Spatiotemporal organization of cryptic North American Culex species along an urbanization gradient

Arielle Arsenault-Benoit ¹, Megan L Fritz ¹

⁰Department of Entomology, University of Maryland, College Park, MD 20742.

Ecological Solutions and Evidence +

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June 20, 2024

View abstract on PubMed

Summary

Urbanization impacts mosquito vector distribution. Landscape heterogeneity influences Culex pipiens, Culex restuans, and Culex quinquefasciatus abundance, affecting West Nile virus (WNv) transmission risk. Early season control of Culex restuans could reduce WNv burden.

Area Of Science

Environmental Science
Vector Ecology
Public Health Entomology

Background

Landscape heterogeneity and urbanization significantly influence disease vector ecology.
Mosquitoes like Culex pipiens, Culex restuans, and Culex quinquefasciatus are critical vectors of West Nile virus (WNv).
Understanding their distribution and abundance is vital for effective WNv management.

Purpose Of The Study

To investigate how urbanization-driven landscape heterogeneity affects the distribution and relative abundance of three key WNv vectors: Culex pipiens, Culex restuans, and Culex quinquefasciatus.
To identify ecological factors correlating with the spatiotemporal distribution of these mosquito species.
To assess the potential impact of early-season mosquito activity on WNv transmission dynamics.

Main Methods

Mosquitoes were collected from urban, suburban, and rural sites in metropolitan Washington, D.C. from June-October 2019-2021, with extended collection in April-May 2021.
Molecular techniques identified a subset of Culex mosquitoes to species level (n=2,461).
Constrained and unconstrained ordination analyses examined ecological correlates of mosquito distribution and community composition.

Main Results

Culex pipiens was dominant overall, while Culex quinquefasciatus was associated with urban areas and Culex restuans with rural/suburban sites.
Species rarely coexisted, and seasonality influenced community composition, particularly with early-season data.
Site classification, impervious surface, distance to city center, and longitude predicted mosquito community composition.

Conclusions

Human-mediated land-use changes demonstrably influence Culex vector distribution and abundance, even at fine scales.
Culex restuans is active early in the season (April-May), suggesting potential for early WNv transmission.
Targeting early-season Culex restuans and focusing management on suburban areas with mixed Culex assemblages could reduce WNv burden.

Keywords:

Community Assemblage Culex mosquitoes Landscape Heterogeneity Urbanization West Nile virus