insects

Human influences on bee pollinators

Bee pollinators are critically important for agricultural and natural ecosystems. Together, wild and managed bee species contribute to the pollination of 80 crops with an estimated annual value of >$200 billion globally, >$29 billion for US agriculture, and >$9 billion for California.

Ecological interactions in managed systems

Anthropogenic effects, notably, habitat conversion from natural to managed systems, can alter interactions between plants, insects, and microbial communities; but these effects on such complex systems are poorly understood. Bacteria and yeast that live in floral nectar affect pollinator visitation and influence floral characteristics.

Thermal stress on monarch butterfly caterpillars

Ongoing climate change will continue to increase the frequency and intensity of extreme climate events, such as heat waves and droughts, with potentially wide-ranging consequences for species interactions. Temperature and moisture availability strongly affect the development of both monarch butterflies and their milkweed host plants, but the role of extreme climate events is less well characterized.

Two plausible hypotheses in the monarch-milkweed system center on heat waves: