Tropostreptus

Enghoff, Henrik, 2017, A new East African genus of spirostreptid millipedes (Diplopoda, Spirostreptida, Spirostreptidae), with notes on their fungal ectoparasite Rickia gigas, Zootaxa 4273 (4), pp. 501-530 : 507-508

Key to the species of Tropostreptus

The key is valid for adult males only.

1. Metaplica apically with three processes including the long apico-lateral process. Body diameter> 8.5 mm ................ 2

- Metaplica apically with one or two processes including the long apico-lateral process. Body diameter usually <8 mm ...... 3

2. Lateral proplical lobe (lpl) relatively small; antetorsal process (atp) of telopodite curving basad(-laterad) ( Figs 14 , 15 A)................................................................................................... austerus

- Lateral proplical lobe very large; antetorsal process of telopodite curving basad-mesad ( Fig. 15 B)................. severus

3. Apico-lateral process of metaplica strongly reflexed. Body diameter 4.5–6.3 mm ................................... 4

- Apico-lateral process pointing more or less laterad, not reflexed. Body diameter 6.0– 8.8 mm .......................... 5

4. Latero-basad metaplical process blunt; antetorsal process of telopodite long, strongly curved ( Fig. 7 E); body diameter 5.4–6.3 mm ............................................................................................ droides

- Latero-basad metaplical process pointed; antetorsal process of telopodite shorter, weakly curved ( Fig. 7 F; body diameter 4.5– 4.8 mm ......................................................................................... kipunji

5. Birdhead-shaped process of metaplica (bh) very small, not overreaching lateral proplical lobe (lpl) laterally ( Fig. 7 D)................................................................................................ microcephalus

- Birdhead-shaped process longer, overreaching lateral proplical lobe laterally ( Figs 7 A–C, 12)........................ 6.

6. Lateral proplical lobe large; antetorsal process of telopodite very long, strongly curved ( Figs 7 A,B, 12A)......... hamatus

- Lateral proplical lobe) smaller; antetorsal process of telopodite shorter, sigmoid ( Figs 7 C, 12B)............. sigmatospinus

Figures

FIGURE 7. Tropostretus spp., gonopods, anterior view. A: T. hamatus, East Usambara Mts, B: T. hamatus, Udzungwa Mts., left telopodite missing, C: T. sigmatospinus sp. nov., D: T. microcephalus sp. nov., E: T. droides sp. nov., F: T. kipunji sp. nov. Scales 0.5 mm. atp = antetorsal process, bh = birdhead-shaped metaplical process, lpl = apicolateral proplical lobe, map = mesapical metaplical process, mp = metaplica, mpl = mesapical proplical lobe, pp = proplica, px = paracoxite, st = sternum, tlp = telopodite.

FIGURE 14. Tropostreptus austerus, gonopods, anterior view. The birdhead-shaped process of the right gonopod is misshapen; the basad-mesad direction of the antetorsal process is due to drying of the gonopods for scanning electron microscopy. Scale 0.5 mm.

FIGURE 15. Tropostreptus spp., gonopods, left telopodite isolated, anterior view. A: T. austerus, B: T. severus sp. nov., holotype. Scales 1 mm. atp = antetorsal process, bh = birdhead-shaped metaplical process, fl = telepodital flange, lpl = apicolateral proplical lobe, map = mesapical metaplical process, mpl = mesapical proplical lobe. A. Illum photo.