Aedes albopictus (Diptera: Culicidae) Has Not Become the Dominant Species in Artificial Container Habitats in a Temperate Forest More Than a Decade After Establishment

Abstract

Aedes albopictus (Skuse) (Diptera: Culicidae) is one of the most invasive species globally, and has led to rapid declines and local extirpations of resident mosquitoes where it becomes established. A potential mechanism behind these displacements is the superior competitive ability of Ae. albopictus in larval habitats. Research on the context-dependent nature of competitive displacement predicts that Ae. albopictus will not replace native Aedes triseriatus (Say) (Diptera: Culicidae) in treeholes but could do so in artificial container habitats. Aedes albopictus remains rare in temperate treeholes but less is known about how Ae. albopictus fares in artificial containers in forests. Tyson Research Center (TRC) is a field station composed of mostly oak-hickory forest located outside Saint Louis, MO. The container community has been studied regularly at TRC since 2007 with permanently established artificial containers on the property since 2013. Aedes albopictus was detected each year when these communities were sampled; however, its abundance remains low and it fails to numerically dominate other species in these communities. We present data that show Ae. albopictus numbers have not increased in the last decade. We compare egg counts from 2007 to 2016 and combine larval sample data from 2012 to 2017.We present average larval densities and prevalence of Ae. albopictus and two competitors, Ae. triseriatus and Aedes japonicus (Theobald) (Diptera: Culicidae), as well as monthly averages by year. These data highlight a circumstance in which Ae. albopictus fails to dominate the Aedes community despite it doing so in more human-impacted habitats. We present hypotheses for these patterns based upon abiotic and biotic environmental conditions.

Keywords: Aedes albopictus; Aedes japonicus; Aedes triseriatus; context-dependence; invasive species.

Fig. 1.

(A) Least squares means number of Aedes albopictus eggs laid per day in 500-ml black oviposition cups. The same sampling protocol, in approximately the same locations, was conducted in 2007 and 2016. (B) Least squares means prevalence (% occupancy) of Ae. albopictus in the same egg samples.

Fig. 2.

(A) The prevalence (% occupancy) of Aedes albopictus, Aedes triseriatus, Aedes japonicus, and Toxorhynchites rutilus in larval samples taken in each month, combining the data from 2012 to 2017. Numbers in parentheses are the total number of samples collected. (B) Natural larval densities, in larvae per liter, of these species in artificial habitats at TRC, excluding samples where the focal species was absent.