Posts Tagged: hover fly
“If you were an aphid on a head of lettuce, a hoverfly larva would be a nightmare. They are voracious eaters of aphids. One larva per plant will control the aphids.”
That's what organic researcher Eric Brennan of the Agricultural Research Service (ARS), U.S. Department of Agriculture, told reporter Jim Robbins in a recently published New York Times article.
Headlined "Farmers Find Organic Arsenal to Wage Wars on Pests," the news story drew attention to why natural enemies are "key to the organic approach."
Brennan is based in Salinas Valley, known as "The Salad Bowl of America." It's reportedly where 80 percent of Americans get their greens.
And it's where the lettuce aphid gets its lettuce.
To help resolve the problem, organic farmers are planting alyssum in their lettuce beds. Hover flies "live in the alyssum and need a source of aphids to feed their young, so they lay their eggs in the lettuce," Robbins wrote. "When they hatch, the larvae start preying on the aphids."
Could be that the "salad days" are over for the aphids--thanks to Brennan, alyssum and hover flies.
Aren't syrphid flies grand?
Syrphid flies, aka hover flies or flower flies (family Syrphidae), are especially grand in a Calandrinia grandiflora, aka rock purslane.
Often mistaken for honey bees, these insects hover over flowers, wings spinning like helicopters, and then dart inside a blossom to feed on pollen and nectar.
We spotted a brightly colored syrphid on a rock purslane in our garden last Sunday. It appeared in no hurry to leave its host.
Is it true that this colorful fly is in the same order (Diptera) as the common housefly? It is.
Hover flies are found everywhere in the world except Antarctica. For a look at some of the species, check out BugGuide.Net. The site contributors are self-described naturalists "who enjoy learning about and sharing our observations of insects, spiders, and other related creatures."
Another great source is entomologist Robert Bugg's 25-page booklet, "Flower Flies (Syrphidae) and Other Biological Control Agents for Aphids in Vegetable Crops," published in May 2008 by the University of California, Division of Agriculture and Natural Resources (UC ANR). You can download it for free by accessing this page.
A hover fly, not a bee.
Passersby admiring the gazania blooming outside the Harry H. Laidlaw Jr. Honey Bee Research Facility at the University of California, Davis, might think that all the insects that frequent the golden flowers are bees.
Hover flies, aka syrphids or flower flies, also find the gazania quite attractive.
A member of the Aster family and native to South Africa, the gazania is a drought-tolerant ground cover.
Perfect for bees.
Perfect for hover flies.
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.
Hover fly on rock purslane
Ready for Take-Off
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?
The dandelion blossom belongs to the fly.
On the Rim