Cissidium Motschulsky 1855
Creators: name: Darby, Michael
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Ptiliidae
Cissidium

description: Key to species group 4B
1. Mesoventral lateral margins serrate................................................................................................... 2
– Mesoventral lateral margins without serrations................................................................................. 6
2. Pronotum lateral margins angulate .................................................................................................... 3
– Pronotum lateral margins rounded..................................................................................................... 4
3. Pronotum lateral margins less strongly angled, almost parallel-sided before hind angles, wider than the elytral base ......................................................................................... C. cryptophagoides sp. nov.
– Pronotal base narrower with two linear depressions, sides strongly angled ....................................... .................................................................................................................... C. shibatai Sawada, 2008
4. Elytra narrow, pronotum lateral margins almost parallel-sided base without linear depressions........ ........................................................................................................................ C. sakaii Sawada, 2008
– Elytra rounded ................................................................................................................................... 5
5. Mid-keel wider anteriorly ...................................................................... C. nishikawai Sawada, 2008
– Mid-keel wider posteriorly .................................................................... C. elongatum Sawada, 2008
6. Mesoventral lateral margins partly or completely effaced .............................................................. 15
– Mesoventral lateral margins distinct to mesocoxal borders............................................................... 7
7. Mesoventral collar without a median extension ................................................ C. obsoletum sp. nov.
– Mesoventral collar with a median extension ..................................................................................... 8
8. Mesoventrite lateral margins with a distinct concave bulge at the posterior angle ........................... 9
– Mesoventral lateral margins without a concave bulge..................................................................... 14
9. Mid-keel not fusing with the posterior border of the mesoventral collar the anterior angles not interrupting the line of the posterior margin................................................................................... 10
– Mid keel fusing with the posterior border of the mesoventral collar ...............................................11
10. Raised posterior margin before keel broad and strongly sculpted..................... C. ibicarense sp. nov.
– Raised posterior margin before keel narrower not sculpted ............................. C. peruviense sp. nov.
11. Larger species ± 0.90 mm ......................................................................................... C. orami sp. nov.
– Smaller species ± 0.65–0.70 mm ..................................................................................................... 12
12 Mesoventral lateral margin hind angle sharp the concave extrusion very small................................. ................................................................................................................................. C. dybasi sp. nov.
– Mesoventral lateral margin hind angle more rounded..................................................................... 13
13. Mid-keel broad, short, mesoventral collar extension short .................... C. reitteri (Matthews, 1889)
– Mid keel narrower, longer, mesoventral collar extension longer ....................... C. bomjesus sp. nov.
14. Mid-keel very much reduced almost absent, keel strongly sculpted ................... C. losbanos sp. nov.
– Keel narrow before joining keel, less strongly sculpted................................ C. sawadai Darby, 2015
15. Keel very broad, flat, with rounded tip .............................................................. C. similatum sp. nov.
– Keel narrower .................................................................................................................................. 16
16. Mid-keel sides strongly widened anteriorly .................................................................................... 17
– Mid-keel sides not so widened anteriorly, sides concave ................................................................ 19
17. Posterior margins of humeri very long ............................................................................................ 18
– Posterior margins of humeri shorter, mid-keel with concave sides .................................................... ............................................................................................................... C. basale Motschulsky, 1855
18. Longer species, mid-keel wider........................................................................... C. lisae Darby, 2015
– Shorter species, mid keel shorter, keel much narrower ................................... C. tigrum Darby, 2015
19. Mid-keel hind angles rounded ........................................................................... C. obscenum sp. nov.
– Mid-keel hind angles not rounded, extending towards mesocoxal posterior border....................... 20
20. Mesoventral collar without a medial extension .................................................. C. dividuum sp. nov.
– Mesoventral collar with a medial extension .................................................................................... 21
21. Mesoventral median extension long, with a splayed end, keel very long and narrow ........................................................................................................ C. subangulatum sp. nov.
– Shorter species, mid-keel shorter, keel shorter and wider at base ................... C. angulatum sp. nov.
description: Published as part of Darby, Michael, 2020, A revision of Cissidium Motschulsky (Coleoptera: Ptiliidae) with seventy seven new species, pp. 1-188 in European Journal of Taxonomy 622 on pages 137-138, DOI: 10.5852/ejt.2020.622, http://zenodo.org/record/3777282