Does differential predation permit invasive and native mosquito larvae to coexist in Florida?

Abstract

1. The hypothesis that selective predation on larvae of the invasive Aedes albopictus (Skuse) could account for its stable coexistence with the native mosquito species and inferior competitor Ochlerotatus triseriatus (Say) in Florida treeholes and container systems was tested experimentally.2. Functional responses of the two dipteran predators Toxorhynchites rutilus (Coquillett) and Corethrella appendiculata (Grabham) were evaluated separately for A. albopictus and O. triseriatus prey. Both predators exhibited type II functional responses and consistently consumed more of the invasive species. Handling time of T. rutilus feeding upon O. triseriatus was significantly longer than when preying upon the invasive species.3. When either predator species was offered varying ratios of the two prey species, A. albopictus was consumed preferentially. The absence of a prey ratio effect on preference indicated that switching probably does not occur.4. The higher maximum feeding rate upon, and preference for, A. albopictus suggests that differential predation may foster coexistence of the invasive and native mosquito prey species in Florida.