Myrmarachne cornuta Badcock 1918
Creators: name: Yamasaki, Takeshi
name: Ahmad, Abdul Hamid
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Salticidae
Myrmarachne
Myrmarachne cornuta

description: Myrmarachne cornuta Badcock, 1918
(Figs 13 A–G, 14A–F)
Myrmarachne cornuta Badcock, 1918: 291, Fig. 5; Edmunds & Prószyński, 2003: 304, Figs 30–39.
Non-type material examined. BORNEO: 1 male, Guramboi, Sabah, 15 III 2008, T. Yamasaki leg.; 1 female, UMS, Sabah, 24 III 2008, T. Yamasaki leg.; 1 male, Kionsum, Inanam, Sabah, 30 III 2008, H. Takizawa leg.; 1 male, Monggis substation, Kinabalu Park, Sabah, 2 X 2009, T. Yamasaki leg.; 1 female, Maliau Basin, Sabah, 9 XI 2011, T. Yamasaki leg.
Diagnosis. Slender and black species with very long pedicel; pedicel longer than ALE–PLE (Figs 13 A, 14A). In males, fang almost straight without tooth-like apophysis. In females, copulatory atria very elongate-oval; spermathecae elongate-oval; anterior part of sclerotised copulatory ducts complexly twisted; median pocket very small, located just in front of epigastric furrow (Figs 14 D–F).
Measurements (male/female). Carapace length 2.25–2.45/2.40, width 1.24–1.40/1.16. Pedicel length 1.15– 1.25/1.05. Abdomen length 3.20–3.25/2.90. Chelicera length 1.90–2.30. Sternum length 1.40–1.48/1.38. Width of eye row I 1.14–1.26/1.14; II 1.04–1.18/1.06; III 1.22–1.32/1.24. ALE–PLE 0.90–0.94/0.92; ALE–PME 0.44/0.46. Eye size: AME 0.39–0.44/0.39, ALE 0.20–0.23/0.20, PME 0.06/0.05, PLE 0.21–0.23/0.23.
Male (Figs 13 A–G). Cephalic part almost flat or weakly convex dorsally. Thoracic part convex dorsally. Chelicera as long as, or slightly shorter than carapace, with seven or eight prolateral and ten or eleven very small retrolateral teeth; two basal prolateral teeth very small. Fang almost straight with curved tip, without tooth-like apophysis. Sternum slender, slightly overlapped by coxae I, II and III. Pedicel much longer than ALE–PLE; second segment longer than first segment. Abdomen very slender and weakly constricted in anterior part, with slender dorsal scutum that is incised on each lateral outline anteriorly.
Palp (Figs 13 E–G). Tegulum oval with strongly c-curved seminal reservoir in anterior part of tegulum. Embolus forming two oval coils; embolus coils occupying more than half of venter of cymbium. RTA strongly curved. Flange of RTA well-developed.
Leg spination. Femur I md 1–2, pd 0–1; patella I rv 1; tibia I pv 4, rv 4; metatarsus I pv 2, rv 2; femur II pd 1; patella II rv 0–1; tibia II pv 1–3, rv 2–3; metatarsus II pv 1–2, rv 2; femur III pd 2–3; femur IV md 1–4, pd 1.
Coloration and pilosity. Carapace dark brown; cephalic part covered with white hairs; white hairs forming lateral marking between cephalic and thoracic parts; thoracic part sparsely covered with long white hairs; white band formed by white hairs running diagonally from above coxa III to summit of thoracic part. Chelicera brown, covered with sparse white hairs dorsally. Maxilla, labium and sternum brown. Coxae I and III cream tinged with black; coxae II and IV cream. Abdomen covered with white hairs; dorsal scutum brown; integument except for scutum pale brown to greyish brown with lateral cream markings; cream markings fringed with white hairs.
Female (Figs 14 A–F). Carapace almost as in males, but thoracic part much higher than that of males. Chelicera with seven prolateral and nine retrolateral teeth. Pedicel and sternum almost as in males. Abdomen very slender without dorsal scutum.
Epigyne (Figs 14 D–F). Copulatory atria containing openings elongate-oval. Spermathecae elongate-oval; anterior part of sclerotised copulatory ducts complexly twisted; sclerotised copulatory ducts thick. Median pocket very small, with two interior small lateral pockets, but not divided in half like M. melanocephala; located just in front of epigastric furrow.
Leg spination. Patella I rv 1; tibia I pv 4, rv 4; metatarsus I pv 2, rv 2; patella II rv 1; tibia II pv 3, rv 3; metatarsus II pv 2, rv 2; femur IV md 1.
Coloration and pilosity. Carapace dark brown; cephalic part covered with white hairs dorsally; lateral marking more distinct than that of males; white band formed by white hairs running diagonally from above coxa III to summit of thoracic part. Chelicera brown. Maxilla, labium and sternum brown. Coxae I, II and IV cream, but coxa I black in some specimens; coxa III tinged with black. Abdomen almost as in males.
Distribution. Malay Peninsula (Badcock 1918; Edmunds & Prószyński 2003), Borneo.
Remarks. Although we did not examine the type material of M. cornuta, our specimens agreed with the original description by Badcock (1918) and redescription by Edmunds & Prószyński (2003).
Myrmarachne cornuta has a very long pedicel. The species is in external appearance similar to M. melanocephala, but they are distinguished from each other by the dentition of the male chelicera and the structure of the epigyne. Especially in females, the copulatory atria are elongate-oval in M. cornuta, but more rounded oval in M. melanocephala.
Biology. The species is arboreal, and often occurs in gardens near forests and forest canopies.
description: Published as part of Yamasaki, Takeshi & Ahmad, Abdul Hamid, 2013, Taxonomic study of the genus Myrmarachne of Borneo (Araneae: Salticidae), pp. 501-556 in Zootaxa 3710 (6) on pages 518-520, DOI: 10.11646/zootaxa.3710.6.1, http://zenodo.org/record/248777