- Author: Kathy Keatley Garvey
(Continued from the July 13th Bug Squad)
Our resident crab spider, family Thomisidae, appears to be an extremely poor hunter. She waits, camouflaged in the lavender patch, as bees buzz around her. They dart away when she lunges at them.
So here I am, a crab spider, as hungry as can be
Does anyone out there feel sorry for me?
"Yes," say the arachnologists. The apiculturists say "no."
Well, I'll just hang out in the lavender and keep lying low.
Hey, looky there! I'm going to fast-track that bee.
Sorry, I am who I am, and I gotta be me.
The next day, success. Or, as they say, it was "a good day for the spider and a bad day for the bee."
It was also a good day for a freeloader fly (family Milichiidae, probably genus Desmometopa). These flies always seem to appear seconds after a spider (or praying mantis) nails its prey. No dinner reservations required.
Other bees mark themselves "safe" from the crab spider. For now.
And life goes on. For the crab spider. For the freeloader flies.
- Author: Kathy Keatley Garvey
We have bright faces in our Vacaville, Calif., pollinator garden.
The bright faces are usually that of assorted bees and butterflies nectaring on members of the sunflower family: Mexican sunflower (Tithonia) and blanketflowers (Gaillardia).
But we did not expect to see this bright face: a banded garden spider, Argiope trifasciata. Bright face? Argiope is Latin for “with bright face” while trifasciata is Latin for “three-banded.”
The Argiope trifasciata spider is found throughout much of the United States and Canada. It's also in Central and South America, Australia, the Mediterranean region, Africa, Sri Lanka, the South Pacific Islands, and China, according to Spiders of North America, which informs us that scientists have identified a combined total of 4000 spider species in the United States and Canada.
Argiope trifasciata is just one of them, but what a beautiful spider it is. Clever and cunning, too.
It had crafted a web inches from the ground between a showy milkweed, Asclepias speciosa, and bluebeard (Caryopteris clandonensis) amid patches of Mexican sunflower patch and African blue basil.
Exactly where the bees are.
It snared two of them one morning and wrapped them for later consumption.
Meanwhile, an opportunistic and hungry freeloader fly, family Milichiidae and maybe genus Desmometopa, figured the spider ought to share its prey. It stopped to feed on the wrapped bee.
So, in actuality, there were two bright faces in the garden--the banded garden spider and the freeloader fly.
The faces of the wrapped honey bees--not so much.
- Author: Kathy Keatley Garvey
There is such a thing as a free lunch. And a free breakfast. And a free dinner.
And a free snack.
That is, if you're a freeloader fly.
If you've ever watched a spider snare a bee or other insect in its web, and wrap it like a fit-to-be-tied holiday present, you've probably seen tiny little freeloader flies dining on the prey.
They are so tiny--usually 1 to 3 mm in length--that it takes a keen eye to spot them if they're not moving. The eyes are often red though "this need not be obvious because many species of the flies are small and dusky."
The close-up below is a hand-held photo taken with a Canon EOS 7D with a MPE-65mm lens.
Freeloader flies belong to the family Milichiidae. The close-up below may be in the genus Desmometopa, but it's difficult to tell by the image, says Martin Hauser, senior insect biosystematist with the Plant Pest Diagnostics, California Department of Food and Agriculture.
As it turned out, the spider dropped its prey and the freeloaders flies didn't have to leave the table.
- Author: Kathy Keatley Garvey
The next time you see a spider eating a bee snared in its web, look closely.
The spider may not be alone. It may have a dinner companion.
A freeloader fly.
The common name, "freeloader fly," refers to the Milichiidae family. These flies are very tiny, about 1 to 3 mm in length, so you may not notice them.
We took these photos with a 105mm macro lens last Friday at the Häagen-Dazs Honey Bee Haven, a half-acre pollinator garden planted next to the Harry H. Laidlaw Jr. Honey Bee Research Facility on Bee Biology Road, University of California, Davis.
These flies, identified by senior insect biosystematist Martin Hauser of the Plant Pest Diagnostics Branch, California Department of Food and Agriculture, are curious little critters. Note the large heads and the red eyes ("the eyes of Milichiidae are often red, though this need not be obvious because many species of the flies are small and dusky," according to Wikipedia.)
Bees are everywhere in the garden and so are the orbweavers--on the zinnias, cosmos, roses and the Mexican sunflowers.
Predator catches prey, and here come the freeloader flies. There is such a thing as a free lunch.
Sharing a meal with a hungry spider, however, may have dire consequences for the freeloaders. They may become a side dish to the spider's main course.