Key to species of Bittacidae in Guizhou

1. Male tergum X completely absent. Epandrial appendages prominently shorter than half length of gonocoxites; acute tooth protrusion on ventral margin subbasally ....... T. xiphicus Tan & Hua, 2009

− Male tergum X degenerate more or less into two slender lateral plates. Epandrial appendages approximately equal to or longer than half length of gonocoxites; no denticulate protrusion on ventral margin ............................................................................................................................................... 2

2. One pale streak on meso- and metanotum ........................................................................................ 3

− No obvious streak on meso- and metanotum .................................................................................... 4

3. Wings tinged with light yellowish brown, without markings except pterostigma; Pcv one ............... ........................................................................................................... B. falcatus Zhou & Zhou, 2007

− Wings tinged with yellowish brown or blackish brown, with numerous markings, Pcv two ........... 5

4. Sc ending beyond FRs and FM, Av one, without nygmata; upper branch of proctiger slender, male cerci slender ...................................................................... B. kuankuoshuensis Zhou & Zhou, 2012

− Sc ending before FRs and FM, no Av, nygmata at median of wings; upper branch of proctiger expanded distally, male cerci clavate ................................................................................ B. multisetus sp. nov.

5. Wing with large darkish brown marking from Sc to A1 ending .... B. stigmosus Zhou & Zhou, 2005

− Wing with small discrete flecks ........................................................................................................ 6

6. Wings with four conspicuous markings at OM, ORs, FRs and CuP ending, respectively ................. .................................................................................................... B. dashahensis Zhou & Zhou, 2005

− Wings with more or less markings .................................................................................................... 7

7. Epandrial appendages subquadrangular in lateral aspect, straight on ventral and dorsal edges, without protrusions or long setae .................................................................................. B. sinicus Issiki, 1931

− Epandrial appendages irregularly shaped in lateral aspect, crooked on ventral or dorsal margins, with protrusions or long setae ................................................................................................................... 8

8. Epandrial appendage with row of long blackish brown setae on ventral margin ............................... ........................................................................................................... B. setigerus Chen & Hua, 2013

− Epandrial appendage without setae on ventral margin ..................................................................... 9

9. Epandrial appendages greatly elongated into paired long sinuous lobes ........................................... ................................................................................................................. B. leigongshanicus sp. nov.

− Epandrial appendages not elongated .............................................................................................. 10

10. Caudal portion of gonocoxites with paired lobes ................................................. B. dilobus sp. nov.

− Caudal portion of gonocoxites with V-shaped membrane ....................................... B. lii Zhou, 2003