Insect diversity

From coffee plantations to urban gardens, UC Santa Cruz environmental studies professor Stacy Philpott has been digging around dirt for decades.

“I look at ways to create win-win situations that protect insect biodiversity and help agriculture thrive,” said Philpott, who holds the Ruth and Alfred Heller Chair in Agroecology and directs the UC Santa Cruz Center for Agroecology & Sustainable Food Systems.

On coffee plantations, her studies have shown that clearing too many trees makes ant diversity decline. Without that biodiversity, plantations lose valuable resources, such as pest control.

Closer to home, Philpott and her students spent three summers studying 19 different Central Coast gardens to learn which factors enhanced insect biodiversity. As urbanization increases, these small green spaces can provide important insect habitats.

Not surprisingly, growing a wider variety of garden plants supported a greater range of insect species. But they also found the surrounding landscape—trees, grasslands, cement, or ground cover—affected biodiversity. For example, in research published in Environmental Entomology, UC Santa Cruz alum Michelle Otoshi showed that spiders were more abundant with garden mulch.

In the future, Philpott will return to coffee plantations to study how changes in bee and ant diversity affect the microbiome of coffee flowers.