Chaetocladius Kieffer, 1911

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 : 230

Chaetocladius Kieffer ( Figs 29–31 )

Head yellow to light brown with darkened occipital margin. Antenna 5 segmented, never strongly reduced ( Fig. 29A ). Premandible bifid with 1–2 blunt inner teeth ( Fig. 29 ). Labral lamellae of various shape usually well developed between labral setae SI, but can be vestigial or absent ( Fig. 30 ). Apical mandibular tooth shorter than combined width of 3 inner teeth. Mentum with 1–2 median teeth and 5 pairs of lateral teeth, the outermost tooth may be reduced. Ventromental plates usually large, rounded and extending beyond outer lateral mental tooth.

Remarks: The shape of mentum is often the only character that can be used for the identification of subfossils. Parametriocnemus , Paraphaenocladius , Heterotrissocladius have mentum with double median tooth, and 5 pairs of laterals, combined with large ventromental plates extending beyond the outer lateral teeth without beard. Setae submenti of Chaetocladius are arising under the ventromental plates ( Fig. 31 ) while there are located much higher in Parametriocnemus and Paraphaenocladius (see Fig. 58 ). The outermost mental tooth is not reduced in Heterotrissocladius . Metriocnemus, Hydrobeanus and Thienemannia have similar menta, however without large ventromental plates and obviously narrower median teeth/ tooth.

The only Chaetocladius identified to species level from the Tatra Mts. is C. bitusiki Moubayed, 2019 (Moubayed & Bitusik 2019).

The morphotype recognized in our material corresponds to Brooks et al. (2007).

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).

FIGURES 54–59. Metriocnemus fuscipes-type: 54—head capsule. Orthocladius (Orthocladius) dentifer-type: 55—head capsule. Orthocladius (Mesorthocladius) frigidus: 56—head capsule (arrow indicates seta submenti). Orthocladius (Euorthocladius): 57—head capsule. Parametriocnemus/Paraphaenocladius: 58 (arrow indicates seta submenti). Parorthocladius: 59—head capsule.