The Effects of Milkweed Induced Defense on Parasite Resistance in Monarch Butterflies, Danaus plexippus.

Many plants express induced defenses against herbivores through increasing the production of toxic secondary chemicals following damage. Phytochemical induction can directly or indirectly affect other organisms within the community. In tri-trophic systems, increased concentrations of plant toxins could be detrimental to plants if herbivores can sequester these toxins as protective chemicals for themselves.

Orthogonal fitness benefits of nitrogen and ants for nitrogen-limited plants in the presence of herbivores.

Predictable effects of resource availability on plant growth-defense strategies provide a unifying theme in theories of direct anti-herbivore defense, but it is less clear how resource availability modulates plant indirect defense. Ant-plant-hemipteran interactions produce mutualistic trophic cascades when hemipteran-tending ants reduce total herbivory, and these interactions are a key component of plant indirect defense in most terrestrial ecosystems. Here we conducted an experiment to test how ant-plant-hemipteran interactions depend on nitrogen (N) availability by manipulating the presence of ants and aphids under different N fertilization treatments.

Host Diet Affects the Morphology of Monarch Butterfly Parasites.

Understanding host-parasite interactions is essential for ecological research, wildlife conservation, and health management. While most studies focus on numerical traits of parasite groups, such as changes in parasite load, less focus is placed on the traits of individual parasites such as parasite size and shape (parasite morphology). Parasite morphology has significant effects on parasite fitness such as initial colonization of hosts, avoidance of host immune defenses, and the availability of resources for parasite replication.

Fitness costs of animal medication: antiparasitic plant chemicals reduce fitness of monarch butterfly hosts.

The emerging field of ecological immunology demonstrates that allocation by hosts to immune defence against parasites is constrained by the costs of those defences. However, the costs of non-immunological defences, which are important alternatives to canonical immune systems, are less well characterized. Estimating such costs is essential for our understanding of the ecology and evolution of alternative host defence strategies.

Disease ecology across soil boundaries: effects of below-ground fungi on above-ground host-parasite interactions.

Host-parasite interactions are subject to strong trait-mediated indirect effects from other species. However, it remains unexplored whether such indirect effects may occur across soil boundaries and connect spatially isolated organisms. Here, we demonstrate that, by changing plant (milkweed Asclepias sp.