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 I. In: I. R. Walker (Ed.), The WWW Field Guide to Subfossil Midges. (http://www.sci.ouc.bc.ca/fwsc/iwalker/chironomid/orthocladiinae/orthkey.htm)

Last Update: 11 June 1997

©1997 Ian R. Walker. ALL RIGHTS RESERVED

1. • a) Head capsule with numerous long setae (position of setae may be apparent only by the sockets from which they originate when the setae have been lost from fossils); mentum weakly convex with 2 distinct pairs of lateral teeth (Fig. 1)
     .............................................................................Protanypus
     
     
   • b) Head capsule with normal number of setae; if mentum weakly convex, then mentum has 4 or more pairs of distinct lateral teeth (Fig. 2, 5)
     .............................................................................2.
   
   
   
   
2. • a) Setae submenti set far back on head capsule (distance of setae from posterior head capsule margin less than, or equal to, distance from setae to mentum) (Fig. 3)
     .............................................................................3.
     
     
   • b) Setae submenti closer to mentum than posterior margin of head capsule (Fig. 5)
     .............................................................................4.
   
   
   
   
3. • a) Ventromental plates wholly or partially concealing lateral teeth of the mentum; mentum with one broad median tooth (Fig. 2).
     .............................................................................Pagastia
     
     
   • b) Ventromental plates not overlapping or concealing any mental teeth; mentum with even number of teeth, or if mentum has odd number of teeth, then median tooth very small and narrow (Fig. 3).
     .............................................................................Brillia/Euryhapsis
   
   
   
   
4. • a) Mentum with 4 or more pairs of lateral teeth (Fig. 5)
     .............................................................................Part II.
     
     
   • b) Mentum with 2 pairs of lateral teeth (Fig. 4).
     .............................................................................Orthocladius (Symposiocladius) lignicola
   
   
   
   

Fig. 1. Protanypus.

Fig. 2. Pagastia

Fig. 3. Brillia/Euryhapsis.

Fig. 4. Orthocladius (Sympoiocladius) lignicola.

Fig. 5. Heterotanytarsus.