Syrphid Fly – Volucella bombylans

 Syrphid Fly – Volucella bombylans
Order Diptera | Family Syrphidae – Flower Flies, Hover Flies
A superb bumble bee mimic photographed in the wild at Ogle County in northern Illinois, USA.

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.  These are robust insects and strong fliers, just like their hymenopteran counterparts.

Flies in the family Syrphidae are commonly called flower or hover flies. Syrphidae is a large  group of superbly beneficial insects. Their coloring and movements of most species mimic bees or the vespid wasps, with their bold yellow and black patterns; some syrphids (temnostoma) go so far as to wave their front legs in front of their face to mimic the jointed antennae of aculeate wasps.


Plumose antennae and pubescent compound eyes

Adult syrphids require nectar or honeydew and pollen to ensure their reproduction (as well as to power their physical activities), and larvae generally require aphids for breakfast, lunch and dinner to complete their development. However, in the absence of aphids, larvae of some species can subsist and develop entirely on diets of pollen [1].

Syrphid flies are routinely used as a biological control in the lettuce fields of California's vegetable-producing regions, where the fly's larvae are generally effective in controlling lettuce aphid (Nasonovia ribisnigri). It is primarily the Syrphidae that enable organic romaine growers on California's central coast to produce harvestable crops.

Syrphidae larvae are, in turn, parasitized by wasps in the Hymenoptera families Ichneumonidae and Pteromalidae [1].


Syrphid flies are important pollinators; this fly is fairly well dusted with pollen
References

  1. University of California, DANR, “(Syrphidae) Control Agents for Aphids in Vegetable Crops” .pdf
  2. Bugguide.net, Volucella
Flies of North America – Order Diptera. Flies are prevalent in virtually all habitats, with over 16,000 species in North America. Flies can be distinguished from all other insects in that they only have one pair of normal wings. Most flies have compound eyes and mouthparts adapted for piercing, lapping or sucking fluids.
Syrphidae | Flies Index | Tachinidae | Bee Flies | Robber Flies