Myrmarachne MacLeay, 1839

Benjamin, Suresh P., 2015, Model mimics: antlike jumping spiders of the genus Myrmarachne from Sri Lanka, Journal of Natural History 49 (43), pp. 2609-2666 : 2611-2613

Key to the Sri Lankan species of Myrmarachne

1. Tegulum of the male palp cylindrical, embolus is positioned on distal end of the tegulum, spermatheca kidney-shaped, connected by a CD to CO. Proximal half of chelicerae constricted. Generally not found in primary forest ( Figures 30A–D , 31A , 35B , 36C , 37B, D ) .................................................................... 2

– Tegulum spherical or disk-shaped, embolus is positioned on outer edges of the tegulum, spermatheca elongated tubes or oval. Generally found in primary forest ( Figures 3A, F , 4B , 22A ) ...................................................................... 3

2(1). Spiders brown in colour, large (7.2–30.0), Figure 29A, B ........ M. plataleoides

– Spiders black in colour, much smaller (6.4–3.6), Figure 33A–D ........ M. spissa

3(1). Spermatheca oval, connected by a CD to CO ................................................ 4

– Spermatheca an elongated tube, no clear distinction of CD ........................... 5

4(3). Adult spiders brownish with thoracic part black .................. M. melanocephala

– Adult spiders black with thoracic part red/brown ( Figures 23A–E , 24A–D ) ............................................................................................................. M. prava

5(3). Opisthosoma cylindrical, as much as 3× longer than wide, no constriction ( Figures 5A–C , 8G, H , 9A–D ) ....................................................................... 6

– Opisthosoma oval or round, less than 2× longer than wide, constriction present in the centre of the anterior half of opisthosoma ........................................... 7

6(5). Adult spiders brownish with conspicuous white bands on prosoma and chelicerae ( Figures 5A–C , 8G, H ) ..................................... M. dishani sp. n.

– Adult spiders dark brown with no white bands on prosoma or chelicerae ( Figure 9A–D ) .............................................................................. M. imbellis

7(5). male palp longitudinally oval, embolus is positioned away from the borders of the tegulum ( Figure 3A, F ) .................................................................... 8

– Male palp circular, disk-shaped, embolus is positioned on the borders of the tegulum, small spiders ( Figures 7B , 22A ) ................................................... 9

8(7). Chelicerae with parallel lateral sides, distal half slightly wider than the proximal half, RTA hook-shaped with a constriction at the base ( Figures 2A, B , 3B , 4D, E ) ...................................................................................... M. bicurvata

– Distal half of the chelicerae wider than the proximal half, The inner and outer sides of the proximal half are parallel, whereas the distal half has convex outer sides and parallel inner sides, RTA of the male palp is broad based and tapered to a point in one corner ( Figures 2E, F , 3E, F ) ............. M. ramunni

9(7). Chelicerae fangs with a bulbous base, thickest at the centre ( Figure 38A, B ) ................................................................................................... M. aff. tristis

– Chelicerae without a bulbous base, if base constricted, the entire proximal half is constricted ...................................................................................... 10

10(9). Chelicerae outer sides more or less parallel, dorsum curved, body covered with fine white hairs ( Figures 14A–G , 15A, B ) ........ M. paludosa comb. nov.

– Entire proximal or distal half of chelicerae constricted or dorsal surface flat ( Figure 21A, B ) ......................................................................................... 11

11(10). Proximal half of chelicerae constricted, distal half laterally rounded, dorsal and ventral surfaces well rounded forming a bulb ( Figure 21A, B ) ............... .................................................................................. M. morningside sp. nov.

– Chelicerae proximal half not constricted, dorsal surface flat ( Figure 1A, B ). .................................................................................... M. aurantiaca sp. nov.

Taxonomy

Family Salticidae

Genus Myrmarachne MacLeay, 1839

Panachraesta Simon, 1900: 405 . Type species by original designation P. paludosa Simon, 1900: 405 , examined. New synonymy.

Remarks

The type species of Myrmarachne , M. melanocephala was redescribed and a neotype designated by Edwards and Benjamin (2009). The type species of Panachraesta is here considered a typical member of the genus Myrmarachne ; see redescription of the species below. Diagnosis and description for the genus is provided by Wanless (1978),

Edwards and Benjamin (2009), Prószyński and Deeleman-Reinchold (2010) and Yamasaki and Ahmad (2013).

Figures

Figure 1. Myrmarachne aurantiaca sp. nov., male holotype from Ethagala range (MHNG). (A,B) male dorsal view; (C,D) male palp (C, ventral D, retrolateral). Scale bars = 0.2 mm.

Figure 2. (A–D) Myrmarachne bicurvata. (A,B) male from Lahugala; (C,D) holotype, Sri Lanka, OUMNH. (E,F) Myrmarachne ramunni from Inginiyagala. (A,C,F) dorsal view; (B,D,E) retrolateral view.

Figure 3. (A–D) Myrmarachne bicurvata. (A,B) male from Lahugala; (C,D) holotype, Sri Lanka (OUMNH); (E,F) Myrmarachne ramunni from Inginiyagala; (A,C,F) ventral view; (B,D,E) retrolateral view. Scale bars = 0.2 mm.

Figure 4. Scanning electron micrographs of Myrmarachne bicurvata (USNM). (A–F) right male palp. (A) prolateral view; (B,F) ventral view; (C,D,E) retrolateral view. Scale bars = 10 µm (D,E) 20 µm (A,C) 30 µm (F) 40 µm (B).

Figure 5. Myrmarachne dishani sp. nov. (A–C) male in life from Morningside, Sri Lanka (MHNG).

Figure 7. Scanning electron micrographs of Myrmarachne dishani sp. nov. (USNM). (A–F) male palp. (A,F) prolateral view; (B) ventral view; (C–E) retrolateral view. Scale bars = 10 µm (D); 20 µm (E,F); 100 µm (A,B,C).

Figure 8. Photographs of Myrmarachne imbellis (A–F) and M. dishani sp. nov. (G,H). (A,B) male syntype (MVZ–21602); (C,D) male from Kandaela (USNM); (E,F) female from Pidurutalagala (MZT). (G,H) male from Kanneliya (USNM). (A,C,E,G) dorsal view; (B,D, F,H) lateral view.

Figure 9. Myrmarachne imbellis, male in life from Horton Plains, Sri Lanka (MHNG).

Figure 14. Myrmarachne paludosa (Simon, 1900) comb. nov. In life. (A,D,E) male; (B,C,F,G) female.

Figure 15. Myrmarachne paludosa (Simon, 1900) comb. nov. (A,B) male from Kandy. (C,D) (E–G) female from Kitulgala. (H) female from Corbetts Gap. (A,C) dorsal view; (B,D) lateral view; (E,H) epigynum, ventral view; (F) vulva, dorsal view; (G) vulva, ventral view. Scale bars = 0.1 mm (F,G); 0.2 mm (E,H).

Figure 21. Myrmarachne morningside sp. nov. (A–D) male holotype. (A) dorsal view; (B) lateral view; (C) male palp, ventral view; (D) male palp, retrolateral view. Scale bars = 0.1 mm.

Figure 22. Myrmarachne morningside sp. nov. (A–D) male palp. (A) ventral view; (B–D) retrolateral view. Scale bars = 10 µm (D); 100 µm (A,B,C).

Figure 23. Myrmarachne prava in life. (A–D) male from Nikaravatiya; (E) juvenile.

Figure 24. Myrmarachne prava in life. (A–D) female from Nikaravatiya.

Figure 29. Myrmarachne plataleoides in life. (A,C) male; (B,D) female.

Figure 30. Myrmarachne plataleoides. (A,B) male palp. (A) ventral view; (B) retrolateral view; (C) vulva, ventral view; (D) vulva, dorsal view. Scale bars = 0.1 mm (C,D); 0.2 mm (A,B).

Figure 31. Scanning electron micrographs of Myrmarachne plataleoides. (A–E) male palp. (A,E) ventral view; (B–D) retrolateral view. Scale bars = 20 µm (B); 25 µm (C,E); 30 µm (A,D).

Figure 33. Myrmarachne spissa, male in life.

Figure 35. Myrmarachne spissa. (A–F) male palp. (A,B) male from Bellanwila-Attidiya; (C,D) male from Angunakolaplesse; (E,F) syntype, right palp (MVZ 23159). (A,C,E) retrolateral view; (B,D,F) ventral view. Scale bars = 0.2 mm.

Figure 36. Myrmarachne spissa. (A–C) female from Bellanwila-Attidiya. (A) epigynum, ventral view; (B) vulva, dorsal view; (C) vulva, ventral view. Scale bars = 0.1 mm.

Figure 37. Scanning electron micrographs of Myrmarachne spissa from Padaviya. (A–F) right male palp. (A) prolateral view; (B,D–F) ventral view; (C) retrolateral view. Scale bars = 10 µm (F); 20 µm (A–E).

Figure 38. Myrmarachne aff. tristis (Simon, 1882). (A,B) Photographs of male from Kimbissa; (C,D) left male palp. (A) dorsal view; (B) lateral view; (C) ventral view; (D) retrolateral view. Scale bars = 0.2 mm.