Trigonidiini Saussure 1874

Tribe Trigonidiini Saussure, 1874 Remarks Trigonidiinae in the Australian region include a number of genera and subgenera that have been giving taxonomists headaches for decades. To start with, the genus Trigonidium was designated with type species Trigonidium cicindeloides from Spain, Europe. The subgenus Trigonidium (Trigonidium) was later proposed by Gorochov (1987). At present, it is doubtful whether all Australian species assigned to Trigonidium actually belong in Trigonidium sensu stricto at all (Tan et al. 2019). Several closely related genera and subgenera were designated based on the presence or absence of auditory tympana on the anterior tibiae and of a stridulatory apparatus in males (Otte & Alexander 1983). Examples are the subgenera Trigonidium (Metioche), Trigonidium (Balamara) Otte & Alexander, 1983, Trigonidium (Parametioche) Otte & Alexander, 1983, and the genus Trigonidomorpha. Because acoustic communication has been lost several times independently in crickets, some of these genera are likely to be polyphyletic (Otte & Alexander 1983: 197; Chintauan-Marquier et al. 2016; Rentz & Su 2019: 316; Tan et al. 2019). To complicate things, different morphs with or without auditory tympana can appear in the same species (Ingrisch 1977; Rentz & Su 2019). It is outside of the scope of this work to resolve the wider systematics of Trigonidiinae in the Australian region. Based on the strong similarities between Trigonidium (Trigonidium) maoricum and Trigonidium (Trigonidium) cicindeloides and on the analysis of molecular data (Fig. 31), I am confident that T. maoricum belongs to the genus Trigonidium s. str. The genus Trigonidomorpha is synonymised here with Trigonidium (Trigonidium).