Bioacoustics of Paraxantia

Description: Head ovoid, occiput convex and smooth. Fastigium verticis triangular, well-produced, strongly deflexed, dorsally slightly or distinctly sulcate, approximately twice as wide as first segment of antenna, with apex slightly emarginated, nearly touching fastigium frontis. Fastigium frontis triangular, perpendicular. Compound eye elongate, greatly bulging, ventral margin extending through to ventral margin of antennal scrobe ( Figs. 1–5 , 16–25 ). Antennae thread-like, long and flexible. Pronotum gradually tilting and widened backwards; pronotal disk approximately flat, just slightly rough; first transverse groove strongly impressed; second transverse groove more or less indistinct, present before middle with a discontiguous elongate median line extending; lateral carinae finely denticulate on prozona; anterior margin strongly concaved, posterior margin obtuse, with a small middle notch; some small granules composed of two lines, which is shaped into a angle from connection between first transverse groove and each lateral carina to centre of posterior margin ( Figs. 6–10 ). Lateral lobes of pronotum deeper than long; anterior margin with a distinct concavity at top, remainder of anterior margin approximately straight, posterior margin slightly obtuse, ventral margin outspreading backwards, slightly sinuate. Humeral notch distinct, moderate ( Figs. 11–15 ). Tegmen slightly translucent, gradually widened from base, then attenuated behind middle, with regular veinlets; Costa indistinct; subcostal vein and radial vein joined at base, then separated but closely abutted together till before apical part of tegmen; radical sector not bifurcated; apex of tegmen rounded ( Fig. 68 ). Male stridulatory area (Figs. 26–37) with posterior margin straight; male right stridulatory area with distinct mirror. Anterior coxae unarmed. Anterior and median femora with regularly-arranged big spines on ventroanterior margin; posterior femur with many regularly-arranged big spines on ventro-anterior margin and a few big spines near apex on ventro-posterior margin. Anterior tibiae dorsally approximately flat, with tympanum conchate on both sides; widened at and gradually constricted below tympana. Median tibia almost flat, without distinct groove, with or without dorsal spines; posterior tibiae with dorsal spines on both sides. Male terminalia. Tenth abdominal tergum broad, concave in middle ( Figs. 48–49 ). Subgenital plate elongate, with notch at apex; styli minute, robust, short ( Figs. 63–67 ). Male concealed sclerotized genitalia complex, comprising an upper smooth conchae, a median pair of crinkled band-shaped spinous sclerites and a lower pair of denticulate sclerites or a lower unpaired sclerite with bifurcate distal part, which separately enveloped by membranous structures, and arranged from top down in internal genitalia; structure of lower denticulate sclerites distinctly various through different species (Figs. 50–54). Female unknown.

1. Pronotum with posterior margin obtuse, without emargination ( Fig. 65 ); base of posterior tibia is inflated ( Fig. 66 ); tegmen lanceolate, attenuated towards both sides from middle ( Fig. 65 ) Xantia borneensis (Brunner von Wattenwyl) - - Pronotal disk with emarginated posterior margin ( Figs. 6–10 ); posterior tibiae normal ( Fig. 66 ); tegmen not lanceolate, and tapering from behind the middle ( Fig. 68 ) ..................................................................................................... 2 2. Size large (length of tegmen 68.0 mm, length of posterior femur 32.8 mm). Spines on legs strong ( Figs. 66–68 ). Cerci robust, bifurcate at distal third, dorsal one produced inwards and downwards, with basal half gradually tapering, apical half shaped into a sharp spine; ventral one long, produced backwards with ventral margin slightly convex, dorsal margin distinctly concave ( Fig. 55 ).................................................................................... P. tibetensis sp. nov. - - Size small (length of tegmen 55.0–61.1 mm, length of posterior femur 25.0–26.5 mm). Spines on legs much weaker. Cerci robust, bifurcate at apical fourth, dorsal one conical, produced inwards and upwards, with apex rounded; ventral one produced and horizontally inwards, abruptly tapering into a long sharp spine ( Figs. 55–59 ) ........................ 3 3. Stridulatory area with posterior margin slightly sharp angular, greatest width between CuM vein and posterior margin rather large, more than or equal to 5.5 millimeters. Stridulatory file with more than 65 teeth ............................. 4 - - Stridulatory area with posterior margin distinctly obtusely angular, greatest width between CuM vein and posterior margin rather small, less than or equal to 5.0 millimeters. Stridulatory file with less than 50 teeth........................... 5 4. Stridulatory vein straight. Stridulatory file with about 65 widely arranged teeth, most large teeth of equal size except that about 5 basal and 6 apical teeth gradually becoming smaller towards both ends ( Figs.39–40 , 44 ). Unpaired ventral sclerite of phallus with sheet-like upper arm, slightly longer than conical spinous lower arm, notch between lateral lower arm sclerite roundly narrow angular ( Fig. 61 ) ....................................................................... P. s ini ca (Liu) - - Stridulatory vein curved. Stridulatory file with about 73 widely arranged teeth, 22 widely arranged large teeth occupying middle third part, remaining teeth gradually becoming smaller towards both ends ( Figs. 41 , 45 ). Unpaired ventral sclerite of phallus with upper arm shorter than lower one, notch between them sharply angular ( Fig. 62 ) ...................................................................................................................................................... P. hubeiensis sp. nov 5. Radial vein of tegmen with three oblique branches reaching posterior margin beyond radial sector. Stridulatory file with about 55 large teeth of approximately equal size, 27 teeth at apical half widely spaced, remaining 28 teeth sparsely arranged from middle to base ( Figs. 42 , 46 )................................................................. P. parasinica sp. nov. - - Radial vein of tegmen with two oblique branches reaching posterior margin beyond radial sector vein. Stridulatory file composed of 27 distinct teeth, among which apical 13 large teeth of equal size, widely arranged, the remaining 14 teeth gradually becoming smaller and sparsely arranged from middle to base ( Figs. 43 , 47 ) ... P. b i c o r n i s sp. nov.