WolbachiaInfection and Resource Competition Effects on ImmatureAedes albopictus(Diptera: Culicidae)

Abstract

Wolbachia pipientis Hertig and Wolbach (Rickettsiales: Rickettsiaceae) are intracellular α-proteobacteria that occur naturally in Aedes albopictus (Skuse) (Diptera: Culicidae) and numerous other invertebrates. These endosymbionts can invade host populations by manipulating host reproduction. Wolbachia infections have been shown to impart both costs and benefits to hosts in terms of development, survival, and fecundity. Here, we monitor intraspecific competition among independent cohorts of infected or uninfected larvae. Levels of competition are manipulated by varying initial larval densities and food levels. Although larval density is observed to have major impacts on immature survivorship, sex ratio of eclosing adults, and developmental rates, the Wolbachia infection status had minimal impact on male immatures and no effect on immature females under these experimental conditions. Female and male immatures were observed to respond differently to competitive pressure, with the functional relationships of females and males consistent with scramble and contest competition, respectively. The results are discussed in relation to the evolution of naturally occurring Wolbachia infections in Ae. albopictus (i.e., natural population replacement events) and public health strategies that propose the manipulation of Wolbachia infections in Ae. albopictus populations.

Larval Competition Extends Developmental Time and Decreases Adult Size of wMelPop Wolbachia-Infected Aedes aegypti

“…19,33 Sex-specific effects are expected in maternally transmitted endosymbionts because selection pressures acting on males are different than those acting on females. We found no clear sex-specific effects of either Wolbachia infection in our experiments.…”

“…albopictus suggest that Wolbachia infection reduces fitness under high stress conditions. 33 A minor cost to survival of Wolbachia-infected larvae relative to uninfected larvae could render invasion difficult. 31 Therefore, it is important to assess the effect of wMelPop infection on competition for resources with uninfected larvae under stress.…”

Effect of food types on competitive interaction between Aedes aegypti (LINNAEUS, 1762) and Ae. albopictus (SKUSE, 1894) (Diptera, Culicidae): a proximate level appraisal

“…In addition to numerical abundance, environmental factors like temperature (LOUNIBOS et al 2002, KIRBY & LINDSAY 2009, WESTBROOK et al 2010, COURET et al 2014, EWING et al 2016) and food resources (RENSHAW et al 1994, ARRIVILLAGA & BARRERA 2004 influence the outcome of larval development. The outcome of both interspecific and intraspecific competition influences the population dynamics of both these mosquito species, as is evident from different laboratory and field studies (AGNEW et al 2002, GAVOTTE et al 2009, GILLES et al 2011. Competitive effects can be evaluated through variations in life history traits like pupal weight, adult weight and wing length (AGNEW et al 2002, JULIANO 2009.…”

Alterações reprodutivas causadas pela infecção por Wolbachia pipientis em Culex quinquefasciatus.

“…Como Wolbachia tem sido apontada como possível instrumento de controle populacional de insetos Laven, 1967a) e controle de transmissão de patógenos vetoriadas por mosquitos, (Blagrove et al, 2012;IturbeOrmaetxe et al, 2011;Maciel-de-Freitas et al, 2012;van den Hurk et al, 2012;Werren, 1997) (Dong et al, 2007;Fry et al, 2004) ou desvantagens (Fleury et al, 2000;Fry et al, 2004) para os indivíduos infectados e é sabido que estas alterações dependem da cepa da bactéria e de seu hospedeiro Duron et al, 2006 (Gavotte et al, 2009). …”

“…A nossa comparação do tempo de desenvolvimento larval (mais rápido em mosquitos wPip -; Tabela 1) é um fator que pode alterar a dinâmica populacional (Gavotte et al, 2009;Islam, Dobson, 2006 (Clements, 1992;Araujo et al, 2011).…”