Baltimore Ecosystem Study Institute of Ecosystem Studies

2016 BES Annual Meeting Presentation and Poster Abstracts

The effects of UV radiation on tire deterioration and pollutant release on competition between Aedes albopictus and Culex pipiens mosquitoes
Villena, Oswaldo
Co-Authors: Oswaldo C Villena, Paul T Leisnham, Edward Landa, Joe Sullivan.

Abstract: Used vehicle tires degrade when exposed to ultraviolet (UV) radiation and leach numerous soluble contaminants. Studies have shown toxicological effects of tire leachate on a few focal taxa. Although numerous vector mosquito species utilize used tires as developmental sites, there is a lack of knowledge on the effects of tire leachate on mosquito communities. This study investigated the effects of tire contamination on the ecologies of two common tire-utilizing mosquito species, Aedes albopictus and Culex pipiens. The main objectives of this study were to: (1) Examine tire degradation and leachate, using zinc concentrations as a marker contaminant, under different UV radiation treatments; and (2) test the effects of tire leachate on competition between Ae. albopictus and Cx. pipiens. We exposed tires to either full sun, shade, or no UV conditions, and them conducted a competition trial between Ae. albopictus and Cx. pipiens. We sampled zinc concentrations from water, biofilm, and mosquitoes from each treatment. Zinc concentrations were higher from water and biofilm in tires exposed to full sun conditions. Ae. albopictus had higher zinc concentrations than Cx. pipiens. Survival for both species were consistently lower under full sun conditions, and Ae. albopictus regularly had higher survival. These results show that greater UV radiation from full sun conditions advances tire degradation and contaminant leaching, and decreases mosquito survival. Although Ae. albopictus may to be exposed to greater concentrations of contaminants, presumably by browsing leachate-rich biofilm, it was able to maintain competitive dominance over Cx. pipiens indicating the importance of used tires to the spread of this pestiferous invasive species.