It was a good day for a crab spider.
It was NOT a good day for a honey bee.
It's early evening and here's this bee foraging on a bluebeard plant, Caryopteris x clandonensis, totally unaware of the ambush predator lying in wait.
The hunter and the hunted.
A venomous bite and it's all over.
These spiders, often called the "white death spider," are camouflage artists. They can turn colors, from yellow to white, or white to yellow. You'll often see yellow crab spiders on golden rod Solidago or a predominantly yellow plant, like blanketflower, Gallardia.
"These spiders change color by secreting a liquid yellow pigment into the outer cell layer of the body," according to Wikipedia. "On a white base, this pigment is transported into lower layers, so that inner glands, filled with white guanine, become visible. The color similarity between the spider and the flower is well matched with a white flower, in particular the Chaerophyllum temulum, compared to a yellow flower based on the spectral reflectance functions."
"If the spider dwells longer on a white plant, the yellow pigment is often excreted," Wikipedia says. "It will then take the spider much longer to change to yellow, because it will have to produce the yellow pigment first. The color change is induced by visual feedback; spiders with painted eyes were found to have lost this ability. The color change from white to yellow takes between 10 and 25 days, the reverse about six days. The yellow pigments have been identified as kynurenine and 3-hydroxykynurenine."
One thing's for sure: everybody eats in the pollinator garden.
It was "hit and miss."
The predators hit, and they missed.
Oh sure, they took a chunk out of these Western tiger swallowtails, but as they say, "a miss is as good as a mile."
The predators? Could have been a hungry bird, praying mantis, or a spider.
The Western tiger swallowtail, Papilio rutulus, a showpiece throughout western North America, populates urban parks and gardens. In color, it's a striking yellow and black, with spots of blue and orange near its tail. Its magnificent wingspan can measure 3 to 4 inches.
If you like to take images of butterflies, don't pass up the Western tiger swallowtail that's missing a chunk here and there. They don't have to be "picture perfect" to photograph--or to enjoy one of the wonders of nature.
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.
Henrietta, our Stagmomantis limbata praying mantis, perches on a Mexican sunflower (Tithonia).
She is as patient as she is persistent.
The drone fly, aka syrphid and also known as a hover fly or flower fly, makes the fatal mistake of touching down on the same blossom.
Henrietta eyes it hungrily. Faster than a blink of the eye, she snares it, clutching it between her spiked forelegs.
"Well, of course, I like drone flies," she appears to be saying, between mouthfuls. "Thank you for asking."
Praying mantids are not known for their table manners. It's grab, hold and eat.
The cycle of life in the garden.
You're heard these idioms:
- The early bird gets the worm
- First come, first served.
- The second mouse gets the cheese.
But have you ever seen a Gulf Fritillary (Agraulis vanillae) eclose and then see her...well...engaged?
Such was the case on Labor Day, Sept. 3 in our little pollinator garden in Vacaville, Calif.
The female (we'll call her "Bride-to-Be") finishes eclosing and is hanging from her empty chrysalis, just drying her wings on the passionflower vine (aptly named) and getting acquainted with her new life stage and leafy surroundings.
Then, whoosh. A suitor (we'll call him "Groom-to-Be") appears out of nowhere. Well, from somewhere, but somewhere quite threatening. He looks tired and worn out, too fragile to fly. (As a colleague said: "He's accumulated a lot of frequent flier miles.") His ragged wings indicate a recent encounter with one or more predators, maybe a bird or a praying mantis. But he lucked out in the Predator-Prey tally: the final score, Butterfly, 1: Predator 0.
He lucks out again. He's the first to arrive at the altar. Our camera catches the action.
"In some Heliconius, the males locate female pupae and may even copulate with the female before she ecloses!" commented butterfly guru Art Shapiro, UC Davis distinguished professor of evolution and ecology. "They are related."
Labor Day, 2018.