Metioche Stål, 1877

Tan, Ming Kai, Baroga-Barbecho, Jessica B. & Yap, Sheryl A., 2019, Taxonomic notes on Trigonidium and related groups with one new species from the Philippines (Orthoptera: Trigonidiidae; Trigonidiinae), Zootaxa 4564 (2), pp. 573-587 : 575

Metioche Stål, 1877

Trigonidium (Metioche) : Stål, 1877: 48; Gorochov, 1987: 10; Otte, 1994: 46; Sugimoto, 2001: 81 –87.

Metioche: Kirby, 1906: 78 ; Chopard, 1951: 467; Chopard, 1968: 331; Chopard, 1969: 295; Yin & Liu, 1995: 185; Storozhenko & Paik, 2007: 111; Kim, 2013: 75.

Trigonidium: Ichikawa, 2001: 45 –58

The literature treated Metioche vastly different, either as a distinct genus or a subgenus of Trigonidium , and there seems to be no explanation in most literature on the status of this taxon.

The type species Trigonidium cicindeloides is very similar to Metioche Stål, 1877 in that the tympana on fore tibia is generally absent (but not always in Metioche ), the tegmen is not pubescent but differs by exhibiting a range of yellow and black colouration among the congeners (instead of mostly black). The absence of metanotal glands in males, and tegmen rounded in lateral view (not always) (instead of flat) are also characters. Trigonidium also differs from Metioche in the male genitalia ( Fig. 1 ). Until a molecular phylogeny can reveal the phylogenetic relationships of Trigonidium and Metioche , we consider these taxa as separate genera, despite the similarities mentioned above, owing to Metioche lacking in the diagnostic characters of Trigonidium : i.e., distal epiphallic lobes small and immovable in relation to the rest of the epiphallus, rachis with apical spine-like lobule.

There are currently 41 species: 1 from Atlantic Oceanic Islands, 7 Australia and New Guinea, 1 Bolivia, 1 Borneo, 1 China, 2 India, 4 Indian Oceanic Islands, 2 Japan, 2 Java, 4 Madagascar, 1 Malay Peninsula, 3 Pacific Oceanic Islands, 1 Peru, 1 Philippines, 1 Taiwan, 3 central Africa, 3 eastern Africa, and 4 western Africa. It is likely that most species need closer examination to verify their generic statuses and it is likely that Metioche is currently not monophyletic. Metioche (Metioche) pallipes (Stål, 1861) is synoptic with Trigonidium cicindeloides in the former’s type locality, Singapore (Tan, 2012) ( Fig. 1 ). Specifically, the two species co-occur in the grassy areas of Bidadari which is currently cleared for housing development.

Figures

FIGURE 1. Live habitus of Metioche (Metioche) pallipes (Stål, 1861) (A) and Trigonidium cicindeloides Rambur, 1838 (C); male genitalia of Metioche (Metioche) pallipes (B). Scale bar: 0.1 mm.