26. Culex (Culex) pipiens Linnaeus, 1758

(Fig. 4H)

Published sources: Remm (1957: 157), Burtin (2014: 39), Kirik et al. (2021: 11, as Cx. (Cux.) pipiens / torrentium).

Voucher material: 1♀, Tartu (58° 21′ 23″ N, 26° 44′ 31″ E), 24.IX.2017, T. Kesküla leg., H. Kirik det., sweep net, IZBE0210226, GenBank: OK465176; 1♂, Tartu (58° 23′ 05″ N, 26° 42′ 19″ E), 27.IX.2016, H. Kirik leg., H. Kirik det., sweep net, IZBE0210248; 1♀, Tartu (58° 21′ 26″ N, 26° 42′ 60″ E), 28.VIII.2017, T. Kesküla leg., H. Kirik det., sweep net, IZBE0210227, GenBank: OK465177 .

Comment: Adults of Cx. pipiens are difficult to distinguish from Cx. torrentium by morphological characteristics alone. However, when 12 Cx. pipiens / torrentium females were subjected to DNA barcoding, five (41.7%) were identified as Cx. pipiens . In 2013, 64 (48.5%) male mosquitoes were identified as Cx. pipiens compared to 68 (51.5%) determined to be Cx. torrentium . In 2017. however, 84 (60.9%) males were identified as Cx. pipiens and only 54 (39.1%) were identified as Cx. torrentium . Based on this information, Cx. pipiens and Cx. torrentium could be present in relatively similar numbers in Estonia. It is possible that the true relative abundance of Cx. pipiens is underestimated in this study due to collection bias. Mosquitoes identified as Cx. pipiens / torrentium were most numerous in September. Also, Cx. pipiens specimens in Estonia were found to be infected with the intercellular symbiont Wolbachia pipientis, which agrees with the published literature (Bergman & Hesson 2021; Inácio da Silva et al. 2021). No attempts were made to identify the “molestus” biotype of Cx. pipiens among the specimens collected during the study.