Climatic variability and landscape heterogeneity impact urban mosquito diversity and vector abundance and infection

Abstract

Abstract. Urban habitat heterogeneity can modify interactions across species and lead to spatially fine grained differences in b-diversity patterns and their associated ecosystem services. Here, we study the impacts of landscape heterogeneity and climatic variability on: (1) the richness and diversity patterns of mosquitoes (Diptera: Culicidae) and (2) the abundance and West Nile virus infection rate of the house mosquito, Culex pipiens, in Chicago, USA. We conducted a four year long study (2005)(2006)(2007)(2008) in 8 sites that captured a gradient of urban heterogeneities. We found a total of 19 mosquito species, a representative sample of mosquito species richness in the area, according to both model estimation (Chao2 6 S.E. ¼ 20.50 6 2.29) and faunal records for Chicago. We found that heterogeneity in the landscape was the best predictor of both mosquito species richness and diversity, with the most heterogeneous landscapes harboring the largest number of species. In general there were no changes in species richness over the years that could be associated with weather patterns and climatic variability (WPCV). In contrast, changes in diversity were associated with WPCV. Our results also showed that WPCV had major impacts on house mosquito abundance and West Nile virus mosquito infection rate (MIR) patterns. Although MIR was independent of mosquito diversity, it was associated with overall mosquito abundance, which had a convex association with species richness (i.e., abundance increases to a point after which it decreases as function of species richness). Finally, our results highlight the importance of considering dominant vector species as part of a community of vectors, whose biodiversity patterns can directly or indirectly impact the risk of infectious disease transmission.

Genetic variations of Chrysomya megacephala populations in Malaysia (Diptera: Calliphoridae)

“…Our finding of low genetic diversity among individuals which were caught from periurban areas, is consistent with similar patterns of low genetic diversity among urban sand fly populations (Shannon Index ranged from 0.08 to 0.34) as revealed by Feitosa et al [37]. It has been suggested that differential adaptation to changes in urban environments and urbanized habitat simplification is related to reduction in genetic variability, as noticed in genetic studies of urban mosquito populations [38] and cricket species [39]. To fully understand the effect of urbanization on C. megacephala, more representative data are required in order to provide genetic support based on the genetic variation of the fly species sampled from both urban and rural areas.…”

Overlap in the Seasonal Infection Patterns of Avian Malaria Parasites and West Nile Virus in Vectors and Hosts

“…pipiens is generally more abundant throughout the study site. 46 Culex pools were screened for Haemosporida parasites following the same protocols described for avian blood samples. Because our data rely on samples of whole-bodied mosquitoes that naturally acquired Plasmodium parasites, we cannot differentiate between infected mosquito hosts and infectious mosquito vectors.…”

Host compatibility rather than vector–host-encounter rate determines the host range of avian Plasmodium parasites

“…Six of the mosquito species were observed to feed on birds. However, only C. pipiens, C. restuans and A. vexans were well sampled, fed on birds and were abundant within the study area [46]. Avian blood meals were recovered from 488 C. pipiens, 172 C. restuans and 15 A. vexans individuals sampled from 2005 to 2007.…”

“…Little information exists on the vectorial capacity of A. vexans. This species was included in this parasite survey because it fed on birds and was abundant in the study site [46]. Individuals were pooled by species, site and date of capture.…”