Brillia Kieffer, 1913

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 : 229-230

Brillia Kieffer ( Fig. 28 )

Head capsule triangular and yellow. Antenna with 4 segments, second segment divided into small proximal and longer (~ 3x) distal part ( Fig. 28A ). Premandible bifid, weak notch between teeth. Mandible with 4 inner teeth. Mentum dark brown with two long median teeth, a very small tooth usually present in between bases of them, and 5 pairs of lateral teeth. Ventromental plates small, triangular. Setae submenti positioned on the submentum closer to occipital margin than base of mentum ( Fig. 28 ).

Remarks: Larval Brillia is similar to Euryhapsis and Eurycnemus and can be differentiated by details on antennae and labrum, even though these structures are usually absent in subfossil material. However, neither of these genera have been recorded in Slovakia and their occurrence in the Tatra Mts. is unlikely.

Two subfossil morphotypes of Brillia can be distinguished corresponding to modesta and flavifrons species groups following Oliver & Roussel (1983). As the valid name of B. modesta is B. bifida (see Moller Pillot 2013), the morphotype is named B. bifida- type.

Only one morphotype was found in the studied lakes.

Figures

FIGURES 28–31. Brillia bifida-type: 28—head capsule (arrows indicate fourth and fifth lateral teeth of the mentum and position of seta submenti), A—antenna (arrow indicates second segment). Chaetocladius piger-type: 29—bifid premandible, A—antenna. C. piger-type: 30—labral lamellae (arrow indicates its position). C. piger-type: 31—head capsule (arrow indicates seta submenti), A—detail of mentum (arrows indicate minute last lateral tooth and bulbous ventromental plate).