Taxonomy and morphological characterization of Allotettix simoni (Bolívar, 1890) and implications for the systematics of Metrodorinae (Orthoptera: Tetrigidae)

Abstract

Characters used to diagnose the subfamily Metrodorinae (Bolívar, 1887) (Orthoptera: Tetrigidae) are largely variable or homoplastic. Relevant traits used to distinguish amongst subfamilies of Tetrigidae, including sensorial structures, mouth parts, and genitalia are not present in any description of representatives of the subfamily Metrodorinae. The identity of Metrodorinae remains thus at stake. Aiming to fill the current lack of knowledge, a complete anatomical description of adult and last instar nymphs of Allotettix simoni (Bolívar, 1890) is provided. Allotettix simoni is a controverted taxon, originally described in the genus Paratettix and subsequently synonymized with Allotettix peruvianus. The revision of type specimens revealed that A. simoni and A. peruvianus are different species. As neither keys nor descriptions of nymphs of Neotropical Tetrigidae exist, A. simoni nymphs were identified comparing mitochondrial sequences of the cytochrome c oxidase subunit I (COI) gene with adult specimens. The anatomical description of A. simoni expanded by comparisons with material of Metrodora sp. nov., revealed that the subfamilies Metrodorinae and Tetriginae are morphologically very similar, whereas molecular analyses of the COI data set do not support the monophyly of the subfamily Metrodorinae with respect to Tetriginae. Consequently Metrodorinae might not represent an independent entity with respect to Tetriginae.

Mitochondrial genomes of eight Scelimeninae species (Orthoptera) and their phylogenetic implications within Tetrigoidea

“…All trees showed Trachytetix bufo and Yunnantettix bannaensis did not form one sister group for Cladonotinae. Our results supported the previous finding that Metrodorinae and Cladonotinae were not monophyletic groups ( Yao, 2008 ; Pavon-Gozalo, Manzanilla & Garcia-Paris, 2012 ; Lin et al, 2015 ). As only two species were included in the subfamilies, more samples are needed to uncover these relationships.…”

Taxonomic and biogeographic revision of the genus Lamellitettigodes (Orthoptera: Tetrigidae) with description of two new species and additional notes on Lamellitettix, Probolotettix, and Scelimena

“…This was the main character used when the subfamily was established by Bolívar (1887), and Günther also adopted it. Today, typically Metrodorinae are mainly characterized by having the median ocellus and the antenna placed below the eyes, a relatively small divergence of the rami of the frontal costa not forming wide scutellum, and a similar length of the first and third segments of the hind tarsus (Pavón-Gonzalo et al 2012). Many species of Metrodorinae also exhibit the posterior angles of the lateral lobes of the pronotum produced outwards, often becoming acutely spinose.…”

Oriental macropterous leaf-mimic pygmy grasshoppers—genera Oxyphyllum and Paraphyllum (Orthoptera: Tetrigidae) and their taxonomic assignment

“…Other Metrodorinae groups (e.g. Malagassy and South American) are not assessed here because it was already shown that Metrodorinae represents a 'garbage can', a polyphyletic group made for easier identification of macropterous Tetrigidae with uncertain placement (Pavón-Gonzalo et al 2012). Metrodorinae are often defined as a group of genera with antennae with 11-16 segments, filiform antennae without widened segments (there are numerous exceptions from this), narrow scutellum (also numerous exceptions exist), lateral pronotal lobes directed sidewards and not having acute spines (also a character with numerous exceptions).…”