What's for dinner?
A crab spider, camouflaged in our lavender patch, didn't catch a honey bee, a butterfly, an ant or a syrphid fly.
No, it nailed a green bottle fly.
We couldn't help but notice. The fly's metallic blue-green coloring stood in sharp contrast to the white spider.
One venomous bite to kill it. And soon the fly, Lucilia sericata, was toast. Milk toast.
Crab spiders don't build webs to trap their prey. They're cunning and agile hunters that spring into action when an unsuspecting prey appears on the scene. They belong to the family Thomisidae, which includes some 175 genera and more than 2100 species. And they're ancient: spiders date back 400 million years ago.
Do you like spiders? You should.
“Spiders are an incredibly diverse group with more than 50,000 species described with probably another 200,000 remaining to yet be discovered,” says spider expert Jason Bond, the Evert and Marion Schlinger Endowed Chair in Insect Systematics in the UC Davis Department of Entomology and Nematology.
It's worth repeating what Professor Bond said about spiders at the Bohart Museum of Entomology open house, “Eight-Legged Wonders,” on Saturday, March 9.
The five good reasons to like spiders:
- Spiders consume 400-800 million tons of prey, mostly insects, each year. Humans consume somewhere around 400 million tons of meat and fish each year.
- Spider silk is one of the strongest naturally occurring materials. Spider silk is stronger than steel, stronger and more stretchy than Kevlar; a pencil thick strand of spider silk could be used to stop a Boeing 747 in flight.
- Some spiders are incredibly fast – able to run up to 70 body lengths per second (10X faster than Usain Bolt).
- Athough nearly all 47,000-plus spider species have venom used to kill their insect prey, very few actually have venom that is harmful to humans.
- Some spiders are really good parents –wolf spider moms carry their young on their backs until they are ready to strike out on their own; female trapdoor spiders keep their broods safe inside their burrows often longer than one year, and some female jumping spiders even nurse their spiderlings with a protein rich substance comparable to milk.
The itsy bitsy spider climbed up the water spout.
Down came the rain and washed the spider out.
Out came the sun and dried up all the rain
and the itsy bitsy spider climbed up the spout again.
It was an itsy bitsy spider.
But it wasn't climbing up a water spout.
It was lurking, waiting for prey, on our Mexican sunflower.
This particular crab spider was quite visible--white on orange. Sometimes they're so camouflaged that you have to look twice to see them. We remember the perfectly camouflaged crab spider on a gold coin flower (Asteriscus maritimus). (See below).
Crab spiders belong to the family Thomisidae, which includes about 175 genera and more than 2100 species. Wikipedia tells us that "The common name crab spider is often applied to species in this family, but is also applied loosely to many other species of spiders. Among the Thomisidae, 'crab spider' refers most often to the familiar species of 'flower crab spiders,' though not all members of the family are limited to ambush hunting in flowers."
If there's any flower that should be crowned "Autumn's Majesty," that would be the Mexican sunflower (Tithonia rotundifolia), aka "Torch."
A member of the sunflower family (Asteraceae), it carries "the torch of life" throughout spring, summer and autumn, but it's especially important in autumn when few plants offer sustenance to insects, especially to migrating monarchs. The colorful annual has been blooming in our yard since April, reaching 10-to 15-foot heights (thanks, drip irrigation).
What loves this delightful orange blossom, besides the human beings who grow it?
Over a weeklong period, we photographed dozens of autumn critters, including monarchs, Gulf Fritillaries, hover flies, honey bees and crab spiders.
Every bee garden needs an "Autumn Majesty" and the Mexican sunflower fills the bill. When it goes to seed, finches and other birds will take what's left.
Dear Crab Spider,
Please don't eat the pollinators. You may help yourself to a mosquito, a crane fly, a lygus bug, an aphid, and a katydid, not necessarily in that order. And more than one if you like. In fact, how about an all-you-can-eat buffet of luscious lygus bugs? So good! Yes, you may tell all your arachnid friends about the nutritious, high-protein meals available just for the taking. Please do. Just don't eat the pollinators.
Crab spiders do not listen. They will eat what they want and when they want it. And they will gorge themselves. They are not interested in joining Weight Watchers. They are Wait Watchers.
For the past several months, crab spiders have been lurking on our blanket flower (Gaillardia). Most of the time, they just sit there, waiting patiently for dinner to arrive. Sometimes it's a long wait--longer than it takes for a waiter to return to your table during a rush-hour holiday lunch.
So, Ms. or Mr. Crab Spider--not sure of the gender, but "Predator" will do--dined recently on a sweat bee, a female Halictus tripartitus. We watched Predator lunge at a honey bee (missed!) and pursue at a male long-horned bee, probably Melissodes agilis.
Our cunning little arachnid no doubt nailed a few others--the "waistline" is a dead giveaway.
A sure-fire way to frighten arachnophobics is the very mention of "spiders"--especially on Halloween.
Spiders aren't insects but arthropods, order Araneae. They have eight legs, which according to some, are seven legs too many. They are also distinguished by their chelicerae with fangs that inject venom.
You've seen them. Black widow spiders. Jumping spiders. Crab spiders. Garden spiders.
If you fear them, there's a name for that fear: Arachnophobia. Wikipedia says that "People with arachnophobia tend to feel uneasy in any area they believe could harbor spiders or that has visible signs of their presence, such as webs. If arachnophobics see a spider, they may not enter the general vicinity until they have overcome the panic attack that is often associated with their phobia. Some people scream, cry, have trouble breathing, have excessive sweating or even heart trouble when they come in contact with an area near spiders or their webs. In some extreme cases, even a picture or a realistic drawing of a spider can also trigger fear."
The general fallacies, as listed by Rod Crawford, curator of arachnids:
- Spiders are insects.
- "Arachnid" is just a fancy name for spider.
- You can always tell a spider because it has eight legs.
- All spiders make webs.
- The orb web (round or "geometric" web) is a "normal" spider web.
- A "daddy-longlegs" is a kind of spider.
- Most spiders could not bite humans because their fangs are too small.
- Any spider species can be found anywhere.
- All spiders are male.
- Spiders are most numerous in late summer.
- You are never more than three feet from a spider.
- Spiders "suck the juices" of their prey, and do not literally eat it.
- Spiders don't stick to their own webs because their feet are oily.
Meanwhile, over at the Bohart Museum of Entomology at the University of California, Davis, plans are underway for an open house themed "Insect Myths." They will focus on spider myths, too.
The event, free and open to the public, is set for Sunday, Nov. 23 from 1 to 4 p.m. in Room 1124 of the Academic Surge Building on Crocker Lane, off LaRue Road. Directed by Lynn Kimsey, professor of entomology at UC Davis, the museum houses a global collection of nearly eight million specimens and is the home of the seventh largest insect collection in North America, and the California Insect Survey, a storehouse of the insect biodiversity. The museum is open to the public four days a week, Monday through Thursday (9 a.m. to noon and 1 to 5 p.m.) but it sponsors special weekend open houses as well.
The remaining schedule:
- Sunday, Nov. 23: “Insect Myths,” 1 to 4 p.m.
- Saturday, Dec. 20: “Insects and Art,” 1 to 4 p.m.
- Sunday, Jan. 11: “Parasitoid Palooza,” 1 to 4 p.m.
- Sunday, Feb. 8: “Biodiversity Museum Day,” noon to 4 p.m.
- Saturday, March 14: “Pollination Nation,” 1 to 4 p.m.
- Saturday, April 18: UC Davis Picnic Day, 10 a.m. to 3 p.m.
- Sunday, May 17: “Name That Bug! How About Bob?” 1 to 4 p.m.
- Saturday, July 18: “Moth Night,” 8 to 11 p.m.
When you attend the Bohart Museum open houses, you'll probably have the opportunity to hold and/or photograph "Rosie," a 24-year-old tarantula. It's one of the critters in the live "petting zoo," which also includes Madagascar hissing cockroaches, millipedes and walking sticks./h3>/span>