The mosquitoes of Finland: updated distributions and bionomics.

Mosquitoes (Diptera: Culicidae) were collected in Finland between 2012 and 2018 to determine the species present and their distributions. In total, 52 466 specimens from 1031 collections formed the basis for the preparation of distribution maps for each of the 40 species that were collected. Anopheles maculipennis s.s., An. claviger, Aedes geminus and Ochlerotatus sticticus are confirmed on mainland Finland after previous records were uncertain or absent. Coquillettidia richiardii, Culiseta morsitans, Cs. ochroptera, Culex territans, Cx. torrentium, Oc. leucomelas, Oc. nigrinus, Oc. pullatus and Oc. punctodes occur more widely than previously reported. Three species, Ae. rossicus, Cs. subochrea and Oc. cyprius were not collected, although Ae. rossicus was subsequently found in Lapland by another researcher. No invasive species were collected. Ochlerotatus communis, an aggressive biter, was the most commonly encountered species. Larval collection data suggest that several species may have up to three generations per year in Finland, with Cx. torrentium and Cx. pipiens having at least two, and Oc. communis and Oc. punctor regularly found as larvae across the summer. These data, especially when coupled with historical records, are vital for monitoring species which have significant vector potential, particularly when faced with a warming climate.

Molecular detection of Bartonella spp. in deer ked pupae, adult keds and moose blood in Finland.

The deer ked (Lipoptena cervi) is a haematophagous ectoparasite of cervids that harbours haemotrophic Bartonella. A prerequisite for the vector competence of the deer ked is the vertical transmission of the pathogen from the mother to its progeny and transstadial transmission from pupa to winged adult. We screened 1154 pupae and 59 pools of winged adult deer keds from different areas in Finland for Bartonella DNA using PCR. Altogether 13 pupa samples and one winged adult deer ked were positive for the presence of Bartonella DNA. The amplified sequences were closely related to either B. schoenbuchensis or B. bovis. The same lineages were identified in eight blood samples collected from free-ranging moose. This is the first demonstration of Bartonella spp. DNA in a winged adult deer ked and, thus, evidence for potential transstadial transmission of Bartonella spp. in the species.