Tetrigidae

Tetrigidae is an ancient family in the order Orthoptera, which also includes similar families such as crickets, grasshoppers, and their allies. Species within the Tetrigidae are variously called groundhoppers, pygmy grasshoppers, pygmy devils or (mostly historical) "grouse locusts".

Diagnostic characteristics
Tetrigidae are typically less than 20 mm in length and are recognizable by a long pronotum. This pronotum extends over the length of the abdomen, sometimes to the tip of the wings, and ends in a point. In other Orthoptera, the pronotum is short and covers neither the abdomen nor the wings. Tetrigidae are generally cryptic in coloration. Some species have enlarged pronota that mimic leaves, stones or twigs. Other characteristics pygmy grasshoppers exhibit in comparison to other Orthoptera families are the lack of an arolium between the claws, the first thoracic sternite being modified into collar-like structure called sternomentum, a tarsal formula of 2-2-3, scaly fore -wings, and developed hindwings.

General biology
In temperate regions, Tetrigidae are generally found along streams and ponds, where they feed on algae and diatoms. The North American species Paratettix aztecus and Paratettix mexicanus, for example, depend on aquatic primary production for between 80% and 100% of their diet. Riparian species are capable of swimming on the surface of the water, and readily leap into the water when alarmed Some species in the tribe Scelimenini are fully aquatic and capable of swimming underwater.

The highest biodiversity of Tetrigidae is found in tropical forests. Some tropical species are arboreal and live among mosses and lichens in tree buttresses or in the canopy, while others live on the forest floor.

Like other Orthoptera, Tetrigidae have a hemimetabolous development, in which eggs hatch into nymphs. Unlike other temperate Orthoptera, however, temperate Tetrigidae generally overwinter as adults.

Some subfamilies within the Tetrigidae, such as the Batrachideinae, are sometimes elevated to family rank besides the Tetrigidae.

Arulenus miae is a pygmy grasshopper species from the tropical mountainous rainforests of the Philippines. The species was firstly discovered in Facebook post.



Etymology
Origin of the name of the family is not completely clear as there are different sources on its etymology. The name may be derived from Latin tetricus or taetricus, meaning harsh, sour, severe. The name may also originate from the earlier name 'Tettigidae', based on Tettix (synonym of Tetrix), which was preoccupied by Tettigidae (synonym of Cicadidae). Because of the preoccupation by the cicadas' family name, the second 't' in 'tt' was changed into 'r', resulting in the word Tetrigidae.

Subfamilies and Genera
Approximately 2,000 species have been described; according to the Orthoptera Species File the following genera are included:

Subfamily Batrachideinae
Auth.: Bolívar, 1887; selected genera:
 * Batrachidea Serville, 1838
 * Saussurella Bolívar, 1887
 * Tettigidea Scudder, 1862

Subfamily Cladonotinae
Auth.: Bolívar, 1887; selected genera:

Tribe Cladonotini Bolívar, 1887
 * Cladonotus Saussure, 1862
 * Deltonotus Hancock, 1904
 * Piezotettix Bolívar, 1887

Tribe Choriphyllini Cadena-Castañeda & Silva, 2019
 * 1) Choriphyllum Serville, 1838
 * 2) Phyllotettix Hancock, 1902

Tribe Valalyllini Deranja, Kasalo, Adžić, Franjević & Skejo, 2022
 * 1) Lepocranus Devriese, 1991
 * 2) Valalyllum Deranja, Kasalo, Adžić, Franjević & Skejo, 2022

Tribe Xerophyllini Günther, 1979 SE Asia - selected genera:
 * Potua Bolívar, 1887 (genus group)
 * Xerophyllum Fairmaire, 1846

Tribe Unassigned
 * Austrohancockia Günther, 1938
 * Cota Bolívar, 1887
 * Epitettix Hancock, 1907
 * Nesotettix Holdhaus, 1909

Subfamily Lophotettiginae
Auth.: Hancock, 1909
 * Lophotettix Hancock, 1909
 * Phelene Bolívar, 1906

Subfamily Metrodorinae
Auth.: Bolívar, 1887; selected genera: Tribe Amorphopini Günther, 1939
 * Amorphopus Serville, 1838

Tribe Cleostratini Hancock, 1907
 * Cleostratus (insect) Stål, 1877 (Philippines)

Tribe Clinophaestini Storozhenko, 2013
 * Birmana Brunner von Wattenwyl, 1893
 * Clinophaestus Storozhenko, 2013

Tribe Miriatrini Cadena-Castañeda & Cardona, 2015 (monotypic)
 * Miriatra Bolívar, 1906

Tribe Ophiotettigini Tumbrinck & Skejo, 2017
 * Ophiotettix Walker, 1871
 * Uvarovithyrsus Storozhenko, 2016

Tribe Unassigned
 * Bolivaritettix Günther, 1939
 * Cleostratoides Storozhenko, 2013
 * Crimisus (insect) Bolívar, 1887
 * Hildegardia (insect) Günther, 1974
 * Holocerus Bolívar, 1887
 * Macromotettix Günther, 1939
 * Mazarredia Bolívar, 1887
 * Pseudoparatettix Günther, 1937
 * Pseudoxistrella Liang, 1991
 * Vaotettix Podgornaya, 1986

Subfamily Scelimeninae
Auth.: Hancock, 1907 Tribe Scelimenini Hancock, 1907; selected genera: incertae sedis
 * Amphibotettix Hancock, 1906
 * Austrohancockia Günther, 1938
 * Bidentatettix Zheng, 1992
 * Discotettix Costa, 1864
 * Gavialidium Saussure, 1862
 * Scelimena Serville, 1838
 * Zhengitettix Liang, 1994

Subfamily Tetriginae
Auth.: Serville, 1838

Tribe Dinotettigini Günther, 1979
 * Afrocriotettix Günther, 1938
 * Dinotettix Bolívar, 1905
 * Ibeotettix Rehn, 1930
 * Lamellitettix Hancock, 1904
 * Marshallacris Rehn, 1948
 * Pseudamphinotus Günther, 1979

Tribe Tetrigini Serville, 1838
 * Clinotettix Bei-Bienko, 1933
 * Coptotettix Bolívar, 1887
 * Euparatettix Hancock, 1904
 * Exothotettix Zheng & Jiang, 1993
 * Hydrotetrix Uvarov, 1926
 * Paratettix Bolívar, 1887
 * Tetrix Latreille, 1802 (synonym Depressotetrix Karaman, 1960)
 * Thibron Rehn, 1939

Tribe unassigned:
 * Aalatettix Zheng & Mao, 2002
 * Alulatettix Liang, 1993
 * Ankistropleuron Bruner, 1910
 * Bannatettix Zheng, 1993
 * Bienkotetrix Karaman, 1965
 * Bufonides Bolívar, 1898
 * Carolinotettix Willemse, 1951
 * Coptottigia Bolívar, 1912
 * Cranotettix Grant, 1955
 * Ergatettix Kirby, 1914
 * Flatocerus Liang & Zheng, 1984
 * Formosatettix Tinkham, 1937
 * Formosatettixoides Zheng, 1994
 * Gibbotettix Zheng, 1992
 * Hedotettix Bolívar, 1887
 * Leptacrydium Chopard, 1945
 * Macquillania Günther, 1972
 * Micronotus Hancock, 1902
 * Neocoptotettix Shishodia, 1984
 * Neotettix Hancock, 1898
 * Nomotettix Morse, 1894
 * Ochetotettix Morse, 1900
 * Oxyphyllum Hancock, 1909
 * Phaesticus Uvarov, 1940
 * Sciotettix Ichikawa, 2001
 * Stenodorus Hancock, 1906
 * Teredorus Hancock, 1907
 * Tettiella Hancock, 1909
 * Tettiellona Günther, 1979
 * Uvarovitettix Bazyluk & Kis, 1960
 * Xiaitettix Zheng & Liang, 1993

Subfamily Tripetalocerinae
Auth.: Bolívar, 1887 Tripetalocerinae was originally described by Bolívar in 1887 to gather all the Tetrigidae genera of the old world with widened antennae (e.g. Arulenus, Discotettix, Hirrius, Ophiotettix, Tripetalocera). This subfamily today includes only two species in two genera - Tripetalocera (with one species) from India and Borneo and Tripetaloceroides (with one species) from Vietnam and PR China. Members of the subfamily are characteristic within Tetrigidae by massive antennae built up of only eight segments (other Tetrigidae have usually 11-16, Batrachideinae 18-22). Till recently, the subfamily included two tribes - Tripetalocerini and Clinophaestini (including Clinophaestus and Birmana), but the later was moved to the subfamily Metrodorinae due to similarity to Ophiotettigini.


 * Tripetalocera - monotypic Tripetalocera ferruginea Westwood, 1834
 * Tripetaloceroides Storozhenko, 2013 - monotypic Tripetaloceroides tonkinensis (Günther, 1938)

Criotettigini
Auth. Kevan, 1966
 * Criotettix Bolívar, 1887
 * Dasyleurotettix Rehn, 1904

Thoradontini
Auth. Kevan, 1966
 * Eucriotettix Hebard, 1930
 * Loxilobus Hancock, 1904
 * Thoradonta Hancock, 1909

Subfamily and tribe unassigned

 * Bolotettix Hancock, 1907
 * Cyphotettix Rehn, 1952
 * †Eozaentetrix Zessin, 2017
 * Euloxilobus Sjöstedt, 1936
 * Paramphinotus Zheng, 2004
 * Peronotettix Rehn, 1952
 * Phaesticus Uvarov, 1940 (synonym Flatocerus Liang & Zheng, 1984 )
 * Probolotettix Günther, 1939
 * Pseudosystolederus Günther, 1939
 * Syzygotettix Günther, 1938
 * Tettitelum Hancock, 1915
 * †Archaeotetrix Sharov, 1968
 * †Prototetrix Sharov, 1968