Hide the cactus! There's a Mexican cactus fly in our midst.
A large black fly hovers over a Mexican sunflower (Tithonia) in our bee garden and then drops down to sip some nectar. At first glance it looks like a carpenter bee but this one hovers like a syrphid fly, aka flower fly or hover fly.
"Hover fly," I say.
Entomologists Martin Hauser, Lynn Kimsey and Robbin Thorp quickly identified the critter.
Hauser, senior insect biosystematist with the Plant Pest Diagnostics Branch of the California Department of Food and Agriculture, says it's in the genus Copestylum (with over 350 species in the new world) and figured it to be the species, mexicanum, commonly known as the Mexican cactus fly.
Said Lynn Kimsey, director of the Bohart Museum of Entomology and professor of entomology at UC Davis: "Nice, this is actually a kind of syrphid flower fly, better known as a cactus fly. The larvae breed in rotting cactus tissue."
Native pollinator specialist Robbin Thorp, emeritus professor of entomology, also figured it to be a Mexican cactus fly, Copestylum mexicanum. "It's commonly known as a cactus fly (Syrphidae, Tribe Volucellini). "It used to be in the genus Volucella, But now it's in the genus Copestylum."
This fly is not small. It's about 3/4 of an inch long. It lays its eggs in rotting plant material "and they really like rotting cacti," Hauser commented. "As far as I know, they only go into dying cacti and do not attack healthy cacti…. But there is actually not much known about their biology."
The resident cacti expert at our house is worried, showing his best prickly pear expression. He quickly canvasses the yard. Whew! No rotting cacti. All thriving and in good health.
So far, so good...
A freeloader. A moocher. A sponger.
That's the freeloader fly.
A praying mantis is polishing off the remains of a honey bee. Suddenly a black dot with wings edges closer and closer and grabs a bit of the prey.
So tiny. So persistent. So relentless. That's the freeloader fly.
Don't look at the mangled honey bee. Don't look at the hungry praying mantis.
Look at the freeloader fly. Wait a few seconds and you'll see another.
The scene: a camouflaged praying mantis is tucked beneath some African blue basil leaves and the light is fading fast. (You could say I took this image "on the fly.")
Senior Insect Biosystematist Martin Hauser of the Plant Pest Diagnostic Branch, California Department of Food and Agriculture (CDFA) identified these "freeloader flies" as family Milichiidae and "likely the genus Desmometopa." See Wikipedia.
They are so tiny, Hauser says, that the mantids, spiders and Reduviidae (think assassin bugs) "don't bother chasing them away or even trying to eat them."
Hauser pointed out images of freeloader flies from BugGuide.net: http://bugguide.net/node/view/23319/bgimage
And look at all the freeloaders on this prey: http://bugguide.net/node/view/512989/bgimage
Back in March of 2012, agricultural entomologist Ted C. MacRae who writes a popular blog, Beetles in the Bush, posted an image of an assassin bug eating a stink bug. Check out all the flies engaging in what he calls kleptoparasitism--stealing food.
Everybody gets fed. Nobody leaves hungry.
Orange zinnias not only brighten our autumn days but glorify our gardens.
And when there's a bug on the zinnias, all the better.
This insect, identified by Senior Insect Biosystematist Martin Hauser of the California Department of Food and Agriculture, is a fenale Eristalis hirta, aka hover fly or flower fly. It belongs to the family Syrphidae, order Diptera and is one of about 99 species in the genus.
Look for them on a flower near you. And oh, yes, they're pollinators, pollinating such fruits as apples, pears, blackberries and raspberries.
And speaking of plants and insects, if you're around UC Davis on Wednesday, Nov. 6, don't miss the UC Davis Department of Entomology and Nematology seminar by Patrick Abbot, an associate professor of biological sciences at Vanderbilt University, Nashville. He'll speak on “Cooperation and Conflict at the Plant/Insect Interface” from 12:10 to 1 p.m. in 122 Briggs. Plans are to record the seminar for later posting on UCTV.
It's appropriate during National Pollinator Week to remember that.
We spotted this newly emerged green bottle fly (below) nectaring on lavender last week in our yard.
It seemed out of place among the honey bees, leafcutter bees and carpenter bees working the blossoms.
We didn't recognize it as a newly emerged green bottle fly, Lucilla sericata. But fly experts Martin Hauser of the California Department of Food and Agriculture and Terry Whitworth of Washington State University, did.
Family Calliphoridae. Genus Lucilla. Species sericata.
"This looks like a Calliphoridae which just emerged, so the wings are still folded," said senior insect biosystematist Hauser.
Said Whitworth, an adjunct professor of entomology at WSU who maintains the websites birdblowfly.com and blowflies.net: "This is a teneral fly, not fully sclerotized. You can see it just emerged and the wings have still not extended so identification can be tough. However, the shot clearly shows three postacrostichals which almost certainly makes it the common, cosmopolitan Lucilia sericata."
Forensic entomologist Robert Kimsey of UC Davis marveled at the newly emerged fly. "Something dead in your yard?" he quipped.
"No," we said. "But the cat caught a rat the other day. We disposed of it quite quickly." Not the cat, the rat.
'Course, flies aren't known for being pollinators. They're better known--and rightfully so--for disposing of carrion and as the key tool in forensic entomology. They're also used in medical science as maggot therapy. And for art: one of Kimsey's former graduate students, forensic entomologist Rebecca O'Flaharty, coined the term "Maggot Art" (trademarked) and that's one of the activities at the annual UC Davis Picnic Day. Graduate and undergraduate students in the Department of Entomology and Nematology show youths how to dip a maggot in water-based, non-toxic paint, place it on white paper, and let it crawl. Voila! Maggot Art! Suitable for framing...
Everything in life--and death--has a purpose.
You may have noticed this little floral visitor in your garden.
It might appear to be a bee, a common mistake to the untrained eye or those who think that all floral visitors are bees.
But it's a fly, and flies are pollinators, too!
This fly, from the genus Eristalis, family Syrphidae (hover flies), order Diptera, is probably Eristalis stipator, says fly expert Martin Hauser, senior insect biosystematist with the Plant Pest Diagnostics Branch, California Department of Food and Agriculture.
In its larval form, Eristalis, found in aquatic habitats, is known as a rat-tailed maggot, due to its appendage that resembles a snorkel.
Next time you see this little fly on a flower, you can tell your friends "In its larval stage, it's a rat-tailed maggot."
As they widen their eyes and raise their eyebrows, you can add: "But in its adult stage, it's a pollinator."