Characterisation of riverine mosquito (Diptera: Culicidae) community structure in southern Australia and the impact of a major flood based on analysis of a 20-year dataset.

We investigated the mosquito community along 315 km of the Murray River, where we identified three assemblages (upper, middle, and lower river) that exhibited different patterns of species richness and diversity over 20 years. In the lower reaches (i.e., more southern latitudes), species richness and community diversity declined over time, while there was no significant change in either the middle or upper reaches. While the overall mean abundance of the common, pathogen-carrying mosquito (Diptera: Culicidae) species Aedes camptorhynchus Thomson, increased in the lower river but declined in the upper river. These results provide important information on the diversity and abundance of mosquito communities adjacent to the Murray River and highlight the importance of considering spatial and temporal variation when assessing the risk of mosquito-borne diseases. Furthermore, data presented here illustrate that there the common public narrative around increasing mosquito abundance and geographic expansion under climate change is not universally true.