Monarch Butterfly Ecology, Behavior, and Vulnerabilities in North Central United States Agricultural Landscapes

Movement Ecology of Adult Western Corn Rootworm: Implications for Management

Movement of adult western corn rootworm, Diabrotica virgifera virgifera LeConte, is of fundamental importance to this species' population dynamics, ecology, evolution, and interactions with its environment, including cultivated cornfields. Realistic parameterization of dispersal components of models is needed to predict rates of range expansion, development, and spread of resistance to control measures and improve pest and resistance management strategies. However, a coherent understanding of western corn rootworm movement ecology has remained elusive because of conflicting evidence for both short- and long-distance lifetime dispersal, a type of dilemma observed in many species called Reid's paradox. Attempts to resolve this paradox using population genetic strategies to estimate rates of gene flow over space likewise imply greater dispersal distances than direct observations of short-range movement suggest, a dilemma called Slatkin's paradox. Based on the wide-array of available evidence, we present a conceptual model of adult western corn rootworm movement ecology under the premise it is a partially migratory species. We propose that rootworm populations consist of two behavioral phenotypes, resident and migrant. Both engage in local, appetitive flights, but only the migrant phenotype also makes non-appetitive migratory flights, resulting in observed patterns of bimodal dispersal distances and resolution of Reid's and Slatkin's paradoxes.

Tracking technologies: advances driving new insights into monarch migration

Understanding the rules of how monarch butterflies complete their annual North American migration will be clarified by studying them within a movement ecology framework. Insect movement ecology is growing at a rapid pace due to the development of novel monitoring systems that allow ever-smaller animals to be tracked at higher spatiotemporal resolution for longer periods of time. New innovations in tracking hardware and associated software, including miniaturization, energy autonomy, data management, and wireless communication, are reducing the size and increasing the capability of next-generation tracking technologies, bringing the goal of tracking monarchs over their entire migration closer within reach. These tools are beginning to be leveraged to provide insight into different aspects of monarch biology and ecology, and to contribute to a growing capacity to understand insect movement ecology more broadly and its impact on human life.

Monarch butterfly-breeding habitat restoration: how movement ecology research can inform best practices for site selection

Population dynamics, persistence, and distribution are emergent properties of animal movement behavior and the spatial configuration of resources. Monarch butterflies are a vagile species with an open-population structure. Selecting locations for monarch butterfly- breeding habitat restoration that aligns with natural movement behavior will facilitate efficient habitat utilization across the landscape, increase realized fecundity, and ultimately support increases in the overwintering population size in Mexico. Obtaining and interpreting empirical movement and space-use data through field and laboratory studies are fundamental to this effort. To gain insights into population responses at larger, spatially explicit landscape scales, the results from empirical studies can be incorporated into simulation models. Together, empirical and simulation studies can inform options for creating functional connectivity of monarch butterfly-breeding habitats. Given currently available information, we synthesize studies for the eastern monarch butterfly to illustrate how an improved understanding of movement ecology can assist in planning conservation practices.