Marmalade Hover Fly

Episyrphus balteatus is one of about 6,000 species of hover fly (family Syrphidae) — flies that have evolved striking visual mimicry of stinging Hymenoptera (wasps, bees, hornets). The yellow-and-black banded body, hovering flight, and aggressive-sounding buzz all combine to fool predators that have learned to avoid actual stingers. This is classic Batesian mimicry. Hover flies are completely defenseless — no sting, no toxic chemistry — but the costume works. Behind the disguise, hover flies are extraordinary pollinators: the global Syrphidae family is the second-most important insect pollinator group after bees, and may be more important than bees in cool, temperate regions where bees fly less. Hover fly larvae are aggressive predators of aphids, scale insects, and small caterpillars — a single hover fly larva consumes 200-400 aphids during development. The marmalade hover fly performs one of the largest insect migrations on Earth: billions of individuals cross the Pyrenees and Alps each year between northern and southern Europe, contributing several million tonnes of biomass and pollination services on the way.