Machilontus (Protumidolontus), 2012

Song, Zhi-Shun, Mendes, Luis F. & Huang, Fu-Sheng, 2012, A Review Of Microcoryphia Fauna From Vietnam, With New Subgenus, New Species Of Machilontus Silvestri (Machiloidea: Meinertellidae), And New Data For Sexual Dimorphism In The Order, Raffles Bulletin of Zoology 60 (2), pp. 313-327 : 320

Machilontus (Protumidolontus) , new subgenus

Type species. — Machilontus (Protumidolontus) lii , new species

Diagnosis. — Compound eyes large, distinctly convex, and wider than its length. Lateral ocelli sole-shaped, sublateral to eyes. Frons sexually dimorphic, strongly produced in a large robust process between lateral ocelli in males and slightly protruded in females. Antennae sexually dimorphic, scapus with two bumps providing with dense long dark setae in males, but bump and long dark setae absent in females. Maxillary palps with article III distinctly elongate, nearly 2.5 times in males and 1.7 times in females longer than article II. Labial palps with article II distinctly elongate, with a conspicuous process on apex (process larger and longer in males than in females). Hind coxae with coxal stylet. Tarsi with two articles. Coxites I–VII each with a pair of eversible vesicles and coxites II–IX with stylets. Penis relatively big, nearly as long as half of coxites IX. Ovipositor tertiary type.

Etymology. — The new subgenus name is from the Latin “ Protumidus ”, which means the prominent frons in males. The termination “lontus” is after the suffix of Machilontus Silvestri, 1912 . The gender is masculine.

Remarks. — The new subgenus can be distinguished from other Machilontus subgenera by the much longer article III of maxillary palps; the much longer article II of labial palps with a distinct process on apex; and several particular sexual dimorphism of non-genital portions (e.g., frons strongly produced in a large process between lateral ocelli, antennal scapus with two bumps providing with long dark setae and special chaetotaxy on frons, scapus and maxillary palps in males). In comparison to M. (s. str.) and M. (Megalopsobius), these distinct characters seem to be autapomorphic within Machilontus , but they can not be considered significant enough to establish different taxa beyond the subgeneric level.

A similar case also occurs in the family Machilidae . Corethromachilis gibba Carpenter, 1916 from Seychelles was considered later by Paclt (1969) as the type species of his genus Dromadimachilis because of the frons protruding in a conspicuous process and the hump-shaped metanotum. Sturm (2001) reevaluated the characters and recognised Dromadimachilis as a subgenus of Corethromachilis . Graphitarsus (Hybographitarsus) riedeli Sturm, 2001 from Halmahera in Indonesia is a similar case as well.