Key to the known larvae of Zavrelia 1. AAR ≥ 1.2.......................................................................................... 2 - AAR ≤ 1............................................................................................ 3 2. Inner margin of mandible with two spines. First antennal segment 66 μm long. Antennal blade 100 μm long................................................................................................ Z. hudsoni Ekrem & Stur 3. Antennal pedestal ≥ 80 μm long.......................................................................... 4 - Antennal pedestal 70 μm long. Antennal blade <120 μm long; AAR <1.0................................... 6 6. Ventromental plates extend to the third lateral teeth of the mentum. Lauterborn organ 15 μm long (Ekrem & Stur 2009: Figs. 2D–E). The shortest anal setae, close to 120 μm long.................................. Z. pentatoma Kieffer & Bause - Ventromental plates extend to the border of second and third lateral teeth of the mentum. Lauterborn organ 17–26 μm long (Figs.) The shortest anal setae, close to 380 μm long...................................... Z. parapentatoma sp. nov.

Published as part of Namayandeh, Armin, Hudson, Patrick L., Ghaderi, Edris & Stott, Wendylee, 2023, Zavrelia parapentatoma (Chironomidae: Diptera), a curious new species from North America, revealed by molecular methods, pp. 111-124 in Zootaxa 5249 (1) on page 121, DOI: 10.11646/zootaxa.5249.1.6, http://zenodo.org/record/7685359