Background <p>Arthropod-borne viruses are increasingly reported across Europe, with <i>Culex pipiens</i> serving as the main vector of West Nile and Usutu viruses. The <i>C. pipiens</i> complex comprises two ecologically distinct ecotypes, <i>pipiens</i> and <i>molestus</i>, which can hybridise. These ecotypes are thought to differ in habitat preference, with <i>C. p. molestus</i> more frequent in urban environments and <i>C. p. pipiens</i> in natural ones. However, many studies have either not distinguished between these ecotypes or have investigated them without considering a clear landscape gradient. This information is nevertheless important for understanding vector distribution and the potential implications for virus transmission pathways and spillover risk.</p> Methods <p>A season-long survey was conducted from May to September 2025 across 57 sampling sites in Switzerland. Mosquitoes were morphologically identified, and <i>C. pipiens</i> ecotypes were distinguished using molecular analyses. We characterised landscape composition and their scale of effects, as well as meteorological conditions on the sampling dates to determine their influence on the presence and relative proportion of each <i>C. pipiens</i> ecotype.</p> Results <p>Agricultural landscapes promoted all ecotypes, urbanisation positively influenced <i>C. p. pipiens</i> but not <i>C. p. molestus</i>, and forest cover reduced the presence and relative proportion of hybrids. In addition, temperature was positively correlated with all ecotype presence, whereas rainfall had no detectable effect.</p> Conclusions <p>The responses to landscape variables differ among <i>C. pipiens</i> ecotypes and across different landscape features. This highlights the complex, context-dependent interactions between the ecology of mosquitoes and the composition of their habitat, which ultimately determine their spatial distribution patterns.</p> Graphical Abstract <p></p>