1. Larger mesotibial and metatibial apical spurs pectinate (Fig. 1); Body form elongate (Fig. 2). Restricted to western North America (only CA, OR).

(Chaetocanthinae)
Pseudochodaeus
 

1'.

 Larger mesotibial apical spur pectinate, both metatibial spurs simple; Body form oval (Fig. 3). Widely distributed.
2
(Ochodaeinae)
pectinate spur Pseudochodaeus musculus
Fig. 1. Pectinate
apical spur.
Fig. 2. Elongate body form of
Pseudochodaeus estriatus.
Fig. 3. Oval body form of
Xenochodaeus musculus.
 

 

 

 

 

 

 
2. Anterior margin of pronotum not simply concave, instead margin produced behind eyes (Fig. 4). Antenna with 9 antennomeres. Mandibles angulate externally.
 

2'.

 Anterior margin of pronotum simply concave (Fig. 5). Antenna with 10 antennomeres. Mandibles evenly rounded externally.
3

 
Fig. 4. Modified anterior pronotal margin,
Cucochodaeus sparsus
Fig. 5. Concave anterior pronotal margin,
Neochodaeus repandus.
 

 

 

 

 

 

 

 
3. Apex of elytra dentate, teeth interlocking with 2 tubercles on propygidial margin (Fig. 6).
 

3'.

 Apex of elytra not dentate, instead evenly rounded; propygidium lacking tubercles (sulcus may be present on surface).

 

dentate apices
Fig. 6. Dentate (pointed) elytral apices of Parochodaeus spp., with 2 interlocking tubercles on the propygidium.
 

 

 

 

 

 

 

 
4. Propygidium lacking sulcus. Male with mentum strongly produced Antennal club not strongly oval, last segment concave (Fig. 7).
 

4'.

 Propygidium with longitudinal sulcus (Figs. 9-10). Antennal club distinctly oval, last segment convex (Fig. 8).

 

 

Codocera
Fig. 7. Right antenna of
Codocera gnatho, female.
Fig. 8. Right antenna of
Neochodaeus repandus.
 

 

 

 

 

 

 

 

 
5. Propygidium long with elongate, subparallel sulcus (Fig. 9). Mentum distinctly longitudinally impressed from apex to base.
 

5'.

 Propygidium short, with trapezoidal sulcus (Fig. 10). Mentum flat, only weakly impressed apically.

 

propygidium pygidium
Fig.9. Propygidium of
Xenochodaeus spp.
Fig. 10. Propygidium of
Neochodaeus spp.