Formosimyrma lanyuensis

The holotype worker was collected in an evergreen forest in Taiwan. This is the only known representative of this montypic genus.

Identification
Terayama (2009) - F. lanyuensis is the only species of the genus Formosimyrma, which is a member of the Solenopsidini tribe in the Subfamily Myrmicinae. Within the genera of tribe Solenopsidini, this ant most closely resembles Mayriella, distributed from Nepal through Southeast Asia into Papua New Guinea and Australia to New Zealand. However, it is distinguished from the latter by the median portion of clypeus with a thin and high longitudinal wall (anterior margin of clypeus armed with a pair of sharp teeth just above the mandibles in Mayriella), 8-segmented antennae (10-segmented in Mayriella), and oval eyes (eyes elongate and lower section narrows into a point in Mayriella).

Distribution based on Regional Taxon Lists
Oriental Region: Taiwan.

Nomenclature

 *  lanyuensis. Formosimyrma lanyuensis Terayama, 2009: 159, figs. 225-229 (w.) TAIWAN.

Worker
Head densely punctate, 1.14 times as long as wide, with slightly concave posterior margin and subparallel sides in full face view. Mandible smooth and triangular, with 7 teeth; apical to basal 2nd teeth acutely triangular, and basal tooth rectangular. Anterior margin of clypeus convex, median portion with a thin longitudinal wall; the wall well produced anteriorlly in full face view. Antenna with 8 segments; scape short, not reaching posterior margin of head, SI = 77; 3rd to 5th segment each wider than long; 6th segment twice as long as length of 5th segment; 7th segment 1.6 times as long as wide; terminal segment 2.5 times as long as wide. Eye oval, 0.05 mm in maximum diameter.

Alitrunk densely punctate, promesonotal dorsum convex, anterior and lateral corners of dorsal disc round, not carinate; propodeal tooth acute, longer than its basal width. Petiole densely punctate, with relatively long peduncle, node with convex dorsal margin and straight anterior and posterior margins; in dorsal view, dorsal disc 0.63 times as long as wide, with convex anterior and posterior margins. Postpetiole densely punctate, higher than long, with convex dorsal margin; in dorsal view, dorsal disc 0.75 times as long as wide.

Gaster smooth and shining, with many sub decumbent hairs.

Measurements (mm). HL 0.63, HW 0.55, SL 0.42, WL 0.70, PL 0.27, PH 0.20, DPW 0.20, PPL 0.15, PPH 0.20, PPW 0.20, TL 2.0.

Color. Head and alitrunk yellowish brown, dorsum of propodeum darker; petiole and postpetiole brown, dorsal surfaces dark brown; gaster brown; antenna and legs yellowish brown.

Type Material
Holotype. Worker, Lanyu is. (Orchid is.), Taidong Pref., 1. x. 1993, M. Terayama leg.

Type depository. NIAES.

Etymology
The specific epithet is based on the name of type locality, Lanyu island.