Dibologonus minor, Mesibov, 2025

Mesibov, Robert, 2025, Dalodesmid millipedes from alpine and subalpine habitats in New South Wales and Victoria, Australia (Diplopoda, Polydesmida, Dalodesmidae), ZooKeys 1262, pp. 303-333 : 303-333

publication ID	https://doi.org/10.3897/zookeys.1262.176273
publication LSID	lsid:zoobank.org:pub:FCCCF129-31BF-4258-BF12-1D1887B901AA
DOI	https://doi.org/10.5281/zenodo.17880990
persistent identifier	https://treatment.plazi.org/id/649CFDA3-0B94-5C30-9ABC-BE4BC1192382
treatment provided by	ZooKeys by Pensoft
scientific name	Dibologonus minor
status	sp. nov.

Treatment

Dibologonus minor sp. nov.

Figs 9 C View Figure 9 , 12 View Figure 12 , 16 A View Figure 16

Type material.

Holotype. Male in 95 % EtOH, Mt Baw Baw, 0.43 km S by W of Mt Baw Baw summit, site HS 20-C-L 3 , -37.8433, 146.2748 ± 25 m, 1410–1430 m, 2024-02 - 13, coll. Nicholas Porch and Daniel Kurek, 1 m 2 litter sample from closed shrubby subalpine woodland, NMV K 16012 GoogleMaps . Paratypes. 1 M, 2 F, Baw Baw Tourist Road, 0.79 km WNW of Baw Baw Alpine Resort entrance, site NP 23-11 , -37.8475, 146.2324 ± 25 m, 760 m, 2023-03 - 05, coll. Nicholas Porch, 2 m 2 litter sample from snow gum woodland, NMV K 16505 GoogleMaps ; 2 M, same details but Baw Baw Alpine Reserve, near NE middle of carpark 3, site NP 23-05 , -37.8382, 146.2611 ± 25 m, 1460 m, NMV K 16503 GoogleMaps ; 1 F, same details but Baw Baw Alpine Reserve, 40 m N of Saxons Picnic Area, site NP 23-08 , -37.8354, 146.2589 ± 25 m, 1435 m, NMV K 16011 GoogleMaps ; 1 M, 2 F, same details but Baw Baw Alpine Reserve, 0.1 km NE by E of Saxons Picnic Area, site NP 23-10 , -37.8352, 146.2599 ± 25 m, 1430 m, NMV K 16504 GoogleMaps ; 1 M, same details but Baw Baw National Park, 0.5 km NNE of Mt St Gwinear carpark, site NP 23-18 , -37.8368, 146.3346 ± 25 m, 1270 m, 2023-03 - 15, NMV K 16013 GoogleMaps ; 2 M, same details but Mt Baw Baw Alpine Reserve, 0.35 km W of Mt Baw Baw summit, site HS 27-O-L 3 , -37.8371, 146.2734 ± 25 m, 1560 m, coll. Nicholas Porch and Aidan Fitt, grassy / shrubby snow gum woodland, NMV K 16014 GoogleMaps .

Additional material.

None.

Diagnosis.

Much smaller than D. sladei sp. nov. and D. major sp. nov. Distinguished from the other three species of Dibologonus gen. nov. in having the major division into medial branch and solenomere at ca 2 / 3 telopodite height vs 1 / 3 height.

Description.

As for the genus, with the following details. Colour in alcohol pale yellow, sometimes with fine reddish-brown speckling at collum and paranotal margins. Adult male / female approximate measurements: length 8 / 9 mm, maximum midbody diameter 0.8 / 0.9.

Male with antenna almost reaching tergite 3 when manipulated dorsally; relative antennomere lengths 6> 3> 2> (4, 5); 6 widest. Metatergites slightly wider posteriorly, midbody metatergite width ca 1.2 × prozonite width. Midbody leg ca 1.4 × ring diameter. Brush setae tapering to point curving a little proximally, with mid-height notch as in D. sladei sp. nov. on coxa / trochanter, prefemur, femur; sphaerotrichomes (Fig. 12 C View Figure 12 ) on postfemur, tibia and tarsus with very small globular base and pointed shaft, the tip not curving.

Gonopod telopodites (Figs 9 C View Figure 9 , 12 A, B View Figure 12 ) straight, almost reaching legpair 5 when retracted, sparsely setose posterolaterally to ca 1 / 2 telopodite height. Telopodite divided at ca 2 / 3 telopodite height into medial branch and solenomere. Medial branch divided near base into medial and lateral processes, the medial process shorter and further divided into parallel, bluntly pointed subprocesses; medial branch hidden in posterior view by solenomere. Solenomere divided at ca 3 / 4 telopodite height into anterolateral process and posteromedial process, with small rounded tooth on posterior telopodite surface near division. Anterolateral process flattened, curving slightly medially near tip, the apex with a cluster of four or five small teeth. Posteromedial process with small, horn-like, posterior subprocess curving laterally, the prostatic groove terminating at tip; posteromedial process then extending distally as flattened subprocess, becoming cylindrical and curving posterolaterally, with minute teeth on margins and at apex, and with small, basally directed tooth above horn-like subprocess.

Female a little larger than male, epigynum subrectangular; cyphopods not examined.

Name.

Adjective; Latin minor , “ less ”. This is the smaller of the two species of Dibologonus gen. nov. co-occurring near Mt Baw Baw.

Distribution.

Collected over a ca 9 km linear range near Mt Baw Baw (Fig. 16 A View Figure 16 ), in subalpine woodland and riparian rainforest from 760 to 1560 m. Co-occurs with D. major sp. nov.

Remarks.

None of the males examined have modified legs as seen in D. oedipus sp. nov.