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 in species group 3
1. Pronotum with two linear depressions composed of united foveolae (note: C. longum Darby, 2019 shows traces on one side of the pronotum of a short depression but is not treated in this section of the key, see below)............................................................................................................................. 2
– Pronotum without linear depressions................................................................................................. 6
2. Posterior corners of mid-keel rounded (Fig. 48C).............................................. C. dewhurst sp. nov.
– Posterior corners of mid-keel with projecting angles ........................................................................ 3
3. Lateral margins of pronotum rounded ............................................................................................... 4
– Lateral margins of pronotum angulate............................................................................................... 5
4. Larger more rounded species...................................................................... C. globulum Darby, 2019
– Smaller, narrower species .................................................................................... C. murphyi sp. nov.
5. Mesoventral mid-keel elongate (Fig. 56C) ........................................................ C. mindanao sp. nov.
– Mesoventral mid-keel square (Fig. 55C) .................................................. C. marshallae Darby, 2019
6. Pronotal disc with only a trace of foveolae .................................................. C. amazonicum sp. nov.
– Pronotal foveolae covering the disc................................................................................................... 7 7. Lateral margins of pronotum angular ................................................................................................ 8
– Lateral margins of pronotum rounded ............................................................................................. 10
8. Mesoventral lateral margins rectangular, hind angles acute.......................... C. longum Darby, 2019
– Mesoventral lateral margins not rectangular .................................................................................... 9
9. Mid-keel very narrow at junction with collar......................................... C. amboroense Darby, 2015
– Mid-keel wide at junction with collar.............................................................. C. puncticolle sp. nov.
10. Elytra almost parallel-sided in posterior half....................................................................................11
– Elytra sinuate in posterior half ........................................................................................................ 12
11. Pronotum densely and finely foveolate (Fig. 54B) ................................................ C. mahleri sp. nov.
– Pronotum sparsely and more coarsely foveolate ................................................... C. werneri sp. nov.
12. Mid-keel not joining collar anteriorly.............................................................................................. 13
– Mid-keel joining collar .................................................................................................................... 14
13. Smaller species length 0.6–0.7 mm, elytra shorter in proportion to pronotum .. C. itoi Sawada, 2008
– Larger species length 0.8 mm, elytra longer in proportion to pronotum ........ C. latum Sawada, 2008
14. Mid-keel almost parallel-sided, hind angles rounded....................................... C. pilosellum sp. nov.
– Mid-keel not parallel-sided.............................................................................................................. 15
15. Mid keel tapering from wide base by collar to keel.................................. C. nomurai Sawada, 2008
– Mid keel otherwise ............................................................................................................................. 16
16. Mid keel with projecting hind angles ........................................................ C. pauxillum Darby, 2019
– Mid keel reduced to small fragments either side of medial extension of the collar ........................................................................................................... C. ikeuchii Sawada, 2008
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 72-73, DOI: 10.5852/ejt.2020.622, http://zenodo.org/record/3777282