Ah, the little intricacies of life...

We were walking along a stretch of the coastal town of Bodega Bay when we spotted something we'd never seen before: a bubble on a syrphid fly.

Syrphid flies, also known as hover flies or flower flies, are pollinators, just like honey bees. As floral visitors, syrphids are often mistaken for bees. They're not. They're flies.

But what was the bubble?

Several of our UC Davis entomologists weighed in.

"Weird, I wonder if that's an egg," said one entomologist. "Looks like the ovipositor is extended."

Said another: "If this were a honey bee, I would suggest that you shot your first defecation photo." (Spoken like the true honey bee expert he is!)

And another: "My guess is that droplet is fly (note: brace yourself--here comes the "p" word) poop, composed mostly of digested pollen grains that the flies commonly feed on. If you look closely at the abdomen of these flies, you often see the gut outlined with yellow or orange through the semi-translucent membrane areas of the abdomen due to the pollen they have ingested."

We asked fly expert and  senior insect biosystematist Martin Hauser of the California Department of Food and Agriculture's Plant Pest Diagnostic Branch for an I.D. of this syrphid fly. "A female Sphaerophoria," he said.

And, oh, yes, the bubble is not an egg. It's the "p double oh p" word with pollen inside. Hauser pointed out that the eggs are oval and white, so the yellow bubble is not an egg. Check out this photo of syrphid eggs on the bugguide.net website, Hauser said. And here's a image on bugguidenet.com of the syrphid fly ovipositing.

Mystery solved!

Sounds like a good question for an Entomology 101 quiz...

Or the Linnaean Games...

“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.

Not.

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.