Holmelgonia Jocqué & Scharff, 2007

Benoît Nzigidahera & Rudy Jocqué, 2014, On the Afrotropical genus Holmelgonia (Araneae, Linyphiidae), with the description of three new species from the Albertine Rift, European Journal of Taxonomy 77, pp. 1-18 : 4-6

Holmelgonia Jocqué & Scharff, 2007

Type species

Elgonella nemoralis Holm, 1962

Diagnosis

The generic definition is wide, as the original diagnosis by Holm (1962) had to be enlarged by Jocqué & Scharff (1986) to accommodate the species from Tanzanian mountain areas. The genus is characterized by the absence of cheliceral stridulating ridges ( Figs 2-3 ); the presence of a double ventral row of setae on the femora; the long tibial spines, two to three times as long as the diameter of the segment; tibia I-IV with 2, 2, 1 and 1 spine, respectively; TMI between 0.32 and 0.7; males lack a cephalic lobe; the palpal tibia dorsally produced into a dorsal process ( Figs 4-5, 7 ).

Key to the species of Holmelgonia (males only)

1. Dorsal tibial apophysis apically without teeth, smoothly rounded and with many long hairs (A) .................................................................................................... H. afromontana sp. nov. (Burundi)

– Dorsal tibial apophysis apically with teeth, sometimes with many hairs....................................2

2. Dorsal tibial apophysis apically with two teeth (C1), each provided with hair (C2) but without teeth or undulation on the margins.............................................................................................3

– Dorsal tibial apophysis with teeth or undulation on the retrolateral margin (B2, dorsal view) or on distal part (B3, retrolateral view), apart from apical teeth (B1, dorsal view)..................7

3. Dorsal tibial apophysis originating at the proximal base of tibia, straight, pointing upward (D1); retrolateral tibial apophysis absent (D2) ........................................................................................... ....................................................... H. brachystegiae (Jocqué, 1981) (Burundi, Malawi, Tanzania)

– Dorsal tibial apophysis obliquely oriented (E1); retrolateral tibial apophysis conical (E2), toothed (F) or rounded at the tip (G)............................................................................................................4

4. Retrolateral tibial apophysis conical (E2) or rounded at the tip (G)...........................................5

– Retrolateral tibial apophysis with teeth (F).....................................................................................6

5. Distal arm of paracymbium with indented posterior process (H); embolus semicircular or sickleshaped (I) ............................................. H. falciformis ( Scharff, 1990) (Uzungwa Mts, Tanzania)

– Distal arm of paracymbium with simple posterior process (J); embolus with sharp bend (K) ... ............................................................ H. annemetteae ( Scharff, 1990) (Uzungwa Mts, Tanzania)

6. Retrolateral tibial apophysis with blackened teeth (F) on the transerverse ridge under the dorsal tibial apophysis ........................... H. annulata ( Jocqué & Scharff, 1986) (Uluguru Mts, Tanzania)

– Retrolateral tibial apophysis with a single tooth on the lateral ridge (L) ................................... .................................................... H. basalis ( Jocqué & Scharff, 1986) (Usambara Mts, Tanzania)

7. Dorsal tibial apophysis with one tooth at the tip (M2); retrolateral tibial apophysis pointed at the tip (M1) ............................................................................ H. disconveniens sp. nov. (Burundi)

– Dorsal tibial apophysis with two teeth at the tip (B1, B2, C1)...................................................8

8. Dorsal tibial apophysis with a row of five teeth on the margin (N) ............................................. ........................................................................................ H. producta (Bosmans, 1988) (Cameroon)

– Dorsal tibial apophysis with undulation on the prolateral margin (B2) or many small teeth near apical part (B3)................................................................................................................................9

9. Dorsal tibial apophysis with undulation on the prolateral margin (B2)....................................10

– Dorsal tibial apophysis with many small teeth on the apical part (B3)....................................12

10. Dorsal tibial apophysis with a large prolateral lobe (O) ................................................................ ..................................................................................... H. holmi (Miller, 1970) (Congo, Cameroon)

– Dorsal tibial apophysis with small prolateral lobes or teeth on the margin (B2)..................11

11. Distal arm of paracymbium rounded at tip (P1), proximal arm broad at base (P2) ...................... ......................................................................................................... H. bosnasutus sp. nov. (Burundi)

– Distal arm of paracymbium hooked at the tip (Q1), proximal arm narrow at base (Q2) .............. ..................................................................................................... H. nemoralis ( Holm,1962) (Kenya)

12. Embolic division ventrally with numerous small teeth (R1); frontal embolar apophysis very long (R2), central embolar apophysis very short (R3) and adjacent to embolus (R4) ............................. ................................................. H. perturbatrix ( Jocqué & Scharff, 1986) (Usambara Mts, Tanzania)

– Embolic division ventrally without teeth; frontal embolar apophysis very long and twisted (S1), central embolar apophysis on lateral side of division (S2) delimiting a concavity provided with numerous small warts (S3) ........... H. projecta ( Jocqué & Scharff, 1986) (Uluguru Mts, Tanzania)

Figures

Figs 2 - 3. Holmelgonia disconveniens sp. nov. (♂, MRAC 227149). 2. SEM micrographs of chelicerae, lateral view, showing absence of stridulating ridges. 3. Detail of previous. Scale bars = 100 μm.

Figs 4 - 10. SEM micrographs. — 4 - 5, 8. Holmelgonia afromontana sp. nov. (♂, MRAC 227153). 4. Palp, retrolateral view. 5. As previous, ventral view. 8. Embolic division, frontal view. — 6, 9. Holmelgonia bosnasutus sp. nov. (♂, MRAC 227145). 6. Palp, retrolateral view. 9. Embolic division, ventral view. — 7, 10. Holmelgonia disconveniens sp. nov. (♂, MRAC 241448). 7. Palp, retrolateral view. 10. Embolic division, frontal view. Scale bars 4 - 7 = 100 μm; 9 - 10 = 50 μm; 8 = 20 μm. E: embolus.