When the environment changes rapidly, insect populations can adapt to their environment, move to a new environment, or perish. Locusts are grasshoppers that can move as needed, transitioning from a phase where they avoid other locusts to a massive swarm of locusts moving together from one region to another (migration). Because locust swarms can destroy crops, a lot of research has been conducted on locusts to understand the control of migration. These insects are able to change quickly to develop the ability to migrate when they choose access to distant resources over other life needs, such as immune function and reproduction. However, despite the devastating impact locusts can have on ecosystems (including crops) and human communities (destruction of crops impacts farmer livelihoods), little is known about how environmental factors trigger this change in locusts. It is known that in a variety of animals, the availability of various nutrients affects growth, reproduction, and immunology. While nutritional variation is expected to be a key factor, no prior research has evaluated how nutritional variation affects the ability of insects to migrate. This CAREER project will combine local and international educational opportunities, as well as lab and field research to test how nutrition, population density, and historical habitat variability interact to affect migration, immune function, and reproduction of locusts. The results will be used to develop sustainable management and policy recommendations and will be provided to global partners to improve livelihoods, and human and environmental health.
This CAREER project will answer fundamental questions about the mechanisms that determine whether migration occurs: (1) What are the physiological trade-offs associated with migrating vs. not migrating, specifically among capacities to migrate, fight disease, and reproduce? (2) How do population density and nutritional quality (specifically protein:carbohydrate ratio of the diet) affect these tradeoffs? (3) How does historical environmental variability affect population-level variation in responses to migration-inducing stimuli? (Are populations that have evolved with more variable habitats more likely to migrate?) Answering these questions will broadly advance our understanding of why and how animals migrate, how to predict migratory responses to global change, and provide fundamental insights into the ecophysiology of one of the most economically important insect pests. A combination of the PI's long-term research partnerships established locust colonies and rearing facilities at ASU, and education plan engaging university trainees, farmers, and international scholars will allow for unprecedented integrated lab and field research-connecting individual biological function with continental-level landscapes. In addition, the PI and her team will develop a research-intensive undergraduate course where students will engage in novel research and co-author peer-reviewed papers from this project. To meet the need to train more biologists and pest management officials in locust biology, particularly from underrepresented groups, this project will support a workshop at Arizona State University.
National Science Foundation, CAREER
This grant was cofunded by the Integrative Ecological Physiology Program in the Division of Integrative Organismal Systems and The Population and Community Ecology Cluster in the Division of Environmental Biology.