Xistra Bolivar, 1887

Zheng, Zhe-Min & Zeng, Hui-Hua, 2011, A review of the genus Xistra Bolivar 1887 (Orthoptera: Tetrigidae) with description of two new species, Journal of Natural History 45 (31 - 32), pp. 1895-1904 : 1896-1899

Xistra Bolivar, 1887

Xistra Bolivar 1887, p. 242 ; Kirby, 1910: 27; Kirby, 1914: 55; Hancock, 1915: 102; Günther, 1939: 159–160; Liang and Zheng, 1988: 102; Shishodia, 1991: 103–105; Zheng, 2005a: 129–132; Zheng, 2005b: 124; Zheng, 2009: 297.

Type species: Xistra gogorzae Bolivar, 1887 , by subsequent designation ( Kirby, 1910).

Differential diagnosis

This genus is similar to Chiriquia Morse, 1900 , the genus Xistrella Bolivar, 1909 , but differs from the three latter genera by the vertex, seen from the front, appearing as an acute triangular excision between the eyes.

Key to the genera closely related to Xistra

1. Vertex, seen from the front, appearing as an acute triangular excision between the eyes, with vertex protuberances reaching high above the eyes. Distribution in Philippines, China, Nepal................................ Xistra Bolivar

Vertex normal, usually sunken between the eyes, when seen from the front not appearing as an acute triangular excision, vertex protuberances can be present................................................................. 2

2. The anterior and mid-femora with toothed protuberances or at least very distinctly wavy, always with more or less elevated humps in their anterior halves. Surface of the pronotum usually also with roughnesses. Distribution in South America................................................. Chiriquia Morse

The anterior and mid-femora with only slightly wavy, or almost straight, smooth, carinae; pronotum surface smooth, median carina only rather seldom raised in profile to a regularly arched hump; somethimes with distinct, rarely very long, vertex teeth.............................................3

3. The lateral carenae of the vertex (fastigium) becoming obsolete immediately behind or at the corners of the leading edge, so that the vertex seems abnormally to lack the usual lateral carenae; these are at their hindmost end often extended upwards into more or less distinct but rarely very long vertex protuberances; frontal ridge and median carena of vertex usually indistinct; antennae inserted distinctly below the eyes, leaving a clear gap below them, and usually remarkably long. Distribution in Sri Lanka, India, Palawan, Sulawesi, China.......................................... Xistrella Bolivar

The lateral carenae of the fastigium of substantial length, and, like its median carena, well-developed; vertex protuberances absent. Frontal carena throughout its length and the leading edge of the vertex in true profile clearly visible in front of the eyes. Distribution in Taiwan............. Xistrellula Günther

Composition

Fifteen species distributed in the Philippines, Nepal and China.

Key to the species of Xistra Bolivar

1. Head in frontal view with vertex forming “V”-shaped, deep concavity..... 2

Head in frontal view with vertex forming “U”-shaped concavity........... 6

2. “V”-shaped concavity deeper, bottom of which reaching middle of inner margins of eyes; in profile, upper margin of pronotum distinctly protruding before shoulders, behind forming a concavity. Distribution in Philippines: Camarines South, Libmanan....................... Xistra gogorzae Bolivar

“V”-shaped concavity shallow, bottom of which reaching one-third of upper inner margins of eyes....................................................3

3. In profile, upper margin of pronotum nearly straight...................... 4

In profile, upper margin of pronotum with 1–2 projections................ 5

4. Width of vertex nearly equal to width of eye; antennae inserted far below lower margin of eyes; width of mid femur wider than width of tegmina; hind tibia black; ventral thorax and abdomen brown. Distribution in China: Guangxi (Longzhou)................... Xistra nigritibialis Zheng and Jiang

Width of vertex extremely narrower than width of eye (0.71:1); antennae inserted in just lower margin of eyes; hind tibia white; ventral thorax and abdomen black. Distribution in China: Yunnan (Pu’er)....................

..................................................... Xistra parvula Liang

5. In profile, upper margin of pronotum with two projections; antennae inserted between lower margins of eyes; lateral keels of prozona constricted backward; hind tibia black-brown; ventral thorax and abdomen bright black. Distribution in China: Yunnan (Yuanjiang)........................................................................ Xistra strictivertex Zheng and Ou

In profile, upper margin of pronotum with one projection before shoulders; antennae inserted far below lower margin of eyes; lateral keels of prozona parallel; hind tibia brown; ventral thorax and abdomen brown. Distribution in China: Yunnan (Pu’er)............................ Xistra foliolata Liang

6. Width of vertex equal to width of eye.................................... 7

Width of vertex narrower than width of an eye........................... 8

7. Pronotum with a pair of short, longitudinal keels between shoulders; lateral ocelli placed in between lower margins of eyes; hind tibia yellow-brown. Distribution in China: Xizang (Motuo).............. Xistra laticorna Zheng

Pronotum without a pair of short, longitudinal keels between shoulders; lateral ocelli placed in the lower one-third of anterior margin of eyes; hind tibia with three black rings. Distribution in China: Guangxi Tianlin)............................................... Xistra longidorsalis Liang and Jiang

8. In profile, upper margin of pronotum straight or slightly protruding before shoulders; hind wing not reaching or reaching top of hind process......... 9

In profile, upper margin of pronotum with two hill-shaped bulges or comb shape before shoulders; hind wing surpassing top of hind process........ 13

9. Width of frontal ridge between antennae wider than or equal to width of first segment of antennae; with a pair of short, longitudinal keels between shoulders.............................................................. 10

Width of frontal ridge between antennae narrower than width of first segment of antennae; without a pair of short longitudinal keels between shoulders.............................................................. 11

10. Width of frontal ridge between antennae wider than width of first segment of antennae; with a pair of short longitudinal keels between shoulders; lateral margin with a pair projections after shoulders; hind process reaching middle of hind tibia; hind tibia brown. Distribution in China: Guangxi (Longzhou)

..................................... Xistra longzhouensis Zheng and Jiang

Width of frontal ridge between antennae equal to width of first segment of antennae; with a pair of long and oblique longitudinal keels between shoulders; lateral margin without a pair of projections after shoulders; hind process surpassing top of hind tibia; hind tibia black with two white bands. Distribution in China: Yunnan (Ruili).............. Xistra klinnema sp. nov.

11. Lateral ocelli placed in the lower one-third of anterior margin of eyes; hind wing reaching top of hind tibia; hind tibia black......................... 12

Lateral ocelli placed in between lower margins of eyes; hind wing not reaching top of hind process; hind tibia yellow-brown. Distribution in China: Xizang (Motuo)......................................... Xistra medogensis Zheng

12. In profile, upper margin of pronotum slightly protruding before shoulders; width of mid femur equal to width of tegmina; ventral thorax and abdomen black. Distribution in China: Sichuan (Ya’an)....... Xistra yaanensis Zheng

In profile, upper margin of pronotum distinctly protruding before shoulders; width of mid femur distinctly narrower than width of tegmina; ventral thorax and abdomen brown. Distribution in China: Jiangxi (Jiulianshan)..........

..................................... Xistra jiulianshanensis Zheng and Shi

13. In profile, upper margin of pronotum with two hill-shaped bulges before shoulders; lateral margin of frontal ridge nearly parallel; body surface with small particles......................................................... 14

In profile, upper margin of pronotum forming comb shape before shoulders; lateral margin of frontal ridge upper narrower, lower broader; body surface

with big tubercles. Distribution in Nepal: Nuwakot Dist...................

................................................ Xistra longicornis Ingrisch

14. Anterior margin of vertex slightly protruding before eyes; frontal ridge slightly protruding between eyes; hind process reaching one-third of hind tibia; hind wing reaching or surpassing top of hind tibia. Distribution in Nepal: Taplejung / Terhathum Dist.................. Xistra angusta Ingrisch

Anterior margin of vertex not protruding before eyes; frontal ridge distinctly protruding between eyes; hind process reaching top of hind tibia; hind wing only reaching basal part of hind tibia. Distribution in China: Fujian (Wuyishan)................................... Xistra wuyishanensis sp. nov.