Density‐dependent regulation of Aedes cantans (Diptera: Culicidae) in natural and artificial populations

Mortality and size variation (siphon length) in Aedes cantans larvae were examined in natural populations in northern England in 1989 and 1990. Under crowded conditions, density‐dependent competition led to reduction in the size of both larvae and adults and increased larval mortality. Larvae were also maintained in cages in the field at different densities. Results paralleled those for the natural populations in the ponds; larvae maintained at high densities showed increased mortality and reduced size. Possible density‐dependent factors leading to mortality and size reduction include cannibalism and contact inhibition leading to food shortages. The main density‐independent factor contributing to larval mortality was habitat desiccation.