It's Friday Fly Day--and time to post images of a syrphid fly.

Syrphid flies, often mistaken for honey bees, are pollinators, too. 

Also known as flower flies and hover flies, syrphids hover over a flower before touching down. "Most species are predaceous, most commonly on aphids or mealybugs," according to the UC Statewide Integrated Pest Management Program. "Some syrphids prey on ants, caterpillars, froghoppers, psyllids, scales, other insects, or mites. About 100 to 400 aphids can be fed upon by each aphid-feeding larva before it pupates, but this varies by the mature size of the syrphid relative to the aphids' size."

They are easily distinguished from honey bees because (1) bees don't hover, and (2) syrphids have only one pair of wings, while bees have two. "Their large eyes and short antenna also give them away, notes Kelly Rourke in a U.S. Forest Service article on "Syrphid Fly (Sphaerophoria philanthus). The absence of pollinium, or pollen sacs, is more difficult to see, but is another difference from a bee. Of the nearly 900 species of flower flies (family Syrphidae) in North America, most have yellow and black stripes."

Several years ago we captured images of a syrphid fly and an Asian lady beetle (Harmonia axyridis) on a rose bush in our Vacaville pollinator garden.

The scenario: Aphids were sucking plant juice on one end and secreting honey dew on the other end. The lady beetle was feasting on the aphids and getting sticky from all that honey dew.

Then along came a syrphid, a female Scaeva pyrastri, as identified by senior insect biosystematist Martin Hauser of the Plant Pest Diagnostic Branch, California Department of Food and Agriculture. It hovered over the lady beetle and then dropped down to lick the honey dew from the beetle's head.

'Twas a happy day for the lady beetle and the syrphid fly, but not so much for the aphids. 

Entomologist Andrew Young, who researches syrphid flies, recently presented a seminar to the UC Davis Department of Entomology and Nematology. The seminar is online.

Have you ever seen a syrphid, aka hover fly or flower fly, that resembles a bumble bee?

Volucella bombylans is a fascinating fly that engages in identify theft.  Of a bumble bee. It's a "wanna bee."

At first glance, it looks very much like a bumble bee, the Bombus melanopygus edwardsii, according to the late Robbin Thorp (1933-2019), distinguished emeritus professor of entomology at the University of California. Unlike a bumble bee, however, the fly has short stubby antennae and two wings instead of four. And, of course, it cannot sting.

Most of the species in the genus are inquilines, that is, they lay their eggs in bumble bee and wasp nests, and the larvae consume the host larvae.

We were fortunate to see a Volucella species recently in Vacaville. There's only one valid species of Volucella in North America, Volucella bombylans, according to Andrew Young, a postdoctoral fellow at the California Department of Food and Agriculture who addressed the UC Davis Department of Entomology and Nematology at a Feb. 5 seminar (pre coronavirus pandemic). "However, DNA evidence points to this being a species complex. So, I think it would be most accurate to call it Volucella bombylans complex right now."

If you have a chance, listen to Young's fascinating seminar, "The Natural History of Syrphidae: From Pollinators To Parasitoids." You watch it free here. Lynn Kimsey, director of the Bohart Museum of Entomology and UC Davis professor of entomology introduced him.

His abstract: "Syrphidae (Dlptera) is a species-rich family of true fly, with over 6200 described species worldwide," he says in his abstract. "Often known as flower flies or hover flies, syrphlds are likely the most significant group of pollinators outside of the bees--especially in Arctic climates. While research into their pollination-related behavior is still nascent, other aspects of flower fly biology have been relatively well-studied."

"Adults of many species are well-known for their impressive mimicry of stinging Hymenoptera, and known larvae display a degree of habitat diversity that is unusually broad for a single family of Diptera. Many larvae are predators on soft-bodied insects such as aphids, and therefore, show potential for crop-pest management, while others are aquatic filter-feeders that may have value in waste-management applications."  

Young studied Syrphidae in the lab of Stephen Marshall, professor of entomology at the University of Guelph, Ontario, Canada. Marshall and Young are among the six co-authors of Field Guide to the Flower Flies of Northeastern North America" (Princeton University Press, 2019), a book described as "a groundbreaking guide to flower flies in North America."

Andrew Young, a UC Davis postdoctoral researcher at the California Department of Food and Agriculture (Photo by Andrew Young)

You've probably seen them hovering over flowers, which is why syprhids are commonly called "hover flies" or "flower flies."

Enter Andrew Young.

He's a UC Davis postdoctoral researcher with the Department of California Food and Agriculture (CDFA) and he researches syrphids.

Young, who specializes in Diptera taxonomy and phylogenetics at CDFA, will present a seminar to the UC Davis Department of Entomology and Nematology on "The Natural History of Syrphidae: from Pollinators to Parasitoids" at 4:10 p.m., Wednesday, Feb. 5 in 122 Briggs Hall, off Kleiber Hall Drive.

"Syrphidae (Dlptera) is a species-rich family of true fly, with over 6200 described species worldwide," he says in his abstract. "Often known as flower flies or hover flies, syrphlds are likely the most significant group of pollinators outside of the bees--especially in Arctic climates. While research into their pollination-related behavior is still nascent, other aspects of flower fly biology have been relatively well-studied."

"Adults of many species are well-known for their impressive mimicry of stinging Hymenoptera, and known larvae display a degree of habitat diversity that is unusually broad for a single family of Diptera. Many larvae are predators on soft-bodied insects such as aphids, and therefore, show potential for crop-pest management, while others are aquatic filter-feeders that may have value in waste-management applications." (See UC Integrated Pest Management Program website on syrphids; in their larval stage, they feed on aphids.)

Young says he will give an overview of the current understanding of flower fly phylogeny, followed by an exploration of the varied many adult and larval natural histories known to the group. He will emphasize "many of the little-known larval life histories that are still actively being discovered by dedicated field researchers. I will conclude by briefly discussing some of my past, present and future flower fly research."

Young studied Syrphidae in the lab of Stephen Marshall, professor of entomology at the University of Guelph, Ontario, Canada. Marshall and Young are among the six co-authors of Field Guide to the Flower Flies of Northeastern North America" (Princeton University Press, 2019), a book described as "a groundbreaking guide to flower flies in North America."

From the Princeton University Press website: "Flower flies are, along with bees, our most important pollinators. Found in a varied range of habitats, from backyard gardens to aquatic ecosystems, these flies are often overlooked because many of their species mimic bees or wasps. Despite this, many species are distinctive and even subtly differentiated species can be accurately identified." The guide includes more than 3,000 color photographs and 400 maps, covering all 416 species of flower flies that occur north of Tennessee and east of the Dakotas, including the high Arctic and Greenland. Each species account provides information on size, identification, abundance, and flight time, along with notes on behavior, classification, hybridization, habitats, larvae, and more."

Lynn Kimsey, director of the Bohart Museum of Entomology and professor of entomology at UC Davis, is the seminar host. Community ecologist Rachel Vannette, assistant professor, coordinates the weekly seminars.

Upcoming seminars for the winter quarter (See speaker list) are at 4:10 p.m. on Wednesday in 122 Briggs Hall.

Wednesday, Feb. 12
Kevin Rice, University of Missouri, Columbia
Topic: "Lasers, Drones, and Growth Promoting Fungus: New Technologies for IPM"
Host: Ian Grettenberger, assistant professor

Wednesday, Feb. 19
Mercedes Burns, University of Maryland,>Baltimore County
Topic: (pending) She studies evolutionary ecology of reproductive traits and behaviors, sexual conflict, reproductive polymorphism, arthropod biology
Host: Jason Bond, professor and Schlinger Chair in Insect Systematics

Wednesday, Feb. 26:
Faculty Flash Talks (featuring faculty members Rachel Vannette, Ian Grettenberger, Shahid Siddique, Geoffrey Attardo, Jason Bond)

Wednesday, March 4
Brendon Boudinot, doctoral candidate, Phil Ward lab, exit seminar
Topic: "Morphology and Evolution of the Insects, and the Ancestors of the Ants"
Host: Phil Ward, professor

A honey bee heads for almond blossoms blooming in Benicia, Calif. But sometimes you'll see a bumble bee and other pollinators. (Photo by Kathy Keatley Garvey)

Take Benicia, Solano County. Its little hot spots near the Carquinez Strait--think trees growing near sun-warmed asphalt--yield early almond blooms, often as early as New Year's Day.

At the Matthew Turner Park in Benicia, today, honey bees buzzed around the almond blossoms, gathering pollen and nectar. But the honey bees were not alone.

Yellow-faced bumble bees, Bombus vosnesenskii, were foraging, too.  It's always a treat to see honey bees in the almonds, but it's a double treat to see a bumble bee.

Pollination of California's almond acreage is as intense as it is huge. The 2016 almond acreage totaled 1.2 million acres--940,000 bearing and 300,000 acres non-bearing, according to a report issued in April 2017 by the California Department of Food and Agriculture, in cooperation with the National Agricultural Statistics Service of the U.S. Department of Agriculture. This year, California has more than a million acres of bearing almonds, and each acre requires two bee hives for pollination.  The leading almond-producing counties? Kern, Fresno, Stanislaus, Merced and Madera.

Solano County, of course, doesn't make the list, but when you want to see the early almond blooms, it's the place to "bee."

Which reminds us of the research, Synergistic Effectgs of non-Apis Bees and Honey Bees for Pollination Services, published by an international team of scientists in the Jan. 10, 2013 edition of The Proceedings of the Royal Society B. The researchers, including pollination ecologist Neal Williams of UC Davis,  found that honey bees are more effective at pollinating almonds when other species of bees are present.

When blue orchard bees and wild (non-managed) bees such as bumble bees, carpenter bees and sweat bees, are foraging in almonds with honey bees, the behavior of  honey bees changes, resulting in more effective crop pollination, said lead author Claire Brittain, then of the Neal Williams lab. She earlier worked as a post-doctoral fellow at Leuphana University of Lüneburg, Germany. 

“These findings highlight the importance of conserving pollinators and the natural habitats they rely on,” Brittain told us in a news release. “Not only can they play an important direct role in crop pollination, but we also show that they can improve the pollination service of honey bees in almonds.”

 Agroecologist Alexandra-Maria Klein, now a professor at Leuphana University, served as the project lead while a postdoctoral fellow in the UC Berkeley lab of conservation biologist/professor Claire Kremen.  In fact, Klein and Kremen initiated the project in 2008 and continued working on the project together in 2009 and 2010. Williams joined the team in 2010.

Native pollinator specialist Robbin Thorp, now a distinguished emeritus professor of entomology at UC Davis,  identified 50 different species that the team found. They included bumble bees, small carpenter bees, sweat bees, digger bees, mining bees and blue orchard bees.

Take a look around you during the almond pollination season. The honey bees are not alone.