Overview
This is a family of medium-sized, cylindrical larviform, wholly subterranean insects comprising six described species; five species occur in Australia, one in New Guinea, and one in Patagonia.
There are two genera,
Cylindracheta
(sandgropers) in Australia and New Guinea, and
Cylindroryctes
in Patagonia. The first is unique in Orthoptera in possessing a thin, tubular, strongly projecting mesothoracic collar, which envelops the hind part of the pronotum, while allowing it free movement in all directions. The insects are found tunnelling in sand in both humid and arid regions.
C. psammophila
sometimes damages wheat in W.A. Two species have been studied cytologically (John and Rentz 1987). In
C. psammophila
2n[male] = 15 (XO) and in
Cylindroryctes spegazzinii
the 2n[male] = 13 (XO).
Description
Eyes reduced, ocelliform. Mandibles and maxillary palps modified for stridulation. Pronotum not overlapping mesonotum, its lateral lobes curving around ventrally and approximated on the mid-ventral line (cf. Gryllotalpidae). Fore femur and tibia greatly flattened and expanded, the latter with very large teeth (dactyls); the tarsus 1- or 2-segmented, slender, without dactyls (cf. Gryllotalpidae). Hind legs not saltatorial; femur scarcely larger than mid femur; tibia short and stout, with stout terminal spurs and no dorsal spines or lamellae. Wings absent. T9 and T10 partly fused; supra-anal plate flexed into a position ventral to T10. Cerci stout, unsegmented, ventral in position, often directed forward. Paraproct without cerciform appendage.