A Review of the Genus Alulatettix Liang (Orthoptera: Tetrigoidea: Tetrigidae)

The taxonomy of the tetrigid genus Alulatettix Liang is reviewed. A new species, Alulatettix orthomarginalis n. sp. is described. The annotated list and key to all known species of Alulatettix are given.

In this paper, the genus of Alulatettix Liang is systematically revised and we include the clarification of the taxonomic status of the genus Alulatettix and determine the characters for species diagnosis. Information on biology and geographical distribution are also added, we describe Alulatettix orthomarginalis n. sp. and provide an updated key to the species.
Description. Body size small, with small granules. Vertex protruding beyond anterior margin of eyes, with median carina. Vertex about 1.5-2.0 times as wide as an eye. Frons oblique, frontal costa slightly concave between lateral ocelli and protruding between the base of antennae in profile, longitudinal groove on frontal costa as wide as 1st antennal segment. Lateral ocelli situated middle of anterior margin of eyes. Eyes spherical. Pronotum distinctly tectiform, median carina, lateral carinae, and humeral angles of pronotum well defined; apex of hind process rounded or with triangular concavity; posterior margins of lateral lobes of pronotum with two concavities. Elytra and wings brachypterous. Fore and mid femora with nearly straight or wave-like ventral margin. First segment of hind tarsi longer than the third.
Key to the species of Alulatettix Liang   Alulatettix fornicata (Ichikawa) Tetrix fornicatus (Ichikawa 1993, p. 2; holotype-female, Japan: Hatsutani Mts; in OMNH Osaka); A. fornicata (Ichikawa, 1993;Zheng and Zhong 2001, p.197 Alulatettix orthomarginalis n. sp. (Figs 1-3, 4-11, 12) Description Female. (Fig 1) Size small. Head not projecting above upper level of pronotum (Fig 4). Anterior margin of vertex curved (Fig 2), slightly protruding beyond eyes, median carina conspicuous, the vertex between eyes 1.6 and 1.7 times wider than width of one eye from above. Vertex and frontal ridge curved in profile, frontal ridge concave between lateral ocelli (Fig 3), frontal ridge protruding archly between antennae, width of longitudinal furrow equal to width of first segment of antennae (Fig 5). Antennae filiform (Fig 6), 15 segmented, situated between lower margin of eyes (Figs 3-6), the eighth segment about five times as long as wide. Eyes globular. Lateral ocelli placed between middle of anterior margins of eyes (Figs 2 and 3). Pronotum in dorsal view tectiform, anterior margin obtuse angular (Fig 2), dorsal margin arched in profile (Figs 1 and 3). Posterior process of pronotum short, just reaching two thirds of hind femora, apex of process triangularly incised in middle (Fig 2). Lower margin of hind process straight (Figs 1 and 3), lateral carinae in metazona straight. Lateral carinae in prozona inconspicuous, parallel; humeral angle obtuse. Posterior margin of lateral lobes in lateral view with two concavities (Fig 3), the first extremely shallow; posterior angles of lateral lobes of pronotum turned downwards, with rounded apex. Tegmina smaller, brachypterous (Fig 8), elliptic, visible part of tegmen 3.5 times as long as wide. Hind wings strongly reduced as strips (Fig 8), just reaching the posterior margin of 1st segment of abdomen, in lateral view slightly exposed by the pronotum. Ventral margins of fore and mid femora slightly undulating (Fig 7); mid femur 2.0 times wider than visible part of tegmen. Hind femora stout, 3.0 times as long as wide; dorsal and ventral side of femora gentle dentate; pregenicular spine rectangular; genicular spine acute. Outer side of hind tibia with seven or eight spines, inner side with eight or nine spines. First segment of hind tarsi 1.6 times longer than the third segment; third pulvillus of first tarsus longer than first or second, apices of the first and the second pulvilli sharp, apex of the third pulvillus rectangular. Ovipositor narrow and long: upper valve 3.0 times as long as wide, upper and lower valves with slender saw-like teeth (Fig 9). Length of subgenital plate slightly less than its width; posterior margin of subgenital plate triangularly projecting (Fig 10).
Body dark brown, with a pair of dark spots behind shoulders (Fig 2). Hind tibia dark brown.
Male. (Fig 12) Size in males slightly smaller than in females. Vertex between eyes 1.4 and 1.5 times wider than width of one eye from above, subgenital plate short, cone-shaped (Fig 11). Other structures and coloration same as female.

Diagnosis
Alulatettix orthomarginalis is similar to A. wufengensis and A. chuxiongensis from which it differs in the vertex and frontal ridge curved in profile, the width of longitudinal furrow of frontal ridge equal to width of the first segment of antennae, the lower margin of hind process straight, the midfemur 2.0 times wider than the visible part of tegmen, and in the triangularly projecting posterior margin of female subgenital plate.
Etymology. The species name is derived from the Latin ortho and marginis, meaning lower margin of hind process straight.
Distribution. People's Republic of China, Guizhou.

Discussion
The original description of the genus was exclusively based on characters from external morphology. The morphology of Alulatettix is quite homogeneous and species can be differentiated mostly by the brachypterous elytra and wings. Recent molecular studies based on A. qinlingensis cytochrome oxidase I (Fang et al 2010) demonstrated Alulatettix to be closely related to the genus Tetrix Latreille. Alulatettix and Tetrix belong to the subfamily Tetriginae, and both of these genera are similar in the head not projecting above upper level of pronotum and the posterior margin of lateral lobes in lateral view with two concavities, but they differ in the shape of pronotum and degree of development of tegmina and hind wings. Tetriginae are one of the most basal members of Tetrigoidea, but the phylogenetic studies focusing on the relationships within Tetriginae are limited. Therefore, phylogenetic relationships between Alulatettix and other Tetriginae genera are not well understood.
Species of the genus Alulatettix are usually associated with, but not limited to, shady environments, living under fallen leaves or grasses in tropical rainforests. Some (Mao et al 2011) have suggested that the brachypterous hind wings are not adapted for flying. The diet is consisted mainly of algae growing on moist ground, along with lichens and some forms of humus. Species of Alulatettix generally overwinter as adults. Almost all species of Alulatettix are distributed in the Oriental region, except one species known from the east part of the Palaearctic region (Japan: Honshu Island; Zheng 2012).