Dear Kreiling,

I think a comprehensive species key depending on larval characters is yet being constructed. May be some local key are available but not in a large scale. 

-Nilotpol 

Dear Agnes,

Not a taxonomic key, but at least some detailed information about this taxa and its anatomy:

http://chirokey.skullisland.info/genus/Thienemanniella/

Maybe that helps you a bit.

All the best,

Michael

Schmid 1993 mention in his key Thienemanniella acuticornis, clavicornis, partita, majuscula, vittata, sp. D and sp. E

Schmid P.E. 1993. A key to the Chironomidae and their instars from Austrain Dunbe region streams and rivers. Part I, Diamesinae, Prodiamesinae and Orthocladiinae. p. 470-482.