The willow leaf beetle (likely Phratora laticollis) is a small, dazzling insect native to Europe belonging to the leaf beetle family (Chrysomelidae). Unlike its cousin, the brassy willow leaf beetle—which steals defensive chemicals from the plants it consumes—Phratora atrovirens manufactures its own chemical security system. Its larvae produce a toxic, autogenous secretion from their own glands to deter predators. Both adults and larvae feed heavily on trees in the willow family (Salicaceae), and the larvae are famously known as “leaf skeletonizers.” Instead of devouring the whole leaf, they consume only the soft tissue, leaving the tough, vein-like network completely untouched and turning the foliage into intricate, lace-like patterns. I met this fascinatingly cute beetle during a forest walk in Järfälla, Sweden.