Syrphid Fly – Volucella bombylans

Syrphid Fly – Volucella bombylans

Syrphid Fly - Volucella bombylans

Volucella bombylans is a non-native apparently introduced from Europe [3].  This male specimen, measuring 13mm, was found along a forest path, actively feeding on flower nectar. They look for all the world like small bumble bees – the species epithet refers to the bumble bee genus Bombus for this reason.

This fly is engaging in Batesian mimicry of a venomous critter, the bumble bee. Batesian mimicry is advantageous for an insect because it allows a non-venomous or harmless species to gain protection from predators by imitating the appearance of a venomous or poisonous species.

Syrphid Fly plumose antennaePlumose antennae and pubescent compound eyes

Batesian mimicry reduces to zero the venom-delivery cost for the mimicking insect: Producing venom is energetically costly for an insect. It requires resources and energy to synthesize, store, and maintain venom glands and the associated apparatus for venom delivery, such as specialized stingers or mouthparts. Non-venomous insects that mimic venomous ones can allocate these resources to other essential functions, such as reproduction or growth, rather than investing them in venom production.

Syrphid Fly - Volucella bombylans

Who’s zooming who? This fly might also be mimicking robber flies in the genus Laphria (below), themselves eminent bumble bee mimics.

Robber fly Laphria thoracicaRobber fly Laphria thoracica

A single hoverfly larva can consume a substantial number of aphids during its development. Their high appetite for aphids helps control aphid populations effectively.

Flies Index

North American Insects & Spiders

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