Eutrophication and predator presence overrule the effects of temperature on mosquito survival and development

• Published in: PLoS neglected tropical diseases Vol. 12; no. 3; p. e0006354
• Main Authors: Schrama, Maarten, Gorsich, Erin E., Hunting, Ellard R., Barmentlo, S. Henrik, Beechler, Brianna, van Bodegom, Peter M.
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 26.03.2018; Public Library of Science (PLoS)
• Subjects: Analysis; Anopheles gambiae; Aquatic insects; Biodiversity; Biology and Life Sciences; Chironomidae; Chironomus riparius; Climate change; Conspecifics; Culicidae; Diptera; Dynamics; Ecological effects; Ecological monitoring; Ecology and Environmental Sciences; Ecosystems; Emergence; Environmental science; Eutrophication; Experiments; Funding; Health risks; Human influences; Interactions; Interspecific relationships; Life history; Malaria; Medical research; Medicine and Health Sciences; Mesocosms; Mineral nutrients; Mosquitoes; Nutrient availability; Nutrients; Parameters; Physical Sciences; Population studies; Populations; Precipitation; Predation; Predators; Predictions; Research and Analysis Methods; Risk factors; Site selection; Studies; Survival; Temperature; Temperature effects; Temperature requirements; Tropical diseases; Vector-borne diseases; Veterinary colleges; Veterinary medicine; Viruses; West Nile virus; Oregon; Netherlands; United States > US; Colorado
• ISSN: 1935-2735; 1935-2727; 1935-2735
• DOI: 10.1371/journal.pntd.0006354

Adequate predictions of mosquito-borne disease risk require an understanding of the relevant drivers governing mosquito populations. Since previous studies have focused mainly on the role of temperature, here we assessed the effects of other important ecological variables (predation, nutrient availability, presence of conspecifics) in conjunction with the role of temperature on mosquito life history parameters. We carried out two mesocosm experiments with the common brown house mosquito, Culex pipiens, a confirmed vector for West Nile Virus, Usutu and Sindbis, and a controphic species; the harlequin fly, Chironomus riparius. The first experiment quantified interactions between predation by Notonecta glauca L. (Hemiptera: Notonectidae) and temperature on adult emergence. The second experiment quantified interactions between nutrient additions and temperature on larval mortality and adult emergence. Results indicate that 1) irrespective of temperature, predator presence decreased mosquito larval survival and adult emergence by 20-50%, 2) nutrient additions led to a 3-4-fold increase in mosquito adult emergence and a 2-day decrease in development time across all temperature treatments, 3) neither predation, nutrient additions nor temperature had strong effects on the emergence and development rate of controphic Ch. riparius. Our study suggests that, in addition to of effects of temperature, ecological bottom-up (eutrophication) and top-down (predation) drivers can have strong effects on mosquito life history parameters. Current approaches to predicting mosquito-borne disease risk rely on large-scale proxies of mosquito population dynamics, such as temperature, vegetation characteristics and precipitation. Local scale management actions, however, will require understanding of the relevant top-down and bottom-up drivers of mosquito populations.