Hover flies such as today’s Syrphus ribesii are dead ringers for bees and wasps. Despite their appearance, not only are they harmless, they are valuable pollinators of flowers. Their larvae prey on aphids, while adults feed on the nectar of flowers. Our species of the day is a very common hoverfly found along hedgerows, in gardens and woods.
There are more than 870 species in North America. Many hoverflies mimic the colouration and hairiness of social bees and wasps. This enables them to avoid attack by predators who believe they might be able to sting. This form of mimicry is termed Batesian mimicry. Batesian mimicry is when a harmless species has evolved to imitate the warning signals of a harmful species directed at a predator they both have in common. This form of mimicry is named for its discoverer, the 19th-century English naturalist Henry Walter Bates.