Response of Aedes aegypti and Aedes albopictus (Diptera: Culicidae) Survival, Life History, and Population Growth to Oak Leaf and Acorn Detritus.

Abstract

Aedes albopictus (Skuse) (Diptera: Culicidae) and Aedes aegypti (L.) (Diptera: Culicidae) are invasive container mosquitoes that are of potential medical importance in the southern United States. Seeds (acorns) and leaves from oak trees can contribute seasonally to the detritus of larval container habitats. Herein, we examined the effect of acorns and leaves from the southern live oak (Quercus virginiana Mill.), which has a concomitant range with these mosquitoes, on the population performance of Ae. aegypti and Ae. albopictus. Three levels of acorns and oak leaves were used (0.99, 1.98, and 7.94 g), along with two mixtures (leaf + acorn: 0.50 + 1.48 and 1.48 + 0.50 g). Tannins, secondary plant metabolites that effect herbivory, were measured across all treatment levels; nitrogen and carbon was also measured for detritus and representative females. Survival, female mass, development time, and λ' (per capita rate of population increase) were used to evaluate population performance of both species. Detritus amount but not type led to differences in tannins; however, these differences did not correspond to differences in performance. Acorns had higher carbon and C:N than leaves. Survival for both species was lower in medium amounts of acorns. Female mass varied with leaf amount, whereas development time differed between amounts of pure leaf and acorn. λ' was lowest in medium and high acorns compared with leaves or mixtures. Thus, acorns do appear to limit mosquito survival and affect population growth, suggesting that inputs of this common detritus type may negatively affect container Aedes production.