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 "grouse locusts".

Diagnostic characteristics

Tetrigidae are typically less than 20 mm in length, and are recognizable by a long pronotum, that 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 lack of arolium between the clows, first thoracic sternite modified into collar-like structure called sternomentum, tarsal formula 2-2-3, scaly fore wings, and developed hind wings.

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

The name may be derived from Latin tetricus or taetricus, meaning harsh, sour, severe.

Subfamilies and Genera

Approximately 1,900 species have been described; according to the Orthoptera Species File the following genera are included:

Subfamily [Batrachideinae]

Auth.: Bolívar, 1887
Auth.: Bolívar, 1887
Auth.: Hancock, 1907
Tribe Discotettigini Hancock, 1907
Tribe unassigned
Auth.: Hancock, 1909
Auth.: Bolívar, 1887; selected genera:
Tribe Amorphopini Günther, 1939
Tribe Cleostratini Hancock, 1907
Tribe Clinophaestini Storozhenko, 2013
Tribe Miriatrini Cadena-Castañeda & Cardona, 2015
Tribe Ophiotettigini Tumbrinck & Skejo, 2017
Tribe Unassigned
Auth.: Hancock, 1907
Tribe Criotettigini Kevan, 1966
Tribe Scelimenini Hancock, 1907
Tribe Thoradontini Kevan, 1966
Tribe unassigned:
Auth.: Serville, 1838
Tribe Dinotettigini Günther, 1979
Tribe Tetrigini Serville, 1838
Tribe unassigned:
Auth.: Bolívar, 1887
Tripetalocerinae was originally described by Bolívar in 1887 to gather all the Tetrigidae genera of the old world with widened antennae. This subfamily today includes only fwo species in two genera - Tripetalocera from India and Borneo and Tripetaloceroides from Vietnam and PR China. Members of the subfamily are characteristic within Tetrigidae by massive antennae built up of only eight segments. Till recently, the subfamily included two tribes - Tripetalocerini and Clinophaestini, but the later was moved to the subfamily Metrodorinae due to similarity to Ophiotettigini.
Tribe Xerophyllini Günther, 1979
Subfamily and tribe unassigned: