Sex–specific response of a mosquito to parasites and crowding

Tseng, Michelle

doi:10.1098/rsbl.2003.0139

Cited by 30 publications

(24 citation statements)

References 21 publications

(29 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Similar results have been found for different mosquito species infected with microsporidians (Bedhomme et al. 2005) and protozoans (Ferguson & Read 2002; Tseng 2004). In addition, the study by Bedhomme et al.…”

Section: Discussionsupporting

confidence: 87%

The ecology of virulence

Lively¹

2006

Ecology Letters

View full text Add to dashboard Cite

Theoretical work has shown that parasites should evolve intermediate levels of virulence. Less attention has been given to the ecology of virulence. Here I explore population-dynamic models of infection in an annual host. The infection does not kill the host; but it can decrease the number of offspring produced by the host, and the magnitude of this effect depends on host population size. Hence, 'virulence' is density dependent, and is defined here as the difference in birth rates between uninfected and infected hosts, divided by the birth rate of uninfected hosts. The results suggest that infection can be highly virulent at the host's equilibrium density, even though the parasite has no effect on the host's intrinsic birth rate. The results also suggest that parasites may help to stabilize host population dynamics. In general, the impact of infection may be underestimated in natural populations.

show abstract

Section: Discussionsupporting

confidence: 87%

The ecology of virulence

Lively¹

2006

Ecology Letters

View full text Add to dashboard Cite

show abstract

“…Despite the initial 1:1 sex ratio commonly noted for A. albopictus (Gavotte et al, 2009; Lounibos and Escher, 2008; Tseng, 2004), females survived better than males resulting in a female-biased sex ratio (58.3% female) in the low-density treatment (χ 2 = 4.53; Df = 1; p < 0.05). In contrast, proportionally fewer females than expected (42.9%) emerged from the 400 larvae per container treatment (χ 2 = 10.77; Df = 1; p < 0.005).…”

Section: Resultsmentioning

confidence: 84%

Costs and benefits of Wolbachia infection in immature Aedes albopictus depend upon sex and competition level

Gavotte

Mercer

Stoeckle

et al. 2010

Journal of Invertebrate Pathology

View full text Add to dashboard Cite

Bacterial endosymbionts induce various effects on hosts and can dramatically impact host fitness and development. An example is provided by obligate, maternally-inherited Wolbachia, which infect a broad range of invertebrates. Wolbachia are capable of altering host reproduction, thereby promoting infection spread. Wolbachia also pose direct physiological costs and benefits to hosts, complicating their categorization as parasites or mutualists. This study examines for an effect of Wolbachia infection in intraspecific larval competition by Aedes albopictus mosquitoes, with the goal of examining for an impact of Wolbachia infection in mixed populations. Similar to prior work examining for an influence of Wolbachia infection on the fitness of A. albopictus in adults, the results presented here support the hypothesized impact of Wolbachia across all life stages, including immatures. The differential competitiveness of infected larvae detected in our experiments indicates that Wolbachia infected A. albopictus females are less competitive relative to uninfected females when competing under highly competitive conditions. In contrast, under low competitive pressures, infected females experience higher survivorship. Thus, Wolbachia infection shifts from parasitism to mutualism as a function of developmental conditions. Results are discussed in relation to the invasion and persistence of Wolbachia in A. albopictus populations.The results are important to the evolution of stable Wolbachia symbioses, including Wolbachia invasion of an uninfected population. The resulting infection dynamics that occur in an infected population are discussed.

show abstract

“…Additionally, consumption of resources by competing hosts could modify the interaction of hosts with its parasite. Transmission and virulence of parasites can vary sensitively with the quantity and quality of resources consumed by hosts (Jokela et al 1999, Bedhomme et al 2004, Tseng 2004, Fels 2005, Hall et al 2007a, b, Ryder et al 2007; S. R. Hall, J. L. Simonis, R. M. Nisbet, A. J. Tessier, and C. E. Ca´ceres, unpublished manuscript). Since competition and epidemiology may hinge centrally on these resources, the net outcome of competition and dilution could influence disease dynamics in manners that defy a priori prediction.…”

Section: Introductionmentioning

confidence: 99%

Friendly competition: evidence for a dilution effect among competitors in a planktonic host–parasite system

Hall

Becker

Simonis

et al. 2009

Ecology

107

101

View full text Add to dashboard Cite

The "dilution effect" concept in disease ecology offers the intriguing possibility that clever manipulation of less competent hosts could reduce disease prevalence in populations of more competent hosts. The basic concept is straightforward: host species vary in suitability (competence) for parasites, and disease transmission decreases when there are more incompetent hosts interacting with vectors or removing free-living stages of a parasite. However, host species also often interact with each other in other ecological ways, e.g., as competitors for resources. The net result of these simultaneous, multiple interactions (disease dilution and resource competition) is challenging to predict. Nonetheless, we see the signature of both roles operating concurrently in a planktonic host-parasite system. We document pronounced spatiotemporal variation in the size of epidemics of a virulent fungus (Metschnikowia bicuspidata) in Midwestern U.S. lake populations of a dominant crustacean grazer (Daphnia dentifera). We show that some of this variation is captured by changes in structure of Daphnia assemblages. Lake-years with smaller epidemics were characterized by assemblages dominated by less suitable hosts ("diluters," D. pulicaria and D. retrocurva, whose suitabilties were determined in lab experiments and field surveys) at the start of epidemics. Furthermore, within a season, less suitable hosts increased as epidemics declined. These observations are consistent with a dilution effect. However, more detailed time series analysis (using multivariate autoregressive models) of three intensively sampled epidemics show the signature of a likely interaction between dilution and resource competition between these Daphnia species. The net outcome of this interaction likely promoted termination of these fungal outbreaks. Should this outcome always arise in "friendly competition" systems where diluting hosts compete with more competent hosts? The answers to this question lie at a frontier of disease ecology.

show abstract

Sex–specific response of a mosquito to parasites and crowding

Cited by 30 publications

References 21 publications

The ecology of virulence

The ecology of virulence

Costs and benefits of Wolbachia infection in immature Aedes albopictus depend upon sex and competition level

Friendly competition: evidence for a dilution effect among competitors in a planktonic host–parasite system

Contact Info

Product

Resources

About