Salinity tolerance of Aedes camptorhynchus (Diptera: Culicidae) from two regions in southwestern Australia
van Schie, C and Spafford, H and Carver, SS and Weinstein, P, Salinity tolerance of Aedes camptorhynchus (Diptera: Culicidae) from two regions in southwestern Australia, Australian Journal of Entomology, 48, (4) pp. 293-299. ISSN 1326-6756 (2009) [Refereed Article]
Aedes camptorhynchus (Thomson) (Diptera: Culicidae) is widely distributed throughout southwestern
Australia in both coastal and inland sites, and is a vector of Ross River virus (Togoviridae: Alphavirus).
Larvae of this species are most commonly found in brackish to saline and hypersaline waters. In inland
southwestern Australia secondary (anthropogenic) salinisation of agricultural land has led to widespread
increases in the amount and saline standing water and available breeding habitat for Ae.
camptorhynchus. Given the epidemiological significance of this mosquito species it is particularly
important to understand the fundamental biology in order to inform vector management and environmental
remediation strategies. We therefore sought to determine the salinity tolerance of Ae. camptorhynchus
larvae collected from the coastal saltmarshes (coastal) and the southern wheatbelt (inland) of
Western Australia. Ae. camptorhynchus neonate larvae were collected from the two sites and then reared
in seawater or water from the source locations which were manipulated to saline concentrations ranging
from 2.96 to 88.8 parts per thousand (p.p.t.) by dilution or addition of NaCl. Overall, Ae. camptorhynchus
tolerated a wide range of salinities. The majority of Ae. camptorhynchus from the inland site that
survived to adulthood did so at salinities between 8 and 30 p.p.t., whereas the majority of coastal
mosquitoes that survived to adulthood did so in salinities between 22 and 52 p.p.t. Larvae were able to
complete development in salinities up to 62 p.p.t., but none survived to adulthood at higher salinities.
An increase in the number and distribution of Ae. camptorhynchus, associated with rising salinity, in
previously freshwater habitats of inland southwestern Australia could have health consequences by
increasing the potential for Ross River virus activity.