A Scoping Review of Mosquito Vector Range Shifts: Widespread Expansions and Evidence Gaps in Climate Attribution.

Abstract

As global temperatures rise, concerns about shifting mosquito ranges-and accompanying changes in the transmission of malaria, dengue, and other diseases-are mounting. However, systematic evidence for climate-driven changes in mosquito ranges remains limited. We conducted a scoping review following PRISMA-ScR guidelines of studies documenting expansions or contractions in medically important mosquito species. In total, 178 studies on six continents identified range expansions in 118 mosquito species. While over a third of these studies cited warming as a driver, fewer than 10% performed statistical tests of the role of climate. Instead, most expansions were linked to human-aided dispersal (e.g., trade, travel), land-use changes, and urbanization. Although several studies reported poleward or upward expansions consistent with climate warming, none demonstrated warm-edge contractions driven by rising temperatures, which are theoretically predicted in some settings. Rather than expanding into newly suitable areas, many expansions appear to be filling preexisting thermally suitable habitats. Our findings highlight the need for long-term mosquito monitoring, rigorous climate-attribution methods, and better documentation of confounding factors like land-use change and vector control efforts to disentangle climate-driven changes from other anthropogenic factors.