Meet the sawflies of the genus Dolerus (family Tenthredinidae)—striking wasp look-alikes that are, in reality, completely harmless. While their bold shapes and dark, often metallic bodies might make you hesitate, these gentle insects possess no stinger. Instead, they get their common name from the female’s highly specialized, saw-like ovipositor, which she uses to delicately slice open plant tissue to lay her eggs. Unlike actual wasps, which are often ruthless hunters, Dolerus larvae are strict vegetarians. Looking almost identical to caterpillars, they spend about a month feeding on grasses and sedges. The adults are equally peaceful, drifting through early spring meadows to sip on flower nectar and tree sap, acting as accidental but highly beneficial pollinators. These cold-tolerant insects are among the very first to emerge after winter, sometimes flying on chilly, damp spring days. They complete just one life cycle per year, spending the long winter resting quietly in the soil as pupae. I crossed paths with this gorgeous, pitch-black specimen in early June. Surrounded by the quiet green of a Swedish forest, it kindly sat still and let me take a few stunning close-ups before going about its day.
