Dibologonus major, 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.17880988
persistent identifier	https://treatment.plazi.org/id/A5EFEFE2-4170-5912-AB4E-83AA367B3FAB
treatment provided by	ZooKeys by Pensoft
scientific name	Dibologonus major
status	sp. nov.

Treatment

Dibologonus major sp. nov.

Figs 9 B View Figure 9 , 11 View Figure 11 , 16 A View Figure 16

Type material.

Holotype. Male, Baw Baw National Park (Vic), 0.5 km NNE of Mt St Gwinear carpark, site NP 23-18 , -37.8368, 146.3346 ± 25 m, 1270 m, coll. Nicholas Porch, 2023-03 - 15, 2 m 2 litter sample from riparian cool temperate rainforest, NMV K 16008 GoogleMaps . Paratypes. 2 M, details as for holotype, NMV K 16010 GoogleMaps ; 1 M in 95 % EtOH, same details but Mt St Gwinear Road, 1.1 km WNW of junction with Thomson Valley Road, site NP 23-20 , -37.8163, 146.3456 ± 25 m, 1035 m, wet sclerophyll forest, NMV K 16009 GoogleMaps .

Additional material.

None.

Diagnosis.

Much larger than D. minor sp. nov. and D. oedipus sp. nov. Solenomere with apex expanded vs not expanded in D. sladei sp. nov.; the major telopodite division into medial branch and solenomere at ca 1 / 3 telopodite height vs 2 / 3 height in D. minor sp. nov.; solenomere obscuring medial branch vs well-separated from medial branch in D. oedipus sp. nov.

Description.

As for the genus, with the following details. Male colour in alcohol pale yellow, sometimes with fine reddish-brown speckling at collum and paranotal margins. Length ca 13 mm, maximum midbody diameter 1.6 mm. Antenna reaching tergite 3 when manipulated dorsally; relative antennomere lengths 3> (2, 6)> (4, 5); 6 widest. Metatergites with posterior corners projecting a little, more on rings 14–17. Midbody leg ca 1.4 × ring diameter. Brush setae (Fig. 11 A View Figure 11 ) dense, tapering to point curving distally on coxa / trochanter, prefemur, femur, with a few on postfemur, without mid-height notch; sphaerotrichomes (Fig. 11 B View Figure 11 ) on postfemur, tibia and tarsus with flattened globular base and tapering shaft, the shaft declined distally and flattened.

Gonopod telopodites (Figs 9 B View Figure 9 , 11 C View Figure 11 ) straight, almost reaching legpair 4 when retracted, setose posterolaterally to ca 1 / 3 telopodite height. Telopodite divided at ca 1 / 2 height into medial branch and solenomere. Medial branch gradually tapering, divided near base into medial and lateral processes tapering to points, the lateral process a little longer. Solenomere gently curving medially near base, divided at ca 3 / 4 telopodite height into posteromedial and anterolateral processes. Posteromedial process stout, pointed, terminating below other telopodite processes. Anterolateral process subcylindrical, expanding near tip and divided into a stout, pointed, lateral subprocess and a medial subprocess curving medially towards the lateral subprocess tip, and with small subapical tooth curving posterodistally and carrying the termination of the prostatic groove.

Name.

Adjective; Latin major , “ greater ”. This is the larger of the two species of Dibologonus gen. nov. co-occurring near Mt Baw Baw.

Distribution.

Collected at two sites ca 2.5 km apart near Mt St Gwinear (Fig. 16 A View Figure 16 ), in wet sclerophyll forest at 1035 m and cool temperate rainforest at 1270 m. Co-occurs with D. minor sp. nov.

Remarks.

No females of this species have yet been recognised, and none of the four males examined have modified legs as seen in D. oedipus sp. nov.