Proximity to humans
Hoverflies are drawn to humans for various reasons, but when captured, they employ clever tactics to deceive and defend themselves. Discover their surprising strategies below.
Dabbers:
Hoverflies unlike some other flies don't bite but rather have short spongy mouthparts that dab. They dab the surface of your skin, likely seeking salt and moisture. This dabbing habit can tickle. At a flower they will be dabbing up nectar.
Photo Credit: K.Hinchcliffe
Detectors:
Flies are drawn to warmth, and the body heat of humans can attract them. When we breathe, we exhale carbon dioxide, which flies can detect from a distance. Flies are sensitive to various scents, including sweat and other body odours.
Deceivers:
Some hoverflies are skilled deceivers and move the end of their abdomens up and down mimicking wasps and honeybees. They do not sting so it’s safe to let them land on the back of your hand to see this closer. But please check that they are hoverflies before letting them settle. Check for short stubby antennae which hoverflies have… rather than than long antennae of wasps and bees.
Discourager:
Many hoverflies do buzz, often in a high-pitched hum, especially when disturbed, a defence mechanism like bees and wasps. The sounds can vary, with some species, like the Hornet hoverfly, producing a deep buzz and others like the Marmalade hoverfly making a quiet whine. This buzzing is a form of acoustic mimicry to deter predators. Try listening to them with a bat detector at low frequency to amplify the sound.
Defender:
When a bee is caught it gives a high-pitched buzzing sound in the hope that you will drop it, hoverflies mimic this in the hope of the same outcome. I have even observed the Pied Plumehorn (Volucella pellucens) act dead in the hope that you will leave it alone.
Anyone else seen this?
This behaviour is known as thanatosis (playing dead), and is an anti-predator defence found in some insects.
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