Key to the species of Guiodytes (after Tian 2014, modified)

1. Labrum not or slightly emarginate; pronotum with fore angles not or slightly protruding (Figs 3 A- E); elytral interval three with four or five dorsal setiferous pores, elytral interval five without dorsal setiferous pores (Fig. 4) .................................................................................................................... 2

– Labrum conspicuously emarginate as a semicircular incision; pronotum with fore angles strongly protruding (Fig. 3F); elytral interval three with nine dorsal setiferous pores, elytral interval five with six dorsal setiferous pores (Fig. 4F) (Longzhou: Zhuzhu Dong cave) ............................................... ................................................................................................. G. inexpectatus Tian & Zhou sp. nov.

2. Elytral interval three with four dorsal setiferous pores (Figs 4B, C) ................................................ 3

– Elytral interval three with five dorsal setiferous pores (Fig. 4A, D–E) ............................................ 4

3. Body smaller (5.2 mm); head stouter, labrum seven-setose, palpomeres slightly stouter, antennae shorter and stouter; entire lateral margin of elytra crenulated throughout, striae composed of larger punctures, interval six faintly carinated near base (Fig. 4B) (Longzhou: Paoma Dong cave)............ ........................................................................................................................ G. bedosae Tian, 2013

– Body larger (7 mm); head slender, labrum five-setose, palpomeres slender, antennae longer and more slender; lateral margin of elytra crenulated on basal half, smooth on apical half, striae composed of smaller punctures, interval six strongly carinated near base (Fig. 4C) (Du’an: three caves) ............. ......................................................................................................................... G. cavicola Tian, 2013

4. Body larger (9.2–9.5 mm); frontal carinae long and nearly parallel-sided; pronotum wider than long; elytra with striae smaller and denser punctured, elytral intervals six to eight carinated near base, four and five not carinated (Fig. 4A) ........................................................................................................ 5

– Body smaller and more slender (4.5 mm); frontal carinae short and not parallel-sided; pronotum longer than wide; elytra with striae composed of larger and sparser punctures, elytral intervals six to eight carinated throughout, four and five carinated near base (Fig. 4D) (Huanjiang: Dapo Dong cave) .................................................................................................................................................... ........................................................................................................... G. weii Huang & Faille sp. nov.

5. Body more depigmented, of light brown colour; pronotum shorter and stouter, with remarkably emarginate anterior margin (Fig. 3A); elytral intervals slightly vaulted, elytral striae broad and well marked, with large isolated punctures (Fig. 4A) (Huanjiang: Ji Dong cave, formerly called Shuiku Dong) ......................................................................................................... G. deharvengi Tian, 2014

– Body less depigmented, of reddish-brown colour; pronotum longer and more slender, with anterior margin almost not emarginate (Fig. 3E); elytral intervals rather strongly vaulted, elytral striae narrow and deep, with small isolated punctures (Fig. 4E) (Huanjiang: Huang Dong cave) .......................... ............................................................................................. G. yueliangensis Huang & Tian sp. nov.