Key to Genera in the Subfamilies Diamesinae, Prodiamesinae, Podonominae and Orthocladiinae

Recommended Citation:
Walker, I. R., 1997. Key to genera in the subfamilies Diamesinae, Prodiamesinae, Podonominae and Orthocladiinae Part III. In: I. R. Walker (Ed.), The WWW Field Guide to Subfossil Midges. (http://www.sci.ouc.bc.ca/fwsc/iwalker/chironomid/orthocladiinae/orthkey3.htm)

Last Update: 11 June 1997

©1997 Ian R. Walker. ALL RIGHTS RESERVED

1. • a) Ventromental plates completely overlapping all pairs of lateral teeth (Fig. 1)
     .............................................................................Potthastia?
     
     
   • b) Ventromental plates smaller, some lateral mental teeth may extend beyond anterior ventromental margin of flattened head capsule (Fig. 2)
     .............................................................................2.
   
   
   
   
2. • a) Ventromental plates wholly or partially overlapping some mental teeth, with approximately straight or weakly concave antero-lateral margins; median tooth dark; premandible simple (Fig. 2)
     .............................................................................Psectrocladius (Monopsectrocladius) type
     
     
   • b) Ventromental plates not overlapping mental teeth (Fig. 4); or if wholly or partially overlapping mental teeth, then anterolateral margin convex, or median tooth with little or no pigmentation; premandible simple or compound (Fig. 8)
     .............................................................................3.
   
   
   
   
3. • a) Ventromental plates very broad in submental region (Fig. 3).
     .............................................................................Stilocladius
     
     
   • b) Ventromental plates not exceptionally broad in submental region (Fig. 6)
     .............................................................................4.
   
   
   
   
4. • a) Median tooth flanked by 2 pairs of light-coloured lateral teeth (Fig. 4)
     ............................................................................."Cricotopus" type
     
     
   • b) Median tooth flanked by 1 pair of light-colured lateral teeth, or all lateral teeth similarly pigmented (Fig. 5)
     .............................................................................5.
   
   
   
   
5. • a) Median tooth weakly notched laterally (Fig. 5)
     .............................................................................Parakiefferiella sp. B
     
     
   • b) Median tooth unnotched (Fig. 6)
     .............................................................................6.
   
   
   
   
6. • a) Second lateral teeth distinctly smaller than adjacent teeth (but 1st and 2nd lateral teeth absent when mouthparts strongly worn); median tooth as dark as lateral teeth (Fig. 6)
     .............................................................................Parakiefferiella nigra
     
     
   • b) Second lateral teeth of similar size to adjacent pairs; median tooth with light or dark pigmentation (Fig. 9)
     .............................................................................7.
   
   
   
   
7. • a) Median tooth very broad and with little, if any, pigmentation (Fig. 9).
     .............................................................................8.
     
     
   • b) Median tooth less broad, with distinct pigmentation (varying from pale yellow or tan to dark brown) (Fig. 7)
     .............................................................................Smittia/Pseudosmittia type
   
   
   
   
8. • a) Median tooth strongly arched (Fig. 8).
     .............................................................................Parakiefferiella triquetra type
     
     
   • b) Median tooth weakly arched (Fig. 9)
     .............................................................................Paracladius type
   
   
   
   

Fig. 1. Potthastia?.

Fig. 2. Psectrocladius (Monopsectrocladius)

Fig. 3. Stilocladius.

Fig. 4. "Cricotopus" type.

Fig. 5. Parakiefferiella sp. B.

Fig. 6. Parakiefferiella nigra.

Fig. 7. Smittia/Pseudosmittia type.

Fig. 8. Parakiefferiella triquetra type.

Fig. 9. Paracladius.