The role of tire leachate in condition-specific competition and the persistence of a resident mosquito from a competitively superior invader

Authors: VILLENA, OSWALDO - University Of Maryland; SULLIVAN, JOSEPH - University Of Maryland; LANDA, EDWARD - University Of Maryland; YARWOOD, STEPHANIE - University Of Maryland; TORRENS, ALBA - University Of Maryland; Zhang, Aijun; LEISNHAM, PAUL - University Of Maryland

Submitted to: Insects
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/18/2022
Publication Date: 10/22/2022
Citation: Villena, O.C., Sullivan, J.H., Landa, E.R., Yarwood, S.A., Torrens, A., Zhang, A., Leisnham, P.T. 2022. The role of tire leachate in condition-specific competition and the persistence of a resident mosquito from a competitively superior invader. Insects. https://doi.org/10.3390/insects13080663.
DOI: https://doi.org/10.3390/insects13080663

Interpretive Summary: The invasive mosquito, Aedes albopictus, is known as the Asian tiger mosquito and is currently the most invasive mosquito in the world. It comes from the tropical and subtropical areas of Southeast Asia. It is of medical importance due to its aggressive daytime human-biting behavior and ability to vector many viruses, including dengue fever, yellow fever, Zika, West Nile. The native mosquito, Culex pipiens, also called common house mosquito, is the least dangerous mosquito. They prefer to bite birds rather than humans because human blood is not a preferred meal for this insect. Many studies have shown that the resident common house mosquito persists with the competitively superior invasive Asian tiger mosquito in urban areas of the United States. Discarded vehicle tires in urban areas degrade to leach contaminants into collected rainwater that provide habitats for these mosquitoes. In this study, we found stronger competitive effects of common house mosquito on the population performance and survival of Asian tiger mosquito in tires exposed to shade and full-sun conditions that had higher concentrations of tire leachate than the tires stored in the places with the conditions of no UV light from the sunshine. This suggested that increased tire degradation promotes condition-specific competition and facilitates the regional persistence of common house mosquito after the invasion of Asian tiger mosquito. This information will be useful for health professionals and public mosquito control agencies to advise or direct commercial establishments which store a large number of tires exposed to sunny conditions that accelerate tire rubber degradation, facilitating competition of the common house mosquito over the Asian tiger mosquito, contributing to protecting human health and reducing mosquito annoyance.

Technical Abstract: (1) Background: Condition-specific competition, when the outcome of competition varies with abiotic conditions, can facilitate species coexistence in spatially or temporally variable environments. Discarded vehicle tires degrade to leach contaminants into collected rainwater that provide habitats for competing mosquito species. We tested the hypothesis that more highly degraded tires that contain greater tire leachate alters interspecific mosquito competition to produce a condition-specific advantage for the resident, Culex pipiens, by altering the effects of competition with the competitively superior invasive Aedes albopictus. (2) Methods: In a competition trial, varying densities of newly hatched Ae. albopictus and Cx. pipiens larvae were added to tires that had been exposed to three different ultraviolet (UV)-B conditions that mimicked full-sun, shade, or no UV-B conditions in the field. We also measured Cx. pipiens and Ae. albopictus oviposition preference among four treatments with varying tire leachate (high and low) and resources (high and low) amounts to determine if adult gravid females avoided habitats with higher tire leachate. (3) Results: We found stronger competitive effects of Cx. pipiens on the population performance and survival of Ae. albopictus in tires exposed to shade and full-sun conditions that had higher concentrations of contaminants. Further, zinc concentration was higher in emergent adults of Ae. albopictus than Cx. pipiens. Oviposition by these species was similar between tire leachate treatments but not by resource amount. (4) Conclusions: These results suggest that degraded tires with higher tire leachate may promote condition-specific competition by reducing the competitive advantage of invasive Ae. albopictus over resident Cx. pipiens and, combined with Cx. pipiens’ preferential oviposition in higher resource sites, contribute to the persistence of the resident species.