REU Projects

To see a mentor's website, click on their name!

Bumble bee foraging patternsDavid E. Carr (Research Professor of Environmental Sciences and Director of Blandy Experimental Farm, University of Virginia).  Bees rely almost exclusively on flowering plants for their food resources. Floral nectar is the primary source of carbohydrates, and pollen is the primary source of protein and lipids. Over the past several years, my REU students have been working on patterns of pollen collection by bees in greenhouse experiments and field studies. We are trying to understand cues that bees use in making foraging decisions and how bees respond to spatial and temporal variation in the availability of pollen rewards in their environment. Ultimately, our goal is to link bee foraging decisions to the evolution of cues and rewards and to bee population dynamics.

Community ecology of aquatic insects and population structure of aquatic turtlesPatrick W. Crumrine (Associate Professor of Environmental Science and Biological Sciences, Rowan University). Temporary ponds and wetlands are dynamic ecosystems that are often colonized by a diverse assemblage of aquatic organisms trying to take advantage of the lack of fish predators to complete their life cycle. I use a combination of observational, comparative, and experimental methods to study the factors that shape community structure in these aquatic systems. I am most interested in how size structure (variation in body size) influences the outcome of predator prey interactions in assemblages of larval aquatic insects, mainly dragonflies, diving water beetles and water bugs. Recent REU students at Blandy have also investigated how structural habitat complexity influences these interactions. Future REU projects in this area could examine how variation in structural habitat complexity interacts with other variables such as water temperature and connectivity between habitat patches to influence the outcome of size-structured predator prey interactions. Opportunities also exist for REU students to explore how individual variation in other traits such as activity level influence predation. Regardless of the specific question student’s address in their project, a significant amount of time will be spent in the field collecting and identifying aquatic insects and students will gain experience carrying out mesocosm-style experiments commonly used in aquatic community ecology.

Multi-trophic interactions of plants and insects Rebecca Forkner (Associate Professor of Biology, George Mason University).  Chemicals not only determine the color and beauty we observe in nature, they also control the outcome of many species interaction. Following in the tradition of May Berenbaum, Tom Eisner, and David Lee, Dr. Forkner researches the role of plant chemistry in the evolution and community ecology of plant-insect interactions.  Her work includes projects that investigate the contribution of insects to autumn color and abscission chemistry in deciduous trees, the importance of plant mutualists to the chemistry of flower color, and the influence of host plant chemistry on insect behavior and morphology.  Her REU students’ projects frequently incorporate a combination laboratory chemical assays, greenhouse experiments, insect rearing or bioassays, and fieldwork. Past REU students have investigated butterfly-host plant interactions and rhizobia-plant-insect interactions.  Possible upcoming REU projects involve chemical ecology in microbe-plant-insect interactions of a) the ant-plant Chamaecrista and its herbivores or b) Colias or Vanessa butterflies and their Fabaceae host plants.  Given Dr. Forkner’s background in a variety of study systems, including spiders, ants, bees, butterflies and moths, and fireflies, students are also encouraged to develop novel collaborations with Rebecca and other REU faculty.

Perceptual and cognitive processes governing egg recognition in wild birdsDaniel Hanley (Assistant Professor of Biology, George Mason University). Avian brood parasitism occurs when one bird (a parasite) lays its eggs in another birds’ nest (a host). This alternative reproductive tactic allows parasites to offload parental care on their hosts, which must either pay these costs or adapt tactics to avoid parasitism. Many hosts have adapted mechanisms to avoid the costs of parasitism through recognizing and removing the young of brood parasites (either as eggs or young). Hanley’s research focuses on the perceptual and cognitive mechanisms underlying these host defense systems. His research focuses on how hosts respond to natural variation in eggshell phenotypes, with a particular emphasis on the visual abilities of host species. Students will have the opportunity to develop field studies that reveal the decision-making process in these wild animals. Although there are several potential research directions, students can focus on the perceptual mechanisms that give rise to choices (using novel technologies we are developing) or focus on the cognitive processes that are employed by hosts (through careful experimental manipulation). Your REU research can help uncover the perceptual-cognitive processes that shape these inter-species interactions.

Ecological consequences of human-induced ecological changeKyle J. Haynes (Research Associate Professor, University of Virginia). Haynes is interested in understanding how human-induced environmental change at local to global scales impact ecological processes. Artificial light at night, better known as “light pollution”, is increasingly recognized as a major threat to biodiversity and ecosystem functioning. Recent REU students working with Haynes have studied how artificial light at night affects plant growth or the movement, feeding, and spatial distributions of insects and other arthropods. Possible upcoming REU student projects include field experiments to study the impacts of artificial light at night on a) herbivory and predation in communities of grassland arthropods, b) the movement and mating behaviors of bioluminescent fireflies, or c) the growth and physiology of plants.

Ecological and evolutionary responses of plants to variable soil environments Mary A. McKenna (Associate Professor of Biology, Howard University). My current research with REU students focuses on ant-plant mutualisms in black-eyed pea (Vigna unguiculata). This species is critically important for global food security, particularly in arid regions with rain-fed agriculture where climate change is expected to significantly increase hunger and famine. Black-eyed pea can avert malnutrition among subsistence farmers because of the high nitrogen content of its leaves (12%) and seeds (25%).  Symbiosis with N-fixing bacteria allows the plant to tolerate and replenish nutrient-poor soils. Many flowering plants use a portion of the energy they obtain from photosynthesis to produce floral nectar, because the reproductive benefits they obtain by attracting pollinators outweighs the costs of lost energy for vegetative growth.  Black- eyed pea sacrifices additional energy to produce nectar on vegetation; these “extrafloral nectaries” (EFN) attract ants that harvest the nectar.  Since ants are typically territorial, they often defend plants with EFN against herbivorous insects, providing plants with more energy for reproduction. We are exploring the possibility that investment in EFN results in higher reproductive success in black eyed pea. Other plant community studies in the McKenna lab seek to understand how heritable traits vary in different soil environments and how these traits contribute to evolutionary fitness. Recent studies at Blandy examine ways serpentine plants “forage” for soil nutrients and how they defend themselves against herbivory by deploying chemical, physical and inorganic (toxic metal) defenses. McKenna’s lab also focuses on community-level responses to volatile signals from plants. Plant volatiles influence a host of interactions (above- and below-ground) including relationships between plants and pathogens, herbivores, mutualists, and competitors. Studies at Blandy have explored interactions between mints and nodule-forming legumes that may be important for nutrient cycling and soil fertility in natural and agricultural ecosystems.

Pollinator interactions with plants, parasites and their environment T’ai H. Roulston (Research Associate Professor of Environmental Sciences and Curator of Blandy Experimental Farm, University of Virginia). Native bees form a species-rich, diverse and ecologically important group of insects that support both wild plant reproduction and agricultural productivity. My lab focuses on pollinator interactions with plants, parasites, environmental stresses and each other in order to identify potential drivers of population abundance. Using field surveys as well as RFID technology coupled with other monitoring systems, we use bumble bee observation nests to examine foraging risk and opportunity in the local landscape. Possible REU projects for the coming year include examining how bee foraging efficiency, longevity, and floral host choice are mitigated by factors such as parasitism and pesticide exposure. In choosing a question and outlining research methods, the student will gain experience with native bees, designing research questions, and creating and adapting equipment in pursuit of answers.