Omnivore diet composition alters parasite resistance and host condition.

Diet composition modulates animals' ability to resist parasites and recover from stress. Broader diet breadths enable omnivores to mount dynamic responses to parasite attack, but little is known about how plant/prey mixing might influence responses to infection. Using omnivorous deer mice (Peromyscus maniculatus) as a model, we examine how varying plant and prey concentrations in blended diets influence resistance and body condition following infestation by Rocky Mountain wood ticks (Dermacentor andersoni).

An omnivore vigour hypothesis? Nutrient availability strengthens herbivore suppression by omnivores across 48 field sites.

Nutrients regulate herbivore growth from the 'bottom-up' via improved plant vigour and food quality. Nitrogen also affects 'top-down' control of herbivores by moderating attraction of predators and the rates at which they consume herbivorous prey. Tri-trophic consequences of nitrogen availability are more challenging to predict among omnivorous natural enemies who feed on both plants and herbivores, limiting our ability to predict net outcomes of nutrient availability in food webs.

Benefits and Risks of Intercropping for Crop Resilience and Pest Management.

To combat climate change, farmers must innovate through ecological intensification to boost food production, increase resilience to weather extremes, and shrink the carbon footprint of agriculture. Intercropping (where alternative crops or noncrop plants are integrated with cash crops) can strengthen and stabilize agroecosystems under climate change by improving resource use efficiency, enhancing soil water holding capacity, and increasing the diversity and quality of habitat for beneficial insects that provide pollination services and natural pest control. Despite these benefits, intercropping has yet to be widely adopted due to perceived risks and challenges including decreased crop yield, increased management complexity, a steep learning curve for successful management, and increased susceptibility to pests.

Weeds Impose Unique Outcomes for Pests, Natural Enemies, and Yield in Two Vegetable Crops.

Weed management requires enormous labor investments from vegetable farmers, yet crops vary in how much weed pressure they can tolerate without yield loss. Moreover, until weeds reach a point where they threaten yield or approach seed production, they can increase biodiversity and provision food and habitat to attract predatory insects. In two related field experiments, we quantified impacts of weed presence and diversity on pests, predators, and biocontrol of both weed seeds and insect prey.

Organic Farming Sharpens Plant Defenses in the Field.

Plants deploy a variety of chemical and physical defenses to protect themselves against herbivores and pathogens. Organic farming seeks to enhance these responses by improving soil quality, ultimately altering bottom up regulation of plant defenses. While laboratory studies suggest this approach is effective, it remains unclear whether organic agriculture encourages more-active plant defenses under real-world conditions.