Justin's research focuses on plant-insect chemical ecology. His current research includes: (1) understanding the role floral scent plays in plant-pollinator interactions and how environmental stressors alter scent and pollinator attraction, (2) examining tree chemistry to understand host selection and resistance to bark beetles, and (3) exploring chemically-mediated interactions between invasive plants and herbivores.
Justin also has projects on assessing “pollinator-friendliness” of native plants for restoration, determining management and disturbance effects (e.g., bark beetle outbreaks) on pollinators, and the taxonomy and biodiversity of long-legged flies (Diptera: Dolichopodidae).
Chemistry plays a critical role in most species interactions and underpins community structure and function. I seek to understand chemistry's function in the World and exploit it to better manage and restore ecosystems. One example is the chemical interactions between bark beetles and trees. Our work revealed that host-searching mountain pine beetles are repelled by volatiles emitted by Great Basin Bristlecone pine (but strongly attracted to odors from other pine species). Understanding what it is about this blend of odors that repels beetles could allow development of new strategies for managing this important forest insect. Another example is biological control, the only tool capable of managing widespread exotic plant invasions. However, some biological control agents obtain approval and are released, but fail to impact weed populations. A better understanding of the interactions between biocontrol agents and their invasive host plants is needed to identify the factors which promote or limit successful biocontrol. My approach is to apply the chemical ecology of plant-herbivore interactions to classical biological control of weeds - two fields which have largely progressed independently to date. Chemistry plays a central role in determining ecological outcomes between plants and insects and should provide information that can be used to better predict which potential agents are most likely to be effective.
1. Chemical Ecology of interactions between parasitic plants, their host plants, and insect herbivores. 2. Biological control and chemical ecology of the tritrophic system consisting of the wheat stem sawfly, host plants, and natural enemies. 3. How bark beetle attack alters tree chemistry and how this affects flammability to better predict and manage wildfires. 4. exploiting sagebrush chemistry to improve restoration.
This research will better position us to devise and apply management to address important issues including invasive plants, pollinators, and bark beetles. It will also advance our basic understanding of the ecology of plant-insect interactions.