Hypothesis: Genetic variation in plant defence structures a community of herbivores and ultimately mediates co-evolution. Organisms: Common milkweed (Asclepias syriaca) and five natural insect herbivores (seed bug, leaf mining fly, monarch caterpillar and two beetles). Methods: Quantitative genetic field experiment over 2 years, genetic selection analyses, and measurement of five defensive trai...

Alkaloids produced by systemic fungal endophytes of grasses are thought to act as defensive agents against herbivores. Endophytic alkaloids may reduce arthropod herbivore abundances and diversity in agronomic grasses. Yet, accumulating evidence, particularly from native grasses, shows that herbivore preference, abundances and species richness are sometimes greater on endophyte-infected plants, ...

Because herbivores can move away from plants of low quality, induced resistance should affect the spatial distribution of herbivore damage (or herbivores) within or among plants. We used a spatially explicit simulation model and data from a field experiment to examine the effect of induced resistance on the distribution of herbivores and their damage among plants within a population. The model ...

Insect herbivores trigger various biochemical changes in plants, and as a consequence, affect other organisms that are associated with these plants. Such plant-mediated indirect effects often involve herbivore-induced plant volatiles (HIPVs) that can be used as cues for foraging herbivores and their natural enemies, and are also known to affect pollinator attraction. In tightly co-evolved syste...

The fates of 5,975 feces produced by 88 species of reef fishes were monitored at Palau (western Pacific Ocean). At least 4 5 fishes ate fish feces in addition to other foods. Intraspecific coprophagy and autocoprophagy were very rare and most coprophagous interactions were between members of different trophic groups. Fecal material moved through a feeding network of fishes, from carnivores to h...

Herbivores affect plants through direct effects, such as tissue damage, and through indirect effects that alter species interactions. Interactions may be positive or negative, so indirect effects have the potential to enhance or lessen the net impacts of herbivores. Despite the ubiquity of these interactions, the indirect pathways are considerably less understood than the direct effects of herb...

Two venerable hypotheses, widely cited as explanations for either the success or failure of introduced species in recipient communities, are the natural enemies hypothesis and the biotic resistance hypothesis. The natural enemies hypothesis posits that introduced organisms spread rapidly because they are liberated from their co-evolved predators, pathogens and herbivores. The biotic resistance ...