Beer-flavoring compounds guide insects

The compounds that give beer some bitter flavor notes also show up in garden flowers–but with more sober jobs.

A Hypericum flower that looks plain yellow (above) contains pigments that, in ultraviolet light (below), darken its center and buds. Eisner

Eisner

Chemical ecologist Thomas Eisner of Cornell University found some of the bitter beer compounds, called DIPs for dearomatized isoprenylated phloroglucinols, in flowers of six species of the genus Hypericum.