- Author: Kathy Keatley Garvey
Everyone's talking about the drones.
You know, the unmanned aerial vehicles (UAV). Those flying robots cruising over our heads--some with cameras for journalistic and research purposes and others with "need-to-know" purposes.
But in the entomological world, the word "drone" usually means a male honey bee. Or a fly. A drone fly.
To the untrained eye, the common drone fly (Eristalis tenax) looks somewhat like a honey bee, and flies somewhat like a honey bee. It feeds off pollen and nectar.
But the larva is known as a rattailed maggot and feeds off bacteria in drainage ditches, manure or cess pools, sewers and the like.
Like a worker honey bee, the adult drone fly is a pollinator and is often mistaken for a honey bee. Unlike a honey bee, however, it has one set of wings, large eyes, stubby antennae, and a distinguishing "H" on its abdomen.
Coming soon to a field near you--a drone (flying robot) and a drone fly (flying fly). Neither causes diseases nor sucks blood.



- Author: Kathy Keatley Garvey
The drone fly, aka European hover fly, aka syrphid fly, doesn't get as much press as the other drone, the unmanned aircraft.
But the drone fly (Eristalis tenax), about the size of a honey bee and often mistaken for a honey bee, makes for great in-flight photos. It's sort of the Fat Albert of the Blue Angels.
Last weekend we watched a drone fly (distinguished by the "H" on its abdomen), hovering over an Iceland poppy (Papaver nudicaule). The rain-battered poppy certainly wouldn't have won any gold awards in a county fair's garden show.
But to the drone fly, bent on foraging, this was gold. It emerged with "gold dust" (pollen) on its head.
Yes, its larva are known as rat-tailed maggots and yes, they frequent manure piles, sewage drainage ditches and other water-polluted areas.
But the adults are pollinators. Significant pollinators, at that.



- Author: Kathy Keatley Garvey
How many times have you encountered a "honey bee" on the Internet, in a book, magazine, newspaper or other publication, and found a syrphid fly misidentified as a honey bee?
It's truly amazing how often syrphid flies are mistaken for honey bees.
Take the Eristalis tenax, a European hover fly quite established in the United States.
And quite "established" as a honey bee.
It's a syprhid, in the family Syrphidae; in the subfamily, Eristalinee; in the tribe Eristalini; in the subtribe Eristalina; and in the genus, Eristalis.
It's typically called a drone fly (it's about the size of a male honey bee or drone) but some folks also call it a hover fly, a flower fly or a syprhid.
No matter what you call it, it's a fly, not a bee.
Now to the "rats" part.
Their larva is known as a rat-tailed maggot. Its long tail-like structure resembles that of a rat or a mouse. Sometimes it looks like a corn dog with a tail. Or a butterscotch-colored lollipop with a tail.
Rat-tailed maggots live in such habitats as sewers, manure pile pools, drainage ditches and other badly polluted areas. Which is probably why you don't see them. (And if you did, you'd know it wasn't a corn dog with a tail.)
But in the adult stage, they're pollinators. They go where the honey bees go.
You'll find the adult drone flies nectaring on such flowers as lavender, catmint, daisies, sunflowers and yarrow, and hear people exclaiming "Look at the bees!"
I'm waiting for someone to say "They used to be rat-tailed maggots."



- Author: Kathy Keatley Garvey
Indeed, to the untrained eye, the drone fly (Eristalis tenax) appears to be a bee. It's not; it's a fly.
Native pollinator specialist Robbin Thorp, emeritus professor of entomology at UC Davis, calls the drone fly "The H Bee." That's because there's an "H" on its abdomen (see photo). Like all flies, however, it can be distinguished by one pair of wings and stubby antennae. The larva of the fly is a rat-tailed maggot that lives in drainage ditches, pooled manure piles and other polluted water. The adults are floral visitors. Pollinators.
The "H Bee" was among the pollinators that Thorp discussed at the UC Davis Pollinator Gardening Workshop, hosted March 6 by the California Center for Urban Horticulture.
Extension apiculturist Eric Mussen of the UC Davis Department of Entomology and Nematology, switched from bee mimics (drone flies, syrphid flies and other insects) to talk about the "real" honey bees, Apis mellifera, which European colonists introduced to what is now the United States in 1622. "The honey bees' biggest problem today is malnourishment," he said. "A single honey bee colony requires an acre of bloom to meet its nutritional needs each day," he said.
The queen can lay 2000 eggs a day in peak season. "One cell of honey and one cell of pollen make one bee."
He urged the participants to "try to plant for late summer and fall bloom, when honey bees in California are having a hard time finding nectar and pollen resources."
Mussen cautioned that bees are subjected to toxic pollens and unnatural toxins (pesticides). Plants poisonous to bees include the California buckeye (Aesculus californica) death camas (Toxicoscordion venenosum), corn lily (Veratrum californicum) and some locoweeeds (Astragalus spp.)
Pesticides inside the hive (used to control varroa mites) and outside the hives can be fatal. However, he said, "any kind of pesticide a bee encounters--there's always a physiological change."
Following the morning-long speaker presentations, the participants visited the UC Davis Arboretum Teaching Nursery on Garrod Drive to check out and/or purchase Arboretum All-Stars and other plants, and they toured the Häagen-Dazs Honey Bee Haven, a half-acre bee friendly garden on Bee Biology Road that is under the wing of the UC Davis Department of Entomology and Nematology. The garden is located next to the Harry H. Laidlaw Jr. Honey Bee Research Facility.
Among those traveling the longest distance were Lake Tahoe UC Master Gardeners Lynne Broche and Bonnie Turnbull and Turnbull's 14-year-old daughter, Jessie Brown, a junior Master Gardener and an avid insect photographer.
The ceanothus blooming in the haven especially drew the attention of the workshop participants. Insects foraging in the ceanothus included two so-called "H bees"--the honey bee and its impostor, the H-marked drone fly.


- Author: Kathy Keatley Garvey
Poet Gertrude Stein, who coined "A rose is a rose is a rose," probably would have liked it.
Julia Child, maybe not.
We purchased a "Sparkle and Shine" yellow rose, related to the Julia Child Rose, last May at the rose sale sponsored by the California Center for Urban Horticulture, University of California, Davis. It's drawing quite a bit of attention from insects in our yard.
And not just from honey bees, earwigs and spottted cucumber beetles.
From flies.
We recently spotted this drone fly (Eristalis tenax) foraging among the blossoms. Startled by the camera movement, it kept flying off, only to return within seconds.
At first glance, non-entomologists would probably identify it as a honey bee. It's a floral visitor, right?
Right. But not all floral visitors are flies, and not all pollination involves bees.
Wikipedia says that in its natural habitat, the drone fly "is more of a curiosity than a problem, and the adults are benficial pollinators."
It's the larva, the red-tailed maggot, that makes some people shudder. The larvae, as Wikipedia says, live "in drainage ditches, pools around manure piles, sewage, and similar places containing water badly polluted with organic matter."
So from a pool around a manure pile to a beautiful Sparkle and Shine yellow rose. Who would have thought?


