Parametriocnemus Goetghebuer, 1931

Namayandeh, Armin & Beresford, David V., 2018, A NEW SPECIES IN THE RHEOCRICOTOPUS (R.) EFFUSUS GROUP FROM CANADA WITH A REVIEW OF THE NEARCTIC SPECIES OF RHEOCRICOTOPUS AND PARAMETRIOCNEMUS (CHIRONOMIDAE: ORTHOCLADIINAE) Abstract, CHIRONOMUS Journal of Chironomidae Research 31, pp. 16-29 : 20-22

Key to the known Nearctic adult male Parametriocnemus Goetghebuer

Abbreviations: AnP = Anal Point; CD = Crista Dorsalis; Gc = Gonocoxite; Gs = Gonostyle; IVo = Inferior Volsella; SVo = Superior Volsella; T = Tergite.

1a. TIX with AnP short not reaching the IVo ( Saether 1969, fig.62)... P. gramnicola (Lundbeck)

1b. TIX with AnP longer, reaching the IVo........... 2

2a. IVo narrow, finger-like with hooked apex ( Fig. 1e ; Sublette 1967, fig. 35)........................................ ........................................ P. hamatus (Johannsen)

2b. IVo with broad base and rounded apex............ 3

3a. AnP very long reaching beyond IVo; CD enlarged, broadly projecting above the inner margin of Gs ( Saether 1969, fig. 65)..................................... ............................................. P. vespertinus Saether

3b. AnP short, reaching only as far as IVo; CD either inconspicuous or present as small preapical to oth......................................................................... 4

4a. IVo with a broad basal attachment about half the length of Gc. AnP with weak lateral setae ( Saether 1969, fig. 63; Sublette 1967, fig. 33)...... .................................... P. lundbeckii (Johannsen) *

4b. IVo with narrow basal attachment about quarter length of Gc. AnP with bristle-like setae.......... 5

5a. Gs angular distally with dorsal ridge ending in small sharply pointed CD ( Saether 1969, fig. 58)... .................................................. P. eoclivus Saether

5b. Gs somewhat rounded distally with weak dorsal margin merging with poorly defined CD (Gowin and Thienemann 1942, fig. 2).............................. ............. P. boreoalpinus Gowin and Thienemann

*Will also key to Parametriocnemus stylatus (Spärck, 1923) , a Palearctic species. Parametriocnemus lundbeckii and P. stylatus closely resemble each other. The two species can partially be separated based on the characters of gonostyle. The gonostyle of P. stylatus is much narrower and tubeshape. It also lacks the prominent crista dorsalis present in most variations of P. lundbeckii . Saether (1969) suggested that the synonymy of both species cannot be excluded. However, the two species can be separated based on partial COI DNA sequences (DNA barcodes).

Figures

Figure 1. Parametriocnemus hamatus (Johannsen) male. a) antenna, b) head, c) thorax lateral view, d) wing, e) hypopygium.