Diet and density dependent competition affect larval performance and oviposition site selection in the mosquito species Aedes albopictus (Diptera: Culicidae)

Yoshioka Miho, Couret Jannelle, Kim Frances, Mcmillan Joseph, Burkot, Dotson, Kitron Uriel, Vazquez-Prokopec

Description

Oviposition-site choice is an essential component of the life history of all mosquito species. According to the oviposition-preference offspring-performance (P-P) hypothesis, if optimizing offspring performance and fitness ensures high overall reproductive fitness for a given species, the female should accurately assess details of the heterogeneous environment and lay her eggs preferentially in sites with conditions more suitable to offspring. Methods We empirically tested the P-P hypothesis using the mosquito species Aedes albopictus by artificially manipulating two habitat conditions: diet (measured as mg of food added to a container) and conspecific density (CD; number of pre-existing larvae of the same species). Immature development (larval mortality, development time to pupation and time to emergence) and fitness (measured as wing length) were monitored from first instar through adult emergence using a factorial experimental design over two ascending gradients of diet (2.0, 3.6, 7.2 and 20 mg food/300 ml water) and CD (0, 20, 40 and 80 larvae/300 ml water). Treatments that exerted the most contrasting values of larval performance were recreated in a second experiment consisting of single-female oviposition site selection assay. Results Development time decreased as food concentration increased, except from 7.2 mg to 20.0 mg (Two-Way CR ANOVA Post-Hoc test, P > 0.1 ). Development time decreased also as conspecific density increased from zero to 80 larvae (Two-Way CR ANOVA Post-Hoc test, P < 0.5 ). Combined, these results support the role of density-dependent competition for resources as a limiting factor for mosquito larval performance. Oviposition assays indicated that female mosquitoes select for larval habitats with conspecifics and that larval density was more important than diet in driving selection for oviposition sites. Conclusions This study supports predictions of the P-P hypothesis and provides a mechanistic understanding of the underlying factors driving mosquito oviposition site selection.

Sujets

• Oviposition
• Diet
• MOSQUITO

Informations

• Publié par: biomed
• Publié le: 01 janvier 2012
• Nombre de lectures: 22
• Langue: English
• Poids de l'ouvrage: 1 Mo

Extrait

Yoshiokaet al. Parasites & Vectors2012,5:225 http://www.parasitesandvectors.com/content/5/1/225

R E S E A R C HOpen Access Diet and density dependent competition affect larval performance and oviposition site selection in the mosquito speciesAedes albopictus (Diptera: Culicidae) 1 11 12,3 2 Miho Yoshioka , Jannelle Couret , Frances Kim , Joseph McMillan , Thomas R Burkot, Ellen M Dotson , 1,4 1,4,5* Uriel Kitronand Gonzalo M VazquezProkopec

Abstract Background:Ovipositionsite choice is an essential component of the life history of all mosquito species. According to the ovipositionpreference offspringperformance (PP) hypothesis, if optimizing offspring performance and fitness ensures high overall reproductive fitness for a given species, the female should accurately assess details of the heterogeneous environment and lay her eggs preferentially in sites with conditions more suitable to offspring. Methods:We empirically tested the PP hypothesis using the mosquito speciesAedes albopictusby artificially manipulating two habitat conditions: diet (measured as mg of food added to a container) and conspecific density (CD; number of preexisting larvae of the same species). Immature development (larval mortality, development time to pupation and time to emergence) and fitness (measured as wing length) were monitored from first instar through adult emergence using a factorial experimental design over two ascending gradients of diet (2.0, 3.6, 7.2 and 20 mg food/300 ml water) and CD (0, 20, 40 and 80 larvae/300 ml water). Treatments that exerted the most contrasting values of larval performance were recreated in a second experiment consisting of singlefemale oviposition site selection assay. Results:Development time decreased as food concentration increased, except from 7.2 mg to 20.0 mg (TwoWay CR ANOVA PostHoc test,P > 0.1). Development time decreased also as conspecific density increased from zero to 80 larvae (TwoWay CR ANOVA PostHoc test,P < 0.5). Combined, these results support the role of densitydependent competition for resources as a limiting factor for mosquito larval performance. Oviposition assays indicated that female mosquitoes select for larval habitats with conspecifics and that larval density was more important than diet in driving selection for oviposition sites. Conclusions:This study supports predictions of the PP hypothesis and provides a mechanistic understanding of the underlying factors driving mosquito oviposition site selection. Keywords:Habitat selection, Oviposition, Diet, Conspecific density, Mosquito

* Correspondence: [e-mail] 1 Emory University, Georgia, Atlanta, USA 4 Fogarty International Center, National Institutes of Health, Bethesda, MD, USA Full list of author information is available at the end of the article

© 2012 Yoshioka et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.