Tvetenia Kieffer, 1922

Chamutiová, Tímea, Hamerlík, Ladislav & Bitušík, Peter, 2020, Subfossil chironomids (Diptera, Chironomidae) of lakes in the Tatra Mountains an illustrated guide, Zootaxa 4819 (2), pp. 216-264 : 244-246

Tvetenia Kieffer ( Fig. 69 )

Head capsule yellow to light-brown, occipital margin pale or dark brown. Antenna 5-segmented, premandible with one apical blunt tooth. Apical tooth of mandible shorter than combined width of 3 inner teeth, mola usually with 2–3 spines, some species without spines. Mentum striped, with 1 or 2 median teeth and 5 pairs of lateral teeth. Ventromental plates narrow creating an appearance of dark bulge below last lateral tooth of mentum. Setae submenti arising either well below mentum (in T. bavarica group) or just below bases of mentum ( T. discoloripes group).

Remarks: Tvetenia closely resembles Eukiefferiella , however, some Eukiefferiella types /species can be easily distinguished from Tvetenia if they posses one of the following features: dark, heavily pigmented head (yellow in Tvetenia ), very broad median mental tooth (e.i. ca 4x width of first lateral tooth, which is always less in Tvetenia ), 4 lateral teeth (always 5 in Tvetenia ). Tvetenia bavarica - type can be distinguished by the position of seta submenti, arising well below mentum while being close to the bases in Eukiefferiella . Species with similar coloration of head, number of lateral teeth and position of seta submenti cannot be distinguished with certainty in subfossils.

Tvetenia bavarica (Goetghebuer, 1934) is the only species recorded from the Tatra Mts. lakes ( Bitušík et al. 2006a; Novikmec et al. 2015).

Subfossil remains were rarely found in small number of investigated lakes. One morphotype was identified following Brooks et al. (2007).

Figures

FIGURES 66–71. Synorthocladius: 66—head capsule, A—detail of mentum. Synorthocladius: 67—mandible (arrow indicates spine). Thienemanniella clavicornis-type: 68—head capsule. Tvetenia bavarica-type: 69—head capsule (arrow indicates seta submenti). Zalutschia mucronata-type: 70—head capsule, A—antenna, blade longer than flagellum. Zalutschia type B: 71—head capsule.