title: Climatic effects on mosquito abundance in Mediterranean wetlands.
abstract: BACKGROUND
  The impact of climate change on vector-borne diseases is highly controversial. One of the principal points of debate is whether or not climate influences mosquito abundance, a key factor in disease transmission.
  
  
  METHODS
  To test this hypothesis, we analysed ten years of data (2003-2012) from biweekly surveys to assess inter-annual and seasonal relationships between the abundance of seven mosquito species known to be pathogen vectors (West Nile virus, Usutu virus, dirofilariasis and Plasmodium sp.) and several climatic variables in two wetlands in SW Spain.
  
  
  RESULTS
  Within-season abundance patterns were related to climatic variables (i.e. temperature, rainfall, tide heights, relative humidity and photoperiod) that varied according to the mosquito species in question. Rainfall during winter months was positively related to Culex pipiens and Ochlerotatus detritus annual abundances. Annual maximum temperatures were non-linearly related to annual Cx. pipiens abundance, while annual mean temperatures were positively related to annual Ochlerotatus caspius abundance. Finally, we modelled shifts in mosquito abundances using the A2 and B2 temperature and rainfall climate change scenarios for the period 2011-2100. While Oc. caspius, an important anthropophilic species, may increase in abundance, no changes are expected for Cx. pipiens or the salt-marsh mosquito Oc. detritus.
  
  
  CONCLUSIONS
  Our results highlight that the effects of climate are species-specific, place-specific and non-linear and that linear approaches will therefore overestimate the effect of climate change on mosquito abundances at high temperatures. Climate warming does not necessarily lead to an increase in mosquito abundance in natural Mediterranean wetlands and will affect, above all, species such as Oc. caspius whose numbers are not closely linked to rainfall and are influenced, rather, by local tidal patterns and temperatures. The final impact of changes in vector abundance on disease frequency will depend on the direct and indirect effects of climate and other parameters related to pathogen amplification and spillover on humans and other vertebrates.
authors.forename: David
authors.initials: D
authors.lastname: Roiz
authors.forename: Santiago
authors.initials: S
authors.lastname: Ruiz
authors.forename: Ramón
authors.initials: R
authors.lastname: Soriguer
authors.affiliation: Wetland Ecology Department, Doñana Biological Station, CSIC, Sevilla, Spain. jordi@ebd.csic.es.
authors.forename: Jordi
authors.initials: J
authors.lastname: Figuerola
mesh_terms: D000818:Animals; D002980:Climate; D009033:Culicidae / Q000502:physiology*; D019083:Mediterranean Region; D011156:Population Density; D011891:Rain; D012621:Seasons; D013696:Temperature; D013997:Time Factors; D053833:Wetlands