Patrick Grof-Tisza, Kathy (Hughes) DeerInWater, and Eric LoPresti are current grad students, and Heather Kharouba is a current postdoc in my lab.
Kathy (Hughes) DeerInWater
I am interested in how herbivores juggle avoiding predation and plant defenses. What information do herbivores use to make important host plant selection decisions? Specifically my research investigates how herbivores use volatile chemicals released by damaged plants to gain information about the quality of potential host-plants. Eventually I plan to combine plant volatiles and predator cues to test the influence of both bottom-up and top-down effects on herbivore decision-making. I will explore questions related to this topic using upland cotton (Gossypium hirsutum) and some of its associated herbivores and their predators in both the lab and in the field. My research will help us to better understand the complexity of information available to and from all three trophic levels and how each level utilizes this information.
My research concerns how trophic forces structure the spatial distribution of populations and how these forces vary across spatial and temporal scales. Additionally, I seek to understand how organismal movement may interact with these structuring forces to influence within-patch dynamics. My study system consists of a generalist herbivore, a tiger moth (Platyprepia virginalis; Lepidoptera: Arctiidae), and its primary parasitoids and host plants. A twenty-plus year data set exists for the population of P. virginalis within the Bodega Marine Reserve on the northern California coast. Combining this historical data set with my ongoing manipulative field experiments and observational studies provides a rare opportunity to identify and possibly explain long-term patterns and gives context to more recent population trends.
I am currently studying the ecological consequences and evolutionary patterns of chemical defenses excreted by plants. A staggering variety of plants have excretory structures that may have defensive roles, including salt glands, salt bladders, epicuticular waxes, extra-floral nectaries, and resin glands. While external plant defenses are chemically diverse and have different modes of action, their interactions with other organisms may make them a distinct group from the more widely studied internal chemical defenses. I study chenopods, a diverse and extremely widespread family of plants with a unique excretory system (“salt bladders”) that has defensive roles. Members of this family include quinoa, spinach, beets, and the saltbushes, as well as some noxious weeds such as pigweed and tumbleweeds.