Key to the species of Urodeta based on male genitalia*

1. Spinose knob of gnathos reduced (Koster & Sinev 2003, fig. 54)...................................... U. hibernella

- Spinose knob of gnathos well developed, armed with spines directed cephalically................................. 2

2. Sacculus entirely separated from remaining valva as an elongate lobe........................................... 3

- Sacculus not separated from remaining valva.............................................................. 4

3. Valva divided into two separate lobes (sacculus and remaining part of valva); phallus not dilated basally (Sruoga & De Prins 2011, figs 25–28)............................................................................. U. acerba

- Valva divided into three distinct lobes (sacculus entirely separated and termen of remaining part of valva deeply emarginated so appear divided into long and narrow lobes); phallus strongly dilated basally (figs 22, 23)................. U. trilobata

4. Ventral margin of sacculus partly serrated (Sruoga & De Prins 2011, figs 52–55)........................... U. crenata

- Ventral margin of sacculus not serrated................................................................... 5

5. Spinose knob of gnathos divided into two separated lobes (Sruoga & De Prins 2011, figs 39–41).............. U. bucera

- Spinose knob of gnathos not divided..................................................................... 6

6. Inner processes of valvae fused apically and embedded with many small cusp-shaped spines (Sruoga & De Prins 2011, figs 15–20)..................................................................................... U. absidata

- Valva without inner process embedded with spines.......................................................... 7

7. Phallus with strongly sclerotized narrow streak along ventral margin........................................... 8

- Phallus without strongly sclerotized narrow streak along ventral margin........................................ 10

8. Distal margin of juxta deeply indentated, with two distinct, sclerotized lobes (Sruoga & De Prins 2011, figs 35, 36)................................................................................................... U. aculeata

- Distal margin of juxta not indentated and without distinct lobes................................................ 9

9. Valvae are tightly fused together dorso-proximally; vesica with two clusters of large cornuti (12–15 and 12–16) and with sev- eral minute spines (Sruoga & De Prins 2011, figs 74–76)................................................ U. talea

- Valvae not fused together dorso-proximally; vesica with one cluster of 4 large cornuti and with several minute spines (Mey 2007, figs 33, 34)........................................................................... U. maculata

10. Vesica without cornuti (Kaila 2011, fig. 97)..................................... U. sp. reared from Terminalia sp.

- Vesica with cornuti.................................................................................. 11

11. Phallus distally tapered to pointed apex.................................................................. 12

- Phallus distally not tapered to pointed apex............................................................... 14

12. Vesica with one large cornuti and with group of minute spines (Sruoga & De Prins 2011, figs 58–63).......... U. cuspidis

- Vesica with more than one large cornuti and can be with group of minute spines................................. 13

13. Costa shorter than spinose knob of gnathos; spinose knob of gnathos rounded (Kaila 2011, fig. 95).............. U. inusta

- Costa at least twice longer than spinose knob of gnathos; spinose knob of gnathos wider than long (Sruoga & De Prins 2009, figs 37–40).................................................................................. U. gnoma

14. Phallus 7 times longer than wide; vesica with one large cornuti (Mey 2007, figs 35, 36).................... U. taeniata

- Phallus 4–5 times longer than wide; vesica with few large cornuti and many tiny spines........................... 15

15. Ventral shield of juxta with distinct apically rounded lobes; sacculus very short, less than length of spinose knob of gnathos; vesica with 6 large cornuti and numerous tiny spines (Sruoga & De Prins 2009, figs 50, 51)................... U. tantilla

- Ventral shield of juxta without distinct lobes; sacculus long, at least twice longer than length of spinose knob of gnathos; vesica with two rows of large cornuti (4–5 in each row) and numerous tiny spines (Sruoga & De Prins 2009, figs 44–47)................................................................................................... U. spatulata