Dusmadiores elgonensis sp. nov.

(Figures 1, 4 A–F, 5A–E, 6A–C, 7A–F, 8A–F)

Material examined. Holotype ♂: UGANDA, Manafwa, 1619 m, N 0.8796 E 34.3776, coffee garden, pitfall, 8/ VIII/2014, K. Vanderhaegen (MRAC 244687) . Paratype ♀: UGANDA, Manafwa, 1619 m, N 0.8796 E 34.3776, coffee garden, pitfall, 8/VIII/2014, K. Vanderhaegen (MRAC 244686) . Other material examined: UGANDA, all collected by K. Vanderhaegen in coffee gardens: 10♂ 2♀: Bulambuli, 1640 m, N 1.2928 E 34.3664, pitfall, 20/ VIII/2014 (MRAC 244688) ; 4♂ 1♀: Bulambuli, 1397 m, N 1.2484 E 34.3379, pitfall, 30/VIII/2014 (MRAC 244689); 1♂: Bulambuli, 1996 m, N 1.2845 E 34.3803, litter sieving, 25/VIII/2014 (MRAC 244690); 1♂: Bulambuli, 1905 m, N 1.2888 E 34.3781, litter sieving, 26/VIII/2014 (MRAC 244691); 1♂: Bulambuli, 2129 m, N 1.2804 E 34.3903, pitfall, 25/VIII/2014 (MRAC 244692); 2♂: Bulambuli, 1636 m, N 1.2942 E 34.3699, pitfall, 27/VIII/2014 (MRAC 244693); 3♂ 2♀: Bulambuli, 1658 m, N 1.2936 E 34.3669, pitfall, 27/VIII/2014 (MRAC 244694); 3♂ 2♀: Bulambuli, 1640 m, N 1.2917 E 34.3676, litter sieving, 20/VIII/2014 (MRAC 244695); 1♂: Bulambuli, 1640 m, N 1.2917 E 34.3676, pitfall, 20/VIII/2 0 14 (MRAC 244696); 2♂: Bulambuli, 1580 m, N 1.2574 E 34.3367, pitfall, 28/VIII/2014 (MRAC 244717); 2♂: Bulambuli, 1580 m, N 1.2574 E 34.3367, pitfall, 28/ VIII/2014 (MRAC 244717); 1♂ 2♀: Bulambuli, 1608 m, N 1.2582 E 34.3376, pitfall, 29/VIII/2014 (MRAC 244697); 1♂: Bududa, 1578 m, N 1.0551 E 34.3861, pitfall, 6/VIII/2014 (MRAC 244698); 4♂ 1♀: Bulambuli, 1397 m, N 1.2484 E 34.3379, litter sieving, 30/VIII/2014 (MRAC 244699); 7♂ 1♀: Bulambuli, 1338 m, N 1.2552 E 34.328, pitfall, 29/VIII/2014 (MRAC 244700); 1♂: Bulambuli, 1693 m, N 1.2968 E 34.3746, pitfall, 22/VIII/ 2014 (MRAC 244701); 1♂: Bulambuli, 1616 m, N 1.2962 E 34.3726, litter sieving, 22/VIII/2 0 14 (MRAC 244702); 1♂: Bulambuli, 1781 m, N 1.2981 E 34.3804, litter sieving, 23/VIII/2 0 14 (MRAC 244703); 1♀: Manafwa, 1619 m, N 0.8796 E 34.3776, litter sieving, 8/VIII /2 0 14 (MRAC 244704); 5♂ 1♀: Manafwa, 1619 m, N 0.8796 E 34.3776, pitfall, 8/VIII/2014 (MRAC 244687); 3♂: Manafwa, 1579 m, N 0.8809 E 34.3743, pitfall, 12/ VIII/2014 (MRAC 244706); 1♂: Manafwa, 1501 m, N 0.8978 E 34.3488, pitfall, 15/VIII/2014 (MRAC 244707); 1♀: Manafwa, 1515 m, N 0.9024 E 34.3551, pitfall, 17/VIII/2014 (MRAC 244708); 1♂: Manafwa, 1525 m, N 0.9005 E 34.355, pitfall, 18/VIII/2014 (MRAC 244709); 1♀: Manafwa, 1515 m, N 0.9024 E 34.3551, litter sieving, 17/VIII/2014 (MRAC 244710); 8♂: Manafwa, 1442 m, N 0.8929 E 34.3437, pitfall, 8/VIII/2014 (MRAC 244711); 1♂: Sironko, 1298 m, N 1.1553 E 34.3539, pitfall, 2/IX/2014 (MRAC 244712); 1♂: Sironko, 1297 m, N 1.1545 E 34.3632, pitfall, 3/IX/2014 (MRAC 244713); 4♂: Manafwa, 1530 m, N 0.9024 E 34.3554, pitfall, 16/ VIII/2014 (MRAC 244714); 1♀: Bulambuli, 1616 m, N 1.2962 E 34.3726, pitfall, 22/VIII/2014 (MRAC 244702); 1♀: Sironko, 1297 m, N 1.1545 E 34.3632, litter sieving, 3/IX/2014 (MRAC 244716) .

Etymology. The specific name is an adjective referring to the type locality, Mount Elgon.

Diagnosis. Males of D. elgonensis sp. nov. differ from other species in the genus by the conspicuous retrolateral group of spines on the cymbium just in front of the RTA. Females can be distinguished by the wide epigyne with poorly delimited posterior plate and small atria visible in transparency between the widely separated oval spermathecae. The species is further diagnosed by the femoral organ setae with a combination of grooves and barbs.

Description. Male (Holotype, MRAC 244687). Total length: 1.76. Carapace: length 0.89, width 0.65, height: 0.47. Colour (Figs 4 A –C): Carapace medium brown with darker radiating pattern; region around AME black. Chelicerae, mouthparts and sternum medium brown. Abdomen dorsally dark sepia, sides pale with dark areas around epigastric fold and around spinnerets venter and spinnerets pale cream. Legs uniform pale brown. Carapace: thoracic area granulated as in female (Fig. 7 B).

Eyes: AME large, round, dark; other eyes pale. AME: 0.066; ALE: 0.058; PME: 0.056; PLE: 0.057; AME- AME: 0.032; AME-ALE: 0.015; PME-PME: 0.075; PME-PLE: 0.018.

Clypeus height: 0.18. Sternum length: 0.55, width: 0.52. Abdomen with dorsal scutum (Fig. 4 A). Sperm pore wide (Fig. 8 F). Legs: Femoral organ in shallow alveolus with small openings overhung by three grooved and branched setae on all legs as in female (Figs 7 C–F). Anterior tarsi fusiform (Fig. 4 E).

Leg measurements:

F P T Mt t TOtal I 0.75 0.23 0.65 0.60 0.53 2.76 II 0.62 0.22 0.54 0.55 0.49 2.42 III 0.59 0.19 0.49 0.56 0.49 2.32 IV 0.81 0.22 0.70 0.77 0.61 3.11 Male palp (Figs 5 A –C, 6 A, B, 8C–E): RTA divided, dorsal prong short, with pointed tip, ventral prong longer, narrow, curved outwards, tapered to sharp tip. Cymbium with conspicuous vertically oriented, retrolateral group of spines just in front of RTA; with series of uniseriate modified setae along prolateral margin. Embolus in centre of tegulum, sickle-shaped, roughened with field of tiny grain shapes in median part, distal part twisted, strongly tapered to elongate sharp tip. MA large, with hook shaped extension at base, back-folded flap at distal extremity. Conductor fairly large, broad, transverse across distal part of bulbus, wrapped around embolus.

Female. (Paratype, MRAC 244686). Total length: 2.41. Carapace: length 1.14, width: 0.60, height: 0.55. Colour (Figs 4 D–F): Carapace dark brown with two paler oval areas on either side of fovea. Region around AME black. Chelicerae, mouthparts and sternum medium brown, distal extremity of endites cream. Abdomen dorsally dark sepia, sides and venter as in male. Spinnerets cream. Legs medium brown. Carapace (Figs 7 A, B): with granulations in thoracic area. Eyes: AME: 0.08; ALE: 0.07; PME: 0.06; PLE: 0.06; AME-AME: 0.045; AME- ALE: 0.026; PME-PME: 0.087; PME-PLE: 0.020. Clypeus height: 0.24. Sternum: length: 0.64, width: 0.57. Abdomen without scutum.

Leg measurements:

F P T Mt t TOtal I 0.82 0.28 0.61 0.53 0.53 2.77 II 0.71 0.22 0.52 0.53 0.50 2.48 III 0.68 0.23 0.52 0.54 0.51 2.48 IV 0.86 0.31 0.77 0.88 0.57 3.39 Female palp (Figs 8 A, B): with prolateral row of modified uniseriate setae, chemoreceptors and pectinate claw. Epigyne (Figs 5 D, E, 6C) fairly wide with poorly delimited posterior suboval area; with pair of central atria visible in transparency in front of darker area; spermathecae oval, far apart near posterior margin.

Biology. Out of the 74 surveyed coffee gardens, Dusmadiores elgonensis sp. nov. was present in 24 gardens, spread over 4 districts (Fig. 1). Our knowledge on the phenology of D. elgonensis is limited since sampling was done only in August and September 2014. We did not find a significant direct correlation between the amount of ants collected in the pitfall traps per plot and the abundance of D. elgonensis . However, plots with presence of D. elgonensi s had lower ant abundances (collected by pitfall trapping) than the other plots (70 ± 11 ants versus 111 ± 14 ants, t = 1.8736 P = 0.065). Of the 85 identified D. elgonensis adults, 82% were males and 18% females, juveniles were not identified D. elgonensis seems not too sensitive to disturbance as the soil of half of the plots where it was observed was recently dug and most of the plots were in close vicinity of the farmers’ homesteads. In 90% of the gardens with D. elgonensis, crop residues were left or added as mulch and 60% contained large shade trees (> 30 cm diameter). The 24 coffee gardens out of 74 where D. elgonensis was found were less intensively managed gardens with older coffee shrubs and higher shade levels (74% ± 14% crown closure). These observations suggest that even if D. elgonensis tolerates some disturbance it still prefers less disturbed habitats. The average horizontal distance between the gardens with D. elgonensis and the national park is 3.3 km. The observed altitudes range from 1296 to 2126 m a.s.l..

Distribution. D. elgonensis is known from the mid-altitude slopes on the Uganda side of Mount Elgon (Fig. 1).