Food webs in the garden: feasting flower flies

Syrphid fly and spiderwort

Most people are familiar with flower flies (also called hover flies), and even those who aren't have probably come across one of the 6000 species in the family Syrphidae.  Recognizing flower flies can be difficult, as many species mimic the yellow and black color patterns of bees and wasps.  Despite their warning colors, the pollen feeding adult flies are harmless.  The offspring of some species, however, are fearsome predators.  The are the stuff of nightmares, if aphids would have bad dreams:

This is what I think it would be like to be eaten by 'The Blob'

These maggots might be confused with caterpillars, as they crawl around on leaf surfaces looking for a meal.  Some species will slime their way through a group of aphids, turning around to consume the now stuck insects at a leisurely pace.  In combination with the ladybird beetles, these have really started to lower the populations of aphids on some of our plants.  Had I not planted a diverse garden that supports other aphids for they syrphids to eat, these predators would not have been around to keep the goldenglow aphids in check.

Not your compost's maggot!

 And for those of you that are feeling terrible about my little red plant-sucking friends, I want to ease your worries: I have reason to believe that aphids do not suffer from night terrors.