Key to Genera in the Tribe Chironomini

Ian R. Walker & K. Brodersen

Recommended Citation:
Walker, I. R., and K. Brodersen, 1997. Key to genera in the tribe Chironomini. Part V. In: I. R. Walker (Ed.), The WWW Field Guide to Fossil Midges. (http://www.paleolab.ca/wwwguide/chironomini/odd.htm)

Last Update: 1 June 1997

©2007 Ian R. Walker. ALL RIGHTS RESERVED

1. • a) Median tooth pale, lateral teeth dark or light; ventromental plates projecting forward in median area, having origin associated with median tooth (Fig. 1, 2)
     .............................................................................2.
     
     
   • b) All teeth dark, similarly pigmented; median origin of ventromental plates not associated with median tooth (Fig. 3)
     .............................................................................3.
   
   
   
   
2. • a) Median tooth very broad, constituting about 1/3 of the mental width; mandible not sickle-shaped; 3 inner mandibular teeth (Fig. 1)
     .............................................................................Paralauterborniella
     
     
   • b) Median tooth not exceptionally broad, composing about 1/5 of the mental width; mandible sickle-shaped; 4 inner mandibular teeth (Fig. 2)
     .............................................................................Nilothauma
   
   
   
   
3. • a) Median tooth distinctly trifid (except when very strongly worn), and flanked by 6 lateral pairs (thus giving the appearance of 15 teeth total); anterior ventromental margin smooth; striae discernible in posterior field only (Fig. 3).
     .............................................................................Chironomus
     
     
   • b) Median tooth often notched laterally, but not distinctly trifid, and flanked by 6 lateral pairs (thus giving the appearance of 13 teeth total); ventromental plates distinctly striated, with most specimens having finely crenate anterior margins (Fig. 4, 5).
     .............................................................................4.
   
   
   
   
4. • a) Width of each ventromental plate about as wide, or wider than mentum; mental teeth low, rounded (Fig. 4)
     .............................................................................Glyptotendipes & SOME ENDOCHIRONOMUS???!!!
     
     
   • b) Width of each ventromental plate about 3/4 of mental width; mental teeth long, separated by deep notches (Fig. 5).
     .............................................................................Dicrotendipes
   
   
   
   

Fig. 1. Paralauterborniella.

Fig. 2. Nilothauma.

Fig. 3. Chironomus

Fig. 4. Glyptotendipes.

Fig. 5. Dicrotendipes.