Cissidium, Motschulsky, 1855, Motschulsky, 1855

Darby, Michael, 2020, A revision of Cissidium Motschulsky (Coleoptera: Ptiliidae) with seventy seven new species, European Journal of Taxonomy 622, pp. 1-188 : 19-21

Key to species in species group 2

1. Species in which the mesocoxal borders are clearly separated ......................................................... 2 – Species with united mesocoxal borders (join sometimes obscured by longer keels) ........................ 8

2. Keel spatulate ( Fig. 37C ) .................................................................................... C. noumeae sp. nov. – Keel narrower, without rounded sides ............................................................................................... 3

3. Keel tapering...................................................................................................................................... 4 – Keel parallel-sided either wholly or in part ....................................................................................... 7

4. Keel smooth, evenly tapering to rounded tip..................................................................................... 5 – Keel rugose either partly or wholly ................................................................................................... 6

5. Anterior angles of mid-keel rounded not reaching collar...................................... C. pinense sp. nov. – Anterior angles of mid-keel broad reaching collar ........................................... C. amieuense sp. nov. 6. Keel setose throughout ....................................................................................... C. mussardi sp. nov. – Keel setose and parallel-sided at base then smooth to tip ................................... C. riparium sp. nov.

7. Keel broad with rectangular tip .......................................................... C. subfoveolatum Darby, 2019 – Keel narrower with slightly rounded tip................................................. C. matthewsi Johnson, 2007

8. Lateral margins of mesoventrite serrate............................................................................................. 9 – Lateral margins of mesoventrite without serrations ........................................................................ 20

9. Elytra without foveolae........................................................................................... C. advena sp. nov. – Elytra with foveolae......................................................................................................................... 10

10. Keel broadening and rounded posteriorly............................................................ C. logunovi sp. nov. – Keel pointed or parallel-sided or tapering posteriorly......................................................................11

11. Pronotal lateral margins with sharp angles medially....................................................................... 12 – Pronotal lateral margins without sharp medial angles..................................................................... 13

12. One pair of pronotal foveae elongate............................................................... C. banari Darby, 2013 – All the pronotal foveae more or less round ............................................................ C. clareae sp. nov.

13. Pronotal sides distinctly concave before hind angles, sides more sharply rounded ( Fig. 28C ) .......... .................................................................................................................... C. inexspectatum sp. nov. – Pronotal sides shallowly concave, almost straight, before hind angles........................................... 14

14. Micropterous species ................................................................................ C. crowsoni Johnson, 1982 – Fully winged or apterous species..................................................................................................... 15

15. Apterous species .............................................................................................................................. 16 – Fully winged species........................................................................................................................ 17

16. Median process of collar long, keel narrow and pointed................................. C. montanum sp. nov. – Median process of collar very short, keel wider................................. C. okuense Grebennikov, 2009

17. Head with a distinct fovea between the eyes ......................................... C. foveolatum Johnson 1982 – Head without a fovea ....................................................................................................................... 18

18. Elytra appearing almost parallel-sided ................................................ C. ishigakiense Sawada, 2008 – Elytral sides more rounded .............................................................................................................. 19

19. Pronotal foveae small, rounded ....................................................................... C. impressum sp. nov. – Pronotal foveae larger two medial ones elongate ...................................... C. aristophanousi sp. nov.

20. Species with only one or two pronotal foveae................................................... C. delicatum sp. nov. – Species with at least four pronotal foveae ....................................................................................... 21

21. Species with a short border along part of the posterior edge of the pronotum................................ 22 – Species without a pronotal posterior border .................................................................................... 23

22. Pronotum with two large basal foveae.......................................................... C. bifoveolatum sp. nov. – Pronotum with four smaller basal foveae ............................................................... C. yoruba sp. nov. 23. Species with straight/almost straight sided mid keel....................................................................... 24 – Species with a clearly concave sided mid-keel................................................................................ 29

24. Posterior angles of mid-keel with carinae to mesocoxal borders ..................... C ceylonicum sp. nov. – Posterior angles of mid-keel without carinae .................................................................................. 25

25. Sides of pronotum straight, parallel-sided before hind angles ............................ C. houailou sp. nov. – Sides of pronotum before hind angles concave ............................................................................... 26

26. Medial process of collar onto mid keel almost reaching to basal tip.................. C. misellum sp. nov. – Medial process of collar onto mid-keel shorter ............................................................................... 27

27. Elytra distinctly foveolate.................................................................................. C. lawrencei sp. nov. – Elytra shallowly foveolate .............................................................................................................. 28

28. Pronotum with eight foveae across the basal margin .............................................. C. rogeri sp. nov. – Pronotum with four foveae across the basal margin................................................ C. deanei sp. nov.

29. Sides of pronotum sharply angled ................................................................................................... 30 – Sides of pronotum rounded or with faint angle ............................................................................... 31

30. Mid-keel broad, medial extension of collar reaching to raised posterior margin of mid-keel ............ ............................................................................................................................ C. robustum sp. nov.

– Medial extension of collar very short/effaced not reaching posterior margin of mid-keel ................. ......................................................................................................................... C. greensladei sp. nov.

31. Keel long, parallel-sided, without pubescence ....................................... C. scutellaris ( Deane, 1931) – Keel pubescent................................................................................................................................. 32

32. Front angles of mid-keel not reaching collar, keel sharply pointed.................. C. davaoense sp. nov. – Keel narrow, parallel-sided, foveolate ............................................................... C. lamington sp. nov.

Figures

Fig. 37. Cissidium noumeae sp. nov. A. Habitus. B. Pronotum, × 547. C. Mesoventrite showing median process of collar, mid-keel and keel, × 760.

Fig. 28. Cissidium inexspectatum sp. nov. A. Habitus. B. Pronotum, × 660. C. Mesoventrite showing median process of collar, mid-keel and keel, × 1120.