Micropachyiulus corylorum Verhoeff, 1908

Vagalinski, Boyan, Evsyukov, Aleksandr P., Chumachenko, Yuri A. & Zabiyaka, Igor Y., 2023, A review of the genus Micropachyiulus Verhoeff, 1899 and description of the related Armeniopachyiulus gen. nov. (Diplopoda: Julida: Julidae: Pachyiulini), Zootaxa 5239 (2), pp. 221-246 : 225-227

Micropachyiulus corylorum Verhoeff, 1908

Fig. 2

Micropachyiulus corylorum Verhoeff, 1908 (in Verhoeff 1907 (for 1908)): 459–460, figs 21, 22

Hylopachyiulus corylorum: Attems (1926a: 258) ; Attems (1926b: 245); Antić et al. (2018: 227–231 , figs 1–3, 8A, B) Hylopachyiulus likanus Attems, 1926 (in Attems 1926b): 244–245, figs 339–341 (synonymized by Antić et al. 2018)

Hylopachyiulus pygmaeus: Strasser (1966: 44) (synonymization)

Material examined. 1 ♂, 3 ♀♀ ( SMNG), Croatia, Rijeka, Velika Kapela Mts, Delnice, Mrkopalj Valley, W of Sunger, 45.3321°N, 14.8110°E, 780 m a.s.l., Corylus - Acer stand, in litter, 15.X.2010, H. Reip leg.; 1 ♂ ( SMNG), same locality, 45.3324°N, 14.8107°E, 790 m a.s.l., young Picea forest, in litter, same date and collector; 1 ♂, 4 ♀♀, 1 juv. ( IBER), Croatia, Rijeka, Velika Kapela Mts, Lič, Rudine locality, 45.2631°N, 14.7572°E, 750 m a.s.l., open grassy area with small bushes of Juniperus and Corylus , among Corylus litter, sifting, 14.X.2010, H. Reip leg.; 2 ♂♂ ( SMNG), Slovenia, Ilirska Bistrica, Snežnik, Sviščaki mountain area, 45.5677°N, 14.3735°E, 1300 m a.s.l., at the edge of a forested ravine, mostly Fagus , in litter, 11.X.2010, H. Reip leg.

Diagnosis. A species of Micropachyiulus without ommatidia. Very similar to Micropachyiulus ocellatus comb. nov., Micropachyiulus paucioculatus and Micropachyiulus pygmaeus in terms of gonopod conformation, and especially in the shape of the solenomere which ends up with a minute, transversely oriented apical projection.Differs from all these species by the presence of an opisthomeral rod-like process just behind the solenomere. Differs further from M. pygmaeus by a stouter (vs. slender) epiproct bent ventrad (vs. straight) and by the solenomere considerably overreaching tip of mesomeral process, vs. the solenomere being subequal to tip of mesomeral process; from M. paucioculatus by a much shorter solenomere and by the apical outgrowth of the mesomeral process deviating anteriad rather than running parallel to the main axis of the opisthomere; and from M. ocellatus comb. nov. by a much longer epiproct.

Descriptive notes. Legs 1 in males each with a verrucose hump baso-mesally on the distal podomere.

Gonopods ( Fig. 2 ): Promere ( Fig. 2D, P in Fig. 2A ) somewhat higher than opisthomere, relatively elongate, with nearly straight or gently sigmoid mesal margin and an abruptly sigmoid lateral one, the two joining in a nearly right-angled meso-apical corner; mesal (mr) and lateral (lr) ridges short but well-pronounced, distal ridge (dr) long but rather weakly protruding, with just a few minute spines at proximal part; median groove (mg) relatively broad and not too deep. Opisthomere ( Fig. 2B, C, E, F and O in 2A) slender, very gently sigmoid in mesal and lateral views (distally bent slightly anteriad); mesomeral process (m) relatively well-pronounced, lamellar, completely undivided from the opisthomere, except for a small, tapering outgrowth (mp) bent more or less posteriad; posterior lamella (l) moderately pronounced, slightly wrinkled, apically forming a fimbriate margin (fr) protruding behind the solenomere; without setiform filaments on mesal surface; solenomere (s) very slender, rod-like, with a T-shaped tip, i.e. with a small apical projection (sp) set transversely to the main axis of solenomere; an additional rod-like process (r) present just behind the solenomere, being slightly shorter than the latter.

The examined males from Croatia (also taking in consideration the gonopod figures in Antić et al. 2018, based on material from the same country) and Slovenia show some moderate, most likely intraspecific differences: Outgrowth of mesomeral process more gradually bent posteriad and apically smooth in the Croatian specimens, vs. same being abruptly bent posteriad and apically shortly branched in the Slovenian ones; and promere more slender, markedly sigmoid in anterior and posterior views, narrowing all the way to the apex in the Croatian specimens, vs. same being stouter, with mostly straight and parallel side margins in the Slovenian ones.

Distribution ( Fig. 14 , ochre circles). Slovenia: Jesenice (type locality), near Ribnica ( Antić et al. 2018), Snežnik ( Antić et al. 2018, present study); Italy: Friuli –Venezia Giulia: near Ragogna ( Antić et al. 2018); Croatia: Velebit Mtn: Štirovača (type locality of Hylopachyiulus likanus ); other localities in Velebit Mtn ( Antić et al. 2018); Velika Kapela Mts (present study).

Figures

FIGURE 2. Micropachyiulus corylorum Verhoeff, 1908, ♂♂ from Delnice, Croatia (A–C) and Ilirska Bistrica, Slovenia (D–F) (SMNG). A. Left gonopods, lateral view. B. Left opisthomere, lateral view. C. Right opisthomere, mesal, slightly anterior view. D. Right promere, posterior view. E. Left opisthomere, mesal view. F. Distal part of left opisthomere, mesal view. Abbreviations: dr: distal ridge, fr: fringes of posterior lamella, l: posterior lamella, lr: lateral ridge, O: opisthomere, m: mesomeral process, mg: median groove; mp: apical outgrowth of mesomeral process, mr: mesal ridge, P: promere, r: rod-like process, s: solenomere, sp: apical projection of solenomere. Scale bars: 0.1 mm (A), 0.05 mm (B–E), 0.04 mm (F).

FIGURE 14. Distribution of the genera Micropachyiulus Verhoeff, 1899 and Armeniopachyiulus gen. nov.