- Author: Kathy Keatley Garvey
The warmth of the sun and the lure of nectar beckoned the hover flies or flower flies to our bee friendly garden.
We saw this one nectaring the rock purslane (Calandrinia grandiflora) last weekend. Native pollinator specialist Robbin Thorp, emeritus professor of entomology at UC Davis, identified it as "family Syrphidae, probably the genus Platycheirus."
It stood quite still, sipping the nectar and soon honey bees and a mason wasp joined it.
But for a minute, it seemed to have a "Mine" sign slapped on the blossom.
- Author: Kathy Keatley Garvey
Squatters' rights.
A dandelion poking through the rocks near Nick's Cove on Tomales Bay, in Marshall, Sonoma County, seemed an unlikely host for squatters' rights.
It first drew a tiny bee, barely a quarter-inch long. It was a female sweat bee, family Halictidae, genus Lasioglossum, subgenus Dialictus.
She claimed the dandelion all to herself.
Not for long.
Another insect shadowed the dandelion and swooped down to feed.
It was a hover fly, family Syrphidae. (Probably a Eristalinus aeneus, observed UC Davis pollinator specialist Robbin Thorp, emeritus professor of entomology at UC Davis.)
So on one dandelion: a fly and a bee.
The fly is bigger. But the bee can sting. The sting, however, is rated only 1.0 on the Schmidt Sting Pain Index compiled by (now retired) entomologist Justin O. Schmidt at the Carl Hayden Bee Research Center, Tucson, Ariz.
Fight or flight?
Flight.
The dandelion blossom belongs to the fly.
- Author: Kathy Keatley Garvey
If you see a caterpillar near a cluster of aphids, don't squash it. It could very well be the larva of a syrphid or hover fly (family Syrphidae) and it's eating aphids.
What do they look like? I happened to capture an image of a tiny syrphid larva on a rose leaf, and sure enough, it was eating aphids.
Community ecologist Louie Yang, who joined the UC Davis Department of Entomology faculty last year, has also photographed syrphid larvae. He recognized this one right away.
If you want to learn more about syrphid flies, be sure to read Flower Flies (Syrphidae) and Other Biological Control Agents for Aphids in Vegetable Crops, Publication 8285 (May 2008), UC Division of Agriculture and Natural Resources. It's primarily the work of UC Davis entomologist Robert Bugg; with expertise offered by Ramy Colfer, chief organic agricultural researcher, Earthbound Farms, Salinas; William Chaney, farm advisor, UC Cooperative Extension (UCCE) Monterey County; Hugh Smith, farm advisior, UCCE Santa Barbara and San Luis Obispo counties; and James Cannon, UC Davis computer resource specialist.
In the publicaiton overivew, Bugg writes that "Flower fly development involves complete metamorphosis, including egg, three larval stages, puparium, and adult. Adults of many flower fly species resemble stinging bees and wasps. This phenomenon is called Batesian mimicry, indicating that palatable organisms resemble or 'mimic' unpalatable models. Worldwide, there are many aphidophagous syrphid speices."
"Adult hover flies require honeydew or nectar and pollen to ensure reproduction, whereas larvae usually require aphid feeding to complete thir development."
Below, you'll see a syrphid larva doing what it does best: eating aphids.
- Author: Kathy Keatley Garvey
Last Saturday the rock purslane in our bee friendly garden drew a honey bee, several hover flies and one spotted cucumber beetle.
A hover fly landed on a blossom, only to find a spotted cucumber beetle there first.
- Author: Kathy Keatley Garvey
Ah, rain!
Ah, liquid precipitation!
Just when we were feeling drought-stressed, the weather forecast turned to rain.
I don't know if "the rain in Spain falls mainly on the plain," but the rain in Northern California fell squarely on our bee friendly garden last weekend.
The honey bees weren't there, but the hover flies, aka syrphids and flower flies (family Syrphidae), were.
Winter is an etching, spring a watercolor, summer an oil painting and autumn a mosaic of them all. --Stanley Horowitz
