REU projects

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).  I use a combination of observational, comparative, and experimental methods to study the factors that shape community structure in aquatic systems. I am most interested in how size structure (variation in body size) influences the outcome of predator prey interactions and community structure in assemblages of larval aquatic insects, mainly dragonflies, diving water beetles and water bugs. I also seek to understand how these interactions are influenced by anthropogenic contaminants such as pesticides and pharmaceuticals. Possible REU projects in this area could examine how pharmaceuticals influence aquatic insect development and top-down vs. bottom up effects of pharmaceuticals on aquatic communities. In addition, I am also interested in the effects of land-use change on aquatic turtle population structure (sex ratio and age structure). REU students would be involved in mark-recapture efforts and could compare population structure across habitat types. A potential REU project could examine the viability of stormwater retention ponds as aquatic turtle habitat.

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). Dr. 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. Summer research opportunities will involve egg rejection experiments, where students will design experimental egg models that can illuminate the decision-making process of these wild animals. For example, if a parasite exclusively exploits a single host species, when that host adapts improved discrimination abilities it selects for ever-improved egg mimicry in their parasite. Traditionally, it was assumed that eggs more easily detected would be removed; however, a series of recent egg rejection experiments suggest that most hosts respond to some colors rather than others. Your REU research can help uncover the perceptual-cognitive processes that shape these inter-species interactions. 

Ecological and evolutionary responses of plants to variable soil environments Mary A. McKenna (Associate Professor of Biology, Howard University).  McKenna’s research explores adaptations of plants to unusual edaphic conditions. Students in the McKenna lab seek to understand how heritable traits vary in different soil environments and how these traits contribute to evolutionary fitness. Some of these studies involve plants from serpentine soil communities that are characterized by high drought stress, low soil fertility, and toxic levels of elements such as Mg and Ni. These edaphic conditions produce “islands” of evolutionary diversity. Serpentine communities include an interesting group of plants (Ni-hyperaccumulators) that evolved an ability to remove and sequester toxic metal from soil into their shoot tissues. 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. In addition to these studies on serpentine ecology, McKenna’s lab also focuses on community-level responses to volatile signals from plants in a variety of edaphic environments. 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. Additional opportunities include evaluating the effectiveness of habitat restorations for providing the key pollen sources used to support bumble bee populations. 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.