Seasonal Differences in Density But Similar Competitive Impact of Aedes albopictus (Skuse) on Aedes aegypti (L.) in Rio de Janeiro, Brazil.
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.
Laboratório de Transmissores de Hematozoários - LATHEMA, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.|Núcleo Operacional Sentinela de Mosquitos Vetores - NOSMOVE, DIRAC - IOC - VPAAPS, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
Daniel Cardoso Portela
DC
Camara
Programa de Computação Científica, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
Claudia Torres
CT
Codeço
School of Biological Sciences, Behavior, Ecology, Evolution and Systematics Section, Illinois State University, Normal Illinois, United States of America.
Steven A
SA
Juliano
Florida Medical Entomology Laboratory, University of Florida, Vero Beach Florida, United States of America.
L Philip
LP
Lounibos
Programa de Computação Científica, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
Thais Irene Souza
TI
Riback
Núcleo Operacional Sentinela de Mosquitos Vetores - NOSMOVE, DIRAC - IOC - VPAAPS, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
Glaucio Rocha
GR
Pereira
Laboratório de Transmissores de Hematozoários - LATHEMA, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.|Núcleo Operacional Sentinela de Mosquitos Vetores - NOSMOVE, DIRAC - IOC - VPAAPS, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
Nildimar Alves
NA
Honorio
D000330:Aedes / Q000254:growth & development / Q000472:pathogenicity / Q000821:virology*; D000818:Animals; D001938:Brazil; D003715:Dengue / Q000453:epidemiology / Q000635:transmission*; D007303:Insect Vectors / Q000472:pathogenicity*; D012621:Seasons; D000071244:Zika Virus / Q000472:pathogenicity; D000071243:Zika Virus Infection / Q000453:epidemiology / Q000635:transmission*