Relationships between mosquito densities in artificial container habitats, land use and temperature in the Kapiti‐Horowhenua region, New Zealand

Abstract

Land-use change, including deforestation for agriculture and urbanisation, has coincided with increases in vector-borne diseases worldwide. Landuse change is likely to regulate immature (larvae and pupae) mosquito populations through changes in local temperatures owing to manifold changes to the physical environment. However, we still poorly understand the relationship between land use, water temperature, and immature mosquito density. We conducted a field study in the Kapiti-Horowhenua region, New Zealand, to examine the relationship between land use, water temperature, and immature mosquito population dynamics in aquatic larval habitats. Artificial container habitats were sampled for immature mosquitoes in native forest, pastureland and urbanland, at three replicate locations, from October 2002 to April 2003. The endemic species Culex pervigilans constituted 94.5% of all late-instar larvae collected, the remainder being the exotic Ochlerotatus notoscriptus. On average, significantly higher pupal mosquito densities were recorded from urbanland containers compared with pastureland and native forest containers. A similar trend was observed for total mosquito densities, but did not reach statistical significance. Water temperatures in native forest typically did not show as much variation as those in urbanland and pastureland. Pastureland containers had significantly higher maximum and average daily water temperatures and lower minimum daily water temperatures than native forest containers. Using multiple regression analysis, total mosquito densities were best explained by the quadratic effects of maximum daily temperature and average daily temperature. The results of this study show that pastoral and urban development can increase water temperatures in container habitats, and that land-use change may be responsible for higher immature mosquito densities when habitat water temperatures do not consistently exceed a high threshold.

Lethal and Sublethal Impacts of Predaceous BackswimmerAnisops wakefieldi(Hemiptera: Notonectidae) on the Life-History Traits of the New Zealand MosquitoCulex pervigilans(Diptera: Culicidae)

“…Previous work has shown such conditions to be ideal for Cx. pervigilans (Leisnham et al 2006). Containers were then covered with a 1-cm wire mesh to prevent vertebrate animals from drinking or falling into the water.…”

Africanized honey bees in urban environments: A spatio-temporal analysis

“…In some cases, urban environments may provide ideal habitat compared to surrounding natural areas, with some species thriving in cities, such as European starlings (Clergeau and Quenot, 2007) and mosquitoes (Leisnham et al, 2006). Species that thrive in urban environments are often widespread and may be considered pests because of their overlap in resource use with humans.…”

Community structure of artificial container-breeding flies (Insecta: Diptera) in relation to the urbanization level

“…Additionally, two recent works on dipteran communities in artificial containers other than tires, have reported consistent patterns. Hribar et al (2004) found that Culicidae, Chironomidae, Ceratopogonidae, Psychodidae, and Phoridae occurred commonly in artificial and natural containers, sewage treatment plants, and storm drains in Florida (USA), and Leisnham et al (2006) reported that about 60% of the larvae collected with experimental artificial containers in New Zealand belonged to Chironomidae. General findings strongly suggest that the extremely abundant man-made containers present in urbanized areas are being used as breeding habitat for a wide range of aquatic or semi-aquatic dipterans, echoing the composition of taxonomic groups observed in containers in the wild.…”

“…Among urban aquatic assemblages those of streams have received considerable attention (Paul & Meyer, 2001), and immature mosquitoes (Diptera: Culicidae) have been the most studied due to their importance as vectors of diseases (e.g. Cox, Grillet, Ramos, Amador, & Barrera, 2007;Leisnham, Lester, Slaney, & Weinstein, 2006). Among the wide range of aquatic habitats used by mosquitoes (see Service, 1995), artificial or man-made containers, such as water tanks and flower vases, are particularly widespread in urban areas.…”