Orthocladiinae

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 : 227-229

Orthocladiinae ( Fig. 5 )

Head minute to large, yellow to brown or brown-black, occipital margin can be darkened, dark brown or black. Antenna not longer than head with 4–7 (usually 5) segments (with the exception of Corynoneura , where antennae exceed length of head), third segment never annulate. Labrum and pecten epipharyngis with variable shaped structures (labral setae, labral lamellae) important for identification, however these characteristics usually missing from subfossils. Premandible with 1–6 teeth. Mandible with single apical tooth and usually 3 inner teeth. Mentum is very variable, mostly curved, with 3–29 teeth; mainly 4–6 pairs of lateral teeth are present. Ventromental plates vestigial to relatively large, never with striae; setal beard is present in some genera.

Orthocladiinae head capsules can be separated from Chironominae by absence of striate on ventromental plates, and by the eye-spots (if visible), which often are usually contiguous or, when separate with a dorsal eye-spot posterior to a ventral eye-spot. Diamesinae can be distinguished from orthoclads by having annulate third antennal segment (unfortunately, antenna very often missing) generally higher number of lateral teeth and more robust head occipital margin. The most important characters for subfossil identification are shape, number and arrangement of teeth together with the shape of ventromental plates.

Most of recorded head capsules belong to rheophilic to rheobiontic genera, in less extent to typical lentic and semiterrestrial/ terrestrial genera are present.

Figures

FIGURES 1–8. Diamesinae, Pseudodiamesa nivosa: 1—head capsule. Prodiamesinae, Prodiamesa olivacea: 2—head capsule. Tanypodinae, Procladius: 3—detail of head capsule. Tanypodinae, Zavrelimyia: 4—head capsule. Orthocladiinae, Chaetocladius piger-type: 5—head capsule. Chironominae (Chironomini), Chironomus anthracinus-type: 6—head capsule. Chironominae (Tanytarsini), Micropsectra junci-type: 7—head capsule. Chironominae (Tanytarsini), Micropsectra radialistype: 8—head capsule. li—ligula, pl—paraligula, dt—dorsomental teeth, a—antennae, ma—mandible, om—occipital margin, me—mentum, vp—ventromental plate, b—beard, p—projection on occipital margin, at—apical tooth of the mandible, it—inner teeth of the mandible, ap—antennal pedestal, pm—premandible, s—spur, pp—post-occipital plate, ss—seta submenti