Chironomus (Chironomus) riparius Meigen

Chironomus riparius Meigen, 1804: 13 . Tendipes thummi Kieffer, 1911: 36 .

Material examined. Lake Winnipeg light traps: 15 km E off Long Point, 1 male, 6.ix 1969; 20 Mile Creek, 1 male, 1.ix. 1971. North Basin: 3 larvae, 4–12.vi. 1969; South Basin, 1 larva, 4–12.vi. 1969.

The two males examined have an AR of 3.00–3.17, 5–9 sensilla chaetica on p2 and 6–11 on p3. The taxonomic status of C. riparius and C. thummi is treated by Credland (1973). A few larvae probably belonging to C. riparius were present in the bottom samples.

Distribution and ecology. The species was previously known from all over the Holarctic region and also is recorded from the Near East and the Neotropical region (Saether & Spies 2011). Townes (1945:125) mentions the species from all over North America, and also gives a record from Argentina. The species is often very common in heavily polluted waters and typically saprophilous (Townes 1945: 126, Thienemann 1954: 646–648, Martin 2012).