Myrmarachne melanocephala MacLeay, 1839

Yamasaki, Takeshi & Edwards, G. B., 2013, The genus Myrmarachne (Araneae, Salticidae) in Flores, Indonesia, ZooKeys 299, pp. 1-20 : 12-15

Myrmarachne melanocephala MacLeay, 1839 Figs 46-58

Myrmarachne melanocephala MacLeay, 1839: 11, pl. 1, fig. 4; Galiano 1969: 146; Edwards and Benjamin 2009: 5, figs. 1 A–H, 2 A–D, 3 A–D, 4 A–E, 5 A–D.

Mymecia melanocephala Walckenaer, 1841: 462.

Salticus contractus Karsch, 1880: 396.

Salticus providens Peckham & Peckham, 1892: 34.

Myrmarachne providens : Simon 1901: 500.

Myrmarachne ramosa Badcock, 1918: 303, fig. 8; Edmunds and Prószyński 2003: 301, figs. 8-21.

Myrmarachne albicrurata Badcock, 1918: 306, fig. 9a.

Myrmarachne lateralis Badcock, 1918: 310, figs. 9 b–c.

Non-type material examined.

1 male and 2 females. Mego [= 8°40'S, 122°2'E], Sikka, Flores, East Nusa Tenggara Prov., INDONESIA, 16.X.2012, T. Yamasaki leg.

Diagnosis.

Slender, light to dark brown species with relatively long pedicel. Males distinguished from other species by pedicel, which is as long as ALE–PLE (Fig. 46); further distinguished from species having long pedicel such as Myrmarachne assimilis Banks, 1930 (cf. figs 7, 13 in Banks 1930), Myrmarachne cornuta Badcock, 1918 (cf. figs 30-35 in Edmunds and Prószyński 2003) and Myrmarachne plataleoides (O. Pickard-Cambridge, 1869) (cf. figs 1-7 in Edmunds and Prószyński 2003) by shape and dentition of chelicera (Fig. 49). Females distinguished from others species by long pedicel as in males (Fig. 54); further distinguished from species having long pedicel such as Myrmarachne assimilis , Myrmarachne cornuta , Myrmarachne glavisi Prószyński & Deeleman-Reinhold, 2010 and Myrmarachne plataleoides by markings on abdomen (Fig. 54) and structure of epigyne (Figs 57-58).

Measurements (male/female).

Carapace length 2.13/2.18-2.37, width 1.15/1.10-1.18. Chelicera length 1.22. ALE–PLE 0.82/0.77-0.83; ALE–PME 0.40/0.36-0.38. Width of eye row I 1.03/1.03-1.12; II 0.97/1.00-1.08; III 1.13/1.15-1.20. Eye size: AME 0.33/0.33-0.35; ALE 0.18/0.16-0.17; PME 0.06/0.05; PLE 0.19/0.19.

Male (Figs 46-53). Cephalic part almost flat dorsally, higher than thoracic part; thoracic part swollen dorsally; strongly incised laterally between cephalic and thoracic part (Figs 46-47). Chelicera shorter than carapace, bearing eleven prolateral and seven retrolateral teeth on its venter; fang weakly sinuous, without distinct tooth-like apophysis (Figs 49-50). Pedicel relatively long (0.50 mm). Abdomen elongate-oval; two dorsal scuta strongly incised laterally between them (Figs 46-47).

With palp in dorsal and ventral views, cymbium oval, without distinct spines on its apex (Fig. 51). Tegulum round, with C-shaped ejaculatory duct in its distal retrolateral part (Fig. 51). Embolus forming two round coils; ventral coil much narrower than basal coil, and basal coil slightly narrower than venter of cymbium (Fig. 51). RTA strongly curved and tip spiraled, with well-developed flange (Figs 52-53).

Number of spines on legs. Femur I pd 1, rd 0; tibia I pv 4, rv 4; metatarsus I pv 2, rv 2; tibia II pv 0, rv 2; metatarsus II pv 2, rv 2.

Coloration in alcohol and pilosity. Cephalic part dark brown, covered with white setae; thoracic part light brown, sparsely covered with white setae; lateral surface above coxa II densely fringed with white setae (Figs 46-47). Chelicera dark brown. Endite and labium brownish orange, tinged with black, especially labium (Fig. 48). Sternum brownish orange (Fig. 48). Coxae and trochanters I, II and IV white, IV with lateral black stripes; coxa and trochanter III black except venter of trochanter light brown (Fig. 48). Abdomen covered with fine setae; anterior dorsal scutum grayish pale brown, and posterior dorsal scutum black; white transeverse band between scuta running diagonally from lateral to ventral area (Figs 46-47).

Female (Figs 54-58). Carapace strongly incised laterally behind PLE; cephalic part almost flat dorsally, slightly higher than thoracic part; thoracic part swollen dorsally (Figs 54-55). Chelicera bearing five prolateral and six retrolateral teeth on its venter. Pedicel relatively long (0. 58-0.83 mm). Abdomen elongate-oval, dorsal scuta inconspicuous (Figs 54-55).

Epigyne (Figs 57-58). Copulatory atria laterally-oriented oval. Lateral pockets present in front of epigastric furrow, rather widely separated. Sclerotized copulatory ducts from "figure 8" adjacent to ovoid spermathecae, then extending between atria to approximate vicinity of widely separated lateral pockets.

Number of spines on legs. Tibia I pv 4, rv 4-5; metatarsus I pv 2, rv 2; tibia II pv 1-3, rv 2-3; metatarsus II pv 2, pv 2.

Coloration in alcohol and pilosity. Cephalic part black, covered with sparse white setae dorsally; thoracic part light to dark brown, sparsely covered with white setae; lateral surface of carapace above coxa II white, densely fringed with white setae (Figs 54-55). Chelicera light brown. Endite, labium and sternum brownish orange, weakly tinged with black laterally (Fig. 56). Coxae and trochanters similar to those of males, except venter of coxa III also light brown (Fig. 56). Abdomen covered with white and fine setae (Figs 54-55).

Remarks.

Myrmarachne melanocephala are very similar to Myrmarachne glavisi , a long-pedicled species, in males (cf. figs 117, 119-120 in Prószyński and Deeleman-Reinhold 2010). However, the females of Myrmarachne melanocephala are distinguishable from the females of Myrmarachne glavisi by the structure of the epigyne (cf. figs 125-126 in Prószyński and Deeleman-Reinhold 2010). We here consider Myrmarachne melanocephala different from Myrmarachne glavisi . However, the taxonomic status of Myrmarachne glavisi should be reviewed by a detailed comparison between the type materials of Myrmarachne glavisi and Myrmarachne melanocephala in the future.

The male specimen examined in the present study has relatively short chelicera compared with specimens from other areas. The male chelicera varies in the length depending on the body size within a species. The female specimens examined here agree with the description of Myrmarachne melanocephala and specimens from other areas, in particular the gray abdomen with transverse median black band is typical of populations throughout Southeast Asia, but lighter in color than the mostly black topotypical specimens from India. This seems to be only regional color variation.

Biology.

The specimens were collected from plantation areas.

Distribution.

Widely distributed in South and Southeast Asia.