Rheocricotopus (Psilocricotopus) chalybeatus (Edwards, 1929)

Pinho, Luiz Carlos & Andersen, Trond, 2023, The immature stages and female imago of Rheocricotopus (Psilocricotopus) sirventorum Andersen & Mendes, 2012, a Neotropical member of the chalybeatus species group (Diptera, Chironomidae, Orthocladiinae), Zootaxa 5375 (4), pp. 595-600 : 598

Key to the pupae of the Rheocricotopus (Psilocricotopus) chalybeatus group

1 Tergites without median patch of spinules; frontal setae on prefrons or lacking; subgenus Psilocricotopus ................ 2

– Tergites (III)IV– (V)VI each with one median, rounded patch of spines or strong spindles; frontal setae on frontal apotome; subgenus Rheocricotopus (not keyed).

2 Pedes spurii B absent; L setae of segments V–VIII as 3, 3, 3–4, 4–5 or anal lobe with fringe; the chalybeatus group........ 3

– Pedes spurii B present on segment II; L setae of segments V–VIII as 4, 4, 4, 4–5; anal lobe always with fringe (not keyed).

3 Anal lobe without fringe................................................................................ 4

– Anal lobe with fringe.................................................................................. 5

4 L setae on abdominal segments V–VIII as 3, 3, 3, 3, all bristle-like. [ India]...... R. (P.) rarispina Hazra & Chaudhuri, 2004

– L setae on abdominal segments V–VIII as 3–4, 4, 4, 4, all bristle-like except L 1 of VIII. [Europe]................................................................................................... R. (P.) tirolus Lehmann, 1969

5 Second dorsoventral (Dc 2) closer to first (Dc 1) than to third (Dc 3)................................................ 6

– Dc 2 clearly closer to Dc 3 than to Dc 1 ...................................................................... 8

6 Thoracic horn somewhat club-shaped, swollen medially; caudal spines of abdominal tergites III–VII relatively large, clearly contrasting to weak ones on VIII. [ Lebanon]............................... R. (P.) meridionalis Moubayed-Breil, 2016

– Thoracic horn slender, not swollen medially; caudal spines of abdominal tergites III–VII relatively small, not clearly contrasting to those on VIII....................................................................................... 7

7 Abdominal tergite II with 90–100 caudal hooklets. Exuviae greyish brown, comparatively dark. [Oriental China, widespread in Palearctic].............................................................. R. (P.) chalybeatus (Edwards, 1929)

– Abdominal tergite II with 40–59 caudal hooklets. Exuviae hyaline. [ Brazil].... R. (P.) sirventorum Andersen & Mendes, 2012

8 Anal lobe with 26–29 setae in fringe. Thoracic horn slender, 165–259 μm long, sometimes abnormally club-shaped. [Palearctic and Oriental China, Nearctic]................................................ R. (P.) robacki (Beck & Beck, 1964)

– Anal lobe with 10–20 setae in fringe. Thoracic horn club-shaped, 460 μm long. [ India]................................................................................................. R. (P.) valgus Chaudhuri & Sinharay, 1983