Myrmarachne borneensis Peckham & Peckham, 1907

Yamasaki, Takeshi & Ahmad, Abdul Hamid, 2013, Taxonomic study of the genus Myrmarachne of Borneo (Araneae: Salticidae), Zootaxa 3710 (6), pp. 501-556 : 514-515

Myrmarachne borneensis Peckham & Peckham, 1907

( Figs 10 A–G)

Myrmarachne borneensis Peckham & Peckham, 1907: 604 ; Yamasaki, 2010: 63, Figs 2–7 .

Type material examined. Holotype male (MCZ; Catalog # 20563), Sarawak, BORNEO, G. W. Peckham & E. G. Peckham leg.

Non-type material. BORNEO: 1 juvenile, Danum Valley, Sabah, 16 XII 2006, T. Endo leg.; 1 male, same loc., 18 XII 2006, R. Oie leg.

Diagnosis. Robust species. In males, chelicera relatively short; long spine-like hairs present on tibial flange of palp ( Fig. 10 G).

Measurements (holotype). Carapace length 3.45, width 2.45. Abdomen length 3.45, width 2.00. Chelicera length 1.83. Sternum length 2.00, width 0.83. Width of eye row I 2.07; II 1.92; III 2.50. ALE–PLE 1.73; ALE– PME 0.85. Eye size: AME 0.67, ALE 0.38, PME 0.11, PLE 0.43.

Male ( Figs 10 A–G). Carapace robust; in lateral view posterodorsal corner of cephalic part produced roundly above PLE. Chelicera shorter than carapace, with one apical spur on inner edge of chelicera, and with seven prolateral and 12 small retrolateral teeth. Fang short, like claw, without tooth-like apophysis. Leg I long compared with other legs; femur I basally broad. Abdomen oval, with broad dorsal scutum that is not incised.

Palp ( Figs 10 F–G). Tegulum large oval with strongly curved seminal reservoir in retrolateral part of tegulum. Embolus forming two large oval coils; embolus coils occupying more than half of venter of cymbium. RTA curved with hooked tip. Flange of RTA bearing spine-like hairs on its margin.

Leg spination. Tibia I pv 8, rv 7; metatarsus I pv 2, rv 2; tibia II pv 4, rv 3; metatarsus II pv 2, rv 2.

Coloration and pilosity. Carapace dark brown. Chelicera dark brown with tip lighter. Maxilla, labium and sternum brown. Coxae cream. Abdomen greyish brown with dark brown scutum.

Distribution. Borneo (Peckham & Peckham 1907).

Remarks. The females are unknown. M. borneensis is slightly similar to M. malayana in the external appearance, but M. borneensis is easily distinguished from M. malayana by the spine-like hairs on palpal tibia, the short chelicera and the robust leg I. The strong hairs on palpal tibia are very characteristic and not otherwise known among Southeast Asian Myrmarachne species. However, only M. chickeringi Galiano, 1969 described from Panama has the spine-like hairs on its palpal tibia. The importance of the character in the taxonomy of the genus Myrmarachne is unknown.

Biology. The biology is unknown. Additional specimens were collected in Danum Valley (primary forests) by sweeping.

Figures

FIGURE 10. M. borneensis, male. A, chelicera and carapace, dorsal view; B, abdomen, dorsal view; C, chelicera and carapace, lateral view; D, maxillae, labium, sternum and coxae; E, chelicera and fang, ventral view; F, cymbium, embolus and tegulum; G, palpal tibia, ventral view. (Scales. A – E: 1 mm; F – G: 0.25 mm)

FIGURE 2. M. acromegalis sp. nov., male. A, body, dorsal view; B, chelicera and carapace, lateral view; C, chelicera and fang, ventral view; D, maxillae, labium, sternum and coxae; E, palp, ventral view; F, palp, dorsal view. (Scales. A – D: 1 mm; FIGURES E – F: 0.25 mm)

FIGURE 3. M. acromegalis sp. nov., female. A, body, dorsal view; B, chelicera and carapace, lateral view; C, maxillae, labium, sternum and coxae; D – E, internal structures of epigyne, ventral view; F, internal structure of epigyne, dorsal view. (Scales. A – C: 1 mm; D, F: 0.25 mm; E: 0.10 mm)

FIGURE 4. M. alticephalon sp. nov., male. A, body, dorsal view; B, chelicera and carapace, lateral view; C, chelicera and fang, ventral view; D, maxillae, labium, sternum and coxae; E, palp, ventral view; F, palp, lateral view; G, palp, dorsal view. (Scales. A – D: 1 mm; E – G: 0.25 mm)

FIGURE 5. M. alticephalon sp. nov., female. A, body, dorsal view; B, chelicera and carapace, lateral view; C, maxillae, labium, sternum and coxae; D – E, internal structure of epigyne, ventral view. (Scales. A – C: 1 mm; D: 0.25 mm; E: 0.10 mm)

FIGURE 6. M. assimilis, male. A, chelicera, carapace and pedicel, dorsal view; B, pedicel and abdomen, dorsal view; C, chelicera and carapace, lateral view; D, chelicera and fang, ventral view; E, maxillae, labium, sternum and coxae; F, palp, ventral view; G, palp, lateral view; H, palpal tibia, dorsal view. (Scales. A – E: 1 mm; F – H: 0.25 mm)

FIGURE 7. M. assimilis, female. A, body, dorsal view; B, chelicera and carapace, lateral view; C, maxillae, labium, sternum and coxae; D and F, internal structure of epigyne, ventral view; E, internal structure of epigyne, dorsal view. (Scales. A – C: 1 mm; D – E: 0.25 mm; F: 0.10 mm)