Vector mosquitoes increase generation times in the presence of competitors owing to resource limitation
Competition is increasingly recognized as an important regulator of mosquito vectors, with significant implication to disease transmission. Aedes camptorhynchus (Diptera: Culicidae) is the main vector for Ross River virus (Togoviridae: Alphavirus) across Southern Australia. This halotolerant vector is primarily found in salt marsh habitat and coexists with aquatic micro crustaceans, and both aquatic fauna are filter feeders. Resource competition among these organisms may have important implications for natural vector regulation and arboviral transmission, but has not been explored. Here, we investigate the effect of competition on the survival, development and adult size of Ae. camptorhynchus.
We demonstrate that Ae. camptorhynchus growth rate and survival was significantly decreased in the presence of ostracod competitors, and that the effect of competition can be explained by resource limitation. However, there was no effect on the size of emerging adults either in the presence of ostracods or extreme resource limitation. These results provide evidence that biotic interactions such as the presence of aquatic competitors can influence the abundance of emerging vector mosquitoes by influencing their generation time and survival. These effects may have implications for vector-borne disease transmission, and suggest alternative approaches to mosquito regulation.