Flies, Pacific Northwest
The Hoverfly belongs to a large family of small to big flies. They are true flies or Diptera, with only one pair of wings.
Hoverflies have spots, bands or stripes, of yellow, brown against a dark-colored background, sometimes with dense hair covering the body surface.
Their fast flight, motionless flight and in some species, their size are astonishing feats.
Some Hoverflies are among the biggest flies. Many species are very colorful. It is not always that easy to identify hoverflies. Some thick-headed flies and bee flies are similar and dark coloration makes it hard to identify them correctly at a glance. Bee flies tend to have longer hair.
Many are seen in the summer mixing with butterflies, bees, bumble bees, and other flower dependent insects. Male hovers tend to emerge and mature first, earlier in the season to ensure reproduction is successful. Many species are useful to the gardener since their larvae eat pest aphids on garden plants and crops.
The degree to which they contribute to pollination is also ironically poorly investigated but no doubt are important for carrot, onion and fruit trees.