British container breeding mosquitoes: the impact of urbanisation and climate change on community composition and phenology

The proliferation of artificial container habitats in urban areas has benefitted urban adaptable mosquito species globally. In areas where mosquitoes transmit viruses and parasites, it can promote vector population productivity and fuel mosquito-borne disease outbreaks. In Britain, storage of water in garden water butts is increasing, potentially expanding mosquito larval habitats and influencing population dynamics and mosquito-human contact. Here we show that the community composition, abundance and phenology of mosquitoes breeding in experimental water butt containers were influenced by urbanisation. Mosquitoes in urban containers were less species-rich but present in significantly higher densities (100.4±21.3) per container than those in rural containers (77.7±15.1). Urban containers were dominated by Culex pipiens (a potential vector of West Nile Virus [WNV]) and appear to be increasingly exploited by Anopheles plumbeus (a human-biting potential WNV and malaria vector). Culex phenology was influenced by urban land use type, with peaks in larval abundances occurring earlier in urban than rural containers. Among other factors, this was associated with an urban heat island effect which raised urban air and water temperatures by 0.9°C and 1.2°C respectively. Further increases in domestic water storage, particularly in urban areas, in combination with climate changes will likely alter mosquito population dynamics in the UK

Mean total mosquito densities per container (±se) of each development stage of subfamilies Anophelinae and Culicinae by location and year.

<p>Results from best fit generalised linear mixed model fit by Laplace approximation. There was no significant main or interaction effect of ‘location’, ‘year’, or ‘season’ on <i>Anopheles</i> (analyses not shown). Bold type denotes significance at the 5% level.</p

Total (%) of mosquito species collected (as pupae) from rural and urban containers in 2011and 2012 and their potential as vectors of disease.

<p>*Information of host preference taken from Medlock et al. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0095325#pone.0095325-Medlock2" target="_blank">[32]</a> and disease vector status from Medlock et al. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0095325#pone.0095325-Medlock1" target="_blank">[31]</a> and ¹Schaffner et al. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0095325#pone.0095325-Schaffner1" target="_blank">[28]</a>.</p

Total number and composition of mosquito species collected from containers.

<p>Individuals collected as pupae in 2011 from rural (a) and urban (b) containers and in 2012 from rural (c) and urban containers (d), April to October. Note the Y axis is log10 transformed.</p

Interaction effects of ‘season’ and ‘location’ on culicine larval densities.

<p>Interaction effects of ‘season’ (x axis) and ‘location’ (family of lines) on mean total culicine larval densities (±se) per container and mean total densities of each immature development stage, II-IV instar larvae and pupae (y axis), April to October 2011 and 2012.</p

Main effects and interaction effects of ‘location’ and ‘year’ on mean total of all mosquitoes and of Culicinae and main and interaction effects of ‘season’ and ‘location’ on Culicinae mosquitoes.

<p>Main effects and interaction effects of ‘location’ and ‘year’ on mean total of all mosquitoes and of Culicinae and main and interaction effects of ‘season’ and ‘location’ on Culicinae mosquitoes.</p