 1982, ♂ from Grand Ridge Road (NMV K-13349). C. P. laetificum Jeeker, 1982, ♂ from Toolangi State Forest, Two Hills Road. D. P. jeekeli Decker, sp. nov., ♂ from Warby-Ovens National Park, Taminick Gap Road. E. P. montanum Decker, sp. nov., ♂ (left, NMV K-12183) and ♀ (right, NMV K-13351) from Linden Roth Drive. Scale bars = 5 mm.

Fig. 16. Pogonosternum laetificum Jeekel, 1982, ♂, right gonopod. A–D.ANIC 64-000049 from Cumberland Valley Reserve. E–H. NMV K10249 from Murrindindi River. A, E. Posterior view. B, F. Lateral view. C, G. Anterior view. D, H. Mesal view. Scale bars: 0.5 mm.

Fig. 17. Pogonosternum laetificum Jeekel, 1982, ♂, spiracles, midbody ring, left lateral side (NMV K-9963). Scale bar: 0.1 mm.

Fig. 7. Map of southeastern Australia and Tasmania, showing the known distribution of Pogonosternum spp.: red circles = P. nigrovirgatum (Carl, 1902); green stars = P. laetificum Jeeker, 1982; yellow squares = P. adrianae Jeeker, 1982; blue triangles = P. montanum Decker, sp. nov.; orange diamonds = P. jeekeli Decker, sp. nov. Abbreviation: ACT = Australian Capital Territory.