Outdoors

Wild Profile: Meet the flower fly

A flower fly collecting nectar from a yellow flower By Paul Reeves Photography/Shutterstock

Oh no, it’s a wasp…or is it a flower fly? Yep, it’s a flower fly. A harmless bug. These black-and-yellow bee-and-wasp imposters don’t sting or bite. Instead, they make it their business to pollinate as many white and yellow spring blossoms as possible. Like honey bees, and native bees, flower flies—along with other flies—are responsible for the proliferation of all kinds of agricultural crops, everything from carrots to cabbage. In fact, non-bees such as flower flies account for 38 per cent of global agricultural pollination. A huge shout-out to you, non-bees!

What are those bees that hover in one spot?

Flower flies are also called hover flies. When you spot one, it’s obvious why: they appear motionless in mid-air as they inspect a prospective bloom. Flower flies have two wings, not four like bees and wasps. But no matter! Those two wings whir at 1,000 beats per second, allowing the insect to hover, helicopter-like, instead of bobbing up and down the way a bee would. Flower flies aren’t as efficient at pollinating as bees are, but they make up for this by visiting more flowers in a shorter amount of time. They seem to prefer to forage in cooler temperatures, when there are fewer bees around.

Spot a group of hover flies? They’re probably males  

In the spring, male flower flies tend to hang out, hovering, over landmarks—paths, hilltops, or shrubs—in order to attract females. Mating, too, involves a lot of mid-air hovering. At least, at first: eventually, a flower fly pair flaps its way over to a nearby perch to continue with the important job of…well, you know. Their bug babies—a.k.a. maggots—spend their youth in puddles, rotting plant life, and animal droppings. They’re translucent and blind, but are excellent predators that feed voraciously on aphids and other tiny crop pests. It’s gruesome—they attack their victims and suck out the liquid innards. So disgusting. But so incredibly helpful to farmers.

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