Mosquito (Diptera: Culicidae) species diversity and abundance patterns across tree height and microclimatic gradients in Indiana, USA

Abstract

Climate, land use and land cover change influence infectious disease dynamics, particularly vector-borne diseases. Knowledge about mosquito ecology in southern Indiana is limited. Here, we present results from a season long study where we sampled mosquitoes at the Hickory Ridge Fire Tower in Hoosier National Forest, Monroe County, Indiana, USA. Using BG-Pro traps with BG-Lure and LED lights weekly from 23 May to 31 October 2023, we collected 178 mosquitoes over 24 weeks of sampling, encompassing a total of 120 trap-nights, with an average of 1.48 ± 3.41 (SD) mosquitoes per trap-night. The species accumulation curve for all the samples was flat, indicating a comprehensive sampling of species. We collected 10 species with a Chao2 ± SE species richness estimate of 14.46 ± 7.14. The dominant species was Aedes vexans (n = 58, 36%), followed by Culex spp. (composed of morphologically indistinguishable Culex pipiens and Culex restuans) (n = 51, 31%), Culex erraticus (n = 16, 10%), and Aedes triseriatus (n = 15, 9%). Because mosquitoes are ectothermic, they are highly sensitive to microclimatic variables such as temperature, humidity, and rainfall. Our time series analysis showed a significant association of mosquito abundance with the variability (SD and kurtosis) of the environmental variables we studied highlighting the importance of weather fluctuations in mosquito ecology. Our study highlights how weather variability shapes mosquito abundance, thus impacting disease vectors like Culex spp. and Aedes triseriatus with implications for arbovirus transmission in the context of climate change.