Rheosmittia spinicornis (Brundin, 1956)

Namayandeh, Armin & Beresford, David V., 2017, New range extensions for the Canadian Chironomidae fauna from two urban streams, CHIRONOMUS Journal of Chironomidae Research 30 (30), pp. 76-80 : 77-78

Rheosmittia spinicornis (Brundin, 1956)

Pharate male (n=3). Fig. 2 a-b.

Diagnosis. Antenna with 11 flagellomeres, AR=0.47. Thorax with prominent scutal tubercle ( Fig. 2a ). Inferior volsella digitiform and directed posteriorly ( Fig. 2b ).

Pupa (n=3). Fig. 2c, d .

Description. Exuviae hyaline ( Fig. 2c ). Frontal setae absent. Precorneal seta 1-3 Ls =43.3, 51.0, 33.1 μm long. Dorsocentral setae about 38.8-47.8 μm long. Anal lobe and genital sac ( Fig. 2d ).

Notes. A detailed description of species is given by Cranston and Saether (1986).

Study sites. Bowmanville Creek, Bowmanville , Ontario; 43° 54’ 22.90” N 78° 41’ 12.8” W. Lynde Creek, Whitby , Ontario; 43° 54’ 42.27” N 78° 57’ 52.4” W.

Ecology and habitats. Larvae of Rheosmittia are psammophile ( Cranston and Saether 1986).

Nearctic distribution: Canada (British Colombia, Northwest Territories, 1 st record Ontario, Saskatchewan, Yukon Territory).

Notes. Originally, this s pecies was reported only from the Palearctic region ( Ashe and O’Connor 2012); however, according to entries in the Barcode of Life Data Systems ( Ratnasingham and Hebert 2007), this species also occurs in British Columbia, Northwest Territories, Saskatchewan and Yukon Territory. Considering our new record in Ontario, this species is probably widespread across the northern, western and central region of Canada.

Figures

Figure 2. Rheosmittia spinicornis (Brundin, 1956) pharate male a-b, pupa c-d. a) Thorax, arrow indicates the location of scutal tubercle, b) Hypopygium, arrows indicate the inferior volsella, c) Cephalothorax, d) Anal lobes and genital sacs.