  |
Family Syrphidae
Toxomerus species
About 6,000 species in 200 genera have been described. Syrphidae are
common throughout the world and can be found on every continent except
Antarctica.
Live adult Syrphid flies photographed in the wild at San Antonio, Texas,
and Winfield, Illinois, USA.
|
|
|
  |
  |
Flies in the
Diptera Family Syrphidae are commonly known as Hover
or Flower flies, after their favorite activity: hovering
around or visiting flowers. They range in size from about 4mm to
over 25 mm (1 inch) and are usually brightly colored yellow and
black, as Batesian mimics of stinging insects such as bees and
wasps. Syrphid flies are important pollinators of flowering
plants, out-pollinating native bee populations in many
ecosystems. Syrphid larvae (maggots) prey on aphids, scales,
thrips, and caterpillars of both butterflies and moths, a
characteristic shared by lady beetles and lacewings. In these
respects, the Syrphidae are viewed as extremely beneficial
insects, and their importance to agriculture cannot be
overstated..
The Syrphidae are abundant nearly everywhere on earth except a
few deserts of Africa and Asia, and extreme southern latitudes.
|
Typical Flower Fly, Toxomerus sp.
|
|
Toxomerus sp.
|
Most hover
flies have large compound eyes that nearly cover the head.
One rule of thumb for identifying hover fly gender is, if
the eyes meet at the top of the head, it's a male specimen.
Each wing has a characteristic fold, or "false vein" which
can be visible to the naked eye - it is located anterior to
the first large vein that runs all the way to the outer
margin of the wing. Of course, being true flies, they have
only one pair of wings, plus the characteristic halteres, or
bulb-like organs that evolved from the second pair of flying
wings. In Syrphid flies, however, the halteres are fairly
inconspicuous. Much has been written about
the Syrphids' mimickry of the bees and wasps. Their bright
yellow and black markings are said to be a Batesian mimickry
of the aposematic (warning) colors sported by the stinging
insects. Some of these flies actually go so far as to use
their front legs to mimic the jointed antennae of the
Vespoid wasps, some are mimics of
bumble bees or honey bees; here are links to pages on those
Syrphidae:
|
|
Bumble Bee Mimic
|
Wasp Mimic
|
Honey Bee Mimic
|
|
|
