For my dissertation, I tested whether the differences in antipredator behavioral responses of an invasive and a native mosquito to native predators, affect the distribution and invasive success of the invading species. Larvae of the mosquito Toxorhynchites rutilus and the midge Corethrella appendiculata prey upon aquatic insects such as larvae of invasive Aedes albopictus and the native mosquito Ochlerotatus triseriatus.

1) I tested A. albopictus and O. triseriatus behavior in response to predation risk cues from T rutilus. O. triseriatus adopted low-risk behaviors but A. albopictus did not change its behavior. Unlike A. albopictus, O. triseriatus adopted low risk behaviors even in predation water prepared by feeding A. albopictus to the predator.

2) I tested whether the antipredator responses of O. triseriatus are threat sensitive. The frequencies of resting and surface (antipredator behaviors) declined, whereas frequency of filtering (foraging behavior) increased, with a decrease in concentration of predation cues.

3) I tested how A. albopictus and O. triseriatus responded to a size-selective predator, C. appendiculata, and how species-specific prey behaviors toward this predator may affect the interactions among these species. Larvae that thrashed on container bottoms had a higher risk of being captured by C. appendiculata. O. triseriatus, but not A. albopictus, adopted low risk behaviors in response to water-borne cues of this predator. Both prey species reduced risky behaviors in the physical presence of the predator, but O. triseriatus showed a stronger response. Second instars of both species were more vulnerable to predation by C. appendiculata than 3rd instars, and 3rd instar A. albopictus were more vulnerable than O. triseriatus. All instars of O. triseriatus showed similar reduction of risky behaviors.

4) I compared the abundances of O. triseriatus, A. albopictus, and C. appendiculata and behavioral responses of A. albopictus between different habitats and sites. The abundance of C. appendiculata was greater in tree holes (forested areas), and was positively associated with O. triseriatus and negatively associated with A. albopictus. Aedes albopictus were dominant and their abundances in developed urban areas were twice as those found in forested areas. There was no difference in A. albopictus antipredator behavior between the habitats or among sites.

5) I tested the potential for A. albopictus to evolve antipredator responses. Behavioral responses of this species did not show any divergence after 4 generations of controlled laboratory natural selection in the presence of C. appendiculata.