Mosquito Ecology
Background
Plant-held water bodies including pitcher plants, tree holes, bamboo internodes, and water tight leaf axils (i.e., phytotelmata) have long served as important microcosm systems for testing ecological theory in part because of their logistical tractability. The boundaries of local communities are well defined, they are inhabited by relatively simple communities including dipteran larvae, protists and rotifers, dynamics can be monitored over practical spatiotemporal scales, and they are often amenable to field manipulations. Tree hole mosquitoes in particular have been the focus of many studies because they are often vectors for diseases influencing human health. My research uses tree hole metacommunities as a model system for linking the active movement and oviposition behavior of tree hole mosquitoes to population, community, and ecosystem properties.
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| Tree Hole | Water-filled Containers |
Projects
Movement & Oviposition Behavior
The purpose of this study was to perform a mark-release-recapture to examine the movement and oviposition behaviors of the eastern tree hole mosquito, Ochlerotatus triseriatus (Say), and test the importance of these behaviors in determining population distribution. By relating vegetation characteristics to the location and number of recaptures, I found that mosquitoes preferred to oviposit in habitats with more understory vegetation and a more open canopy.
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| Capturing mosquitoes
with backpack aspirator |
Marked mosquito |
Population Dynamics
Originally, the preference - performance hypothesis was formulated to explain relationships for phytophagous insects, which are generally not believed to reach densities high enough for offspring to experience competition. My research with tree hole mosquitoes has demonstrated that not only do tree hole mosquitoes experience density dependence, but that density dependence has important implications for the preference – performance relationship. Experimental manipulations demonstrated a divergence of fitness among habitats with increasing density, which may select for consistent but weak preferences for particular habitats. This would generate a negative preference – performance relationship when population densities are low, but a positive relationship when population densities are high.
Community Dynamics
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| Food Web of Tree Holes in NH |
My previous studies demonstrated that tree hole mosquitoes may exhibit habitat and oviposition preferences that are a function of the abiotic environment. Because mosquito larvae are top predators in tree hole communities, non-random distributions of their populations could have important implications for local and regional community dynamics. In this study, I performed a series of observational and manipulative experiments using tree hole communities as a model system for examining predator distributions with respect to environmental gradients at multiple spatial scales, and testing the effects of predation on spatial community structure. Results demonstrated that tree hole mosquitoes and many other dipteran larvae occupying tree holes exhibit habitat associations and that predation by these larvae greatly decreased the richness and abundance of prey in predator-occupied habitats.
Metacommunity Dynamics
Four different conceptual models of metacommunities have been proposed, termed patch dynamic, species sorting, mass effect and neutral. In collaboration with Dr. Marcel Holyoak at UC Davis and Dr. Phil Lounibos at the Florida Medical Entomology Laboratory in Vero Beach, FL, I evaluated the characteristics and long-term dynamics of tree hole mosquitoes in Florida and compared them to those predicted by the four metacommunity perspectives. Briefly, we found strong elements of species sorting, but with considerable turnover, as predicted by the patch dynamic model. Our results did not match a single model and therefore caution against overly simplifying metacommunity dynamics by using one dynamical characteristic to select a particular metacommunity perspective.
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| Life Cycle of a Mosquito |