Flower Fly on Zizia

We are getting a lot of these little pollinators on our Golden Alexanders (Zizia aurea) but they are easy to miss.  They land on the flower head and walk across the blossom but don't appear to collect any pollen on their bodies.  I use the term flower head because the actual parts are a lot more confusing to a guy just chasing insects.  The technical description below of the blossoms, "umbel and the umbellets" sounds more like a rock band in the 70's.

"Each compound umbel is about 2-3" across, and consists of about 12 umbellets. There are about 21 flowers in each umbellet. Each flower is about 1/8" (3 mm.) across; it has 5 incurved yellow petals."
Illiinoiswildflowers  In other words, its complicated.

Golden Alexander is a member of the carrot family.  What could be more pleasant and nutritious?  It turns out this is a family with some deadly relatives.  It contains everything from the food to the lethal carrot, Poison Hemlock that spreads over our roadsides.

Golden Alexander

Our pollinator doesn't seem to care about those details.  This is the Eastern Calligrapher (EC) Toxomerus geminatus.  It is a Syrphid fly because it is in the family Syrphidae, a large group with over 800 species in North America alone.  They’re also called “flower flies” because of the places we find them, and “hover flies” because that is what they do.  EC is very common around here and is patient enough that although it is only a quarter inch long, I can get up close to identify it with a hand lens as it continues to hover or feed.

This EC is a male, identifiable by the large eyes.  "The males have bigger eyes - they have to find the females who are hanging out in a flower bar, just waiting to be picked up.  The guys have to be able to tell the difference in sexes to avoid wasted time and embarrassing encounters."  It has yellow and black aposematic colors that say "stay away, I can hurt you" but it is all a bluff as it has no stinger.  If a predator could count it would realize this is a fly with two wings, not a bee or wasp with four.

Toxomeris politus larva - Bug Lady

EC Larva - MJ Hatfield

EC adults feeds on nectar and pollen and even honeydew if it finds aphids.  There is a debate on what the larva eat but some sources suggest that they eat aphids attacking plants.  Finding Syrphid larva and raising them for identification is a very specialized sport as they come in a lot of different shapes.  My favorite was the T. politus above which I extracted from my favorite insect blogger, the Bug Lady who writes an entertaining description of EC in this blog.