Document Type

Article

Publication Title

PLOS ONE

Publication Date

2016

Abstract

Previous studies have shown that the negative effects of density of Ae. albopictus on Ae. aegypti exceed those of Ae. aegypti on Ae. albopictus for population growth, adult size, survivorship, and developmental rate. This competitive superiority has been invoked to explain the displacement of Ae. aegypti by Ae. albopictus in the southeastern USA. In Brazil, these species coexist in many vegetated suburban and rural areas. We investigated a related, but less-well-studied question: do effects of Ae. albopictus on Ae. aegypti larval development and survival occur under field conditions at realistic densities across multiple seasons in Brazil? We conducted additive competition experiments in a vegetated area of Rio de Janeiro where these species coexist. We tested the hypothesis that Ae. aegypti (the focal species, at a fixed density) suffers negative effects on development and survivorship across a gradient of increasing densities of Ae. albopictus (the associate species) in three seasons. The results showed statistically significant effects of both season and larval density on Ae. aegypti survivorship, and significant effects of season on development rate, with no significant season-density interactions. Densities of Aedes larvae in these habitats differed among seasons by a factor of up to 7x. Overall, Spring was the most favorable season for Ae. aegypti survivorship and development. Results showed that under natural conditions the negative competitive effects of Ae. albopictus on Ae. aegypti were expressed primarily as lower survivorship. Coexistence between Ae. aegypti and Ae. albopictus in vegetated areas is likely affected by seasonal environmental differences, such as detrital resource levels or egg desiccation, which can influence competition between these species. Interactions between these Aedes are important in Brazil, where both species are well established and widely distributed and vector dengue, Zika and chikungunya viruses.

Funding Source

This research was funded by US National Institutes of Health Fogarty International Center FIRCA grant R03TW007446-01A1 - received by LPL and SAJ, by INCT-EM/CNPq – PAPES V grant 407744/2012-6, Rede Dengue FIOCRUZ and funds from Instituto Oswaldo Cruz, Brazil, received by NAH. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Comments

First published in PLoS ONE 11(6): e0157120. https://doi.org/10.1371/journal.pone.0157120.

This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.

DOI

10.1371/journal.pone.0157120

Additional Files
climate_data.csv (2 kB)
Climate Data
competition_data.csv (1 kB)
Competition Data
productivity_data.csv (2 kB)
Productivity Data
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