- Author: Kathy Keatley Garvey
A pollinator garden is a study in diversity--and of inclusion and exclusion.
The residents, the immigrants, the fly-bys, the crawlers, the wigglers, the jumpers. The big, bad and bugly. The prey and the predators. The vegetarians and carnivores.
The nectar-rich flowers attract honey bees, bumble bees and butterflies. And right near them are the predators: the praying mantids, dragonflies and assassin bugs.
The assassin bugs, family Reduviidae, are ambush predators. They resemble human assassins (or at least those on the movie screen!): long narrow neck, beady eyes, and sturdy body. When they ambush a predator, they stab it with their rostrum, inject venom, and suck out the juices. Or as UC Berkeley entomologists Jerry Powell and Charles Hogue write in their book, California Insects, "The victims, which include all kinds of insects, are snatched by quick movements of the forelegs, and immediately subdued by a powerful venom injected through the beak."
Such was the case with the assassin bug, Zelus renardii, this week. We watched one lie in wait on a Mexican sunflower (Tithonia); we watched another dine on an unidentifiable prey on a milkweed blossom; and we watched yet another stab a lady beetle (aka lady bug) on a leaf.
Everybody eats in the pollinator garden.
- Author: Kathy Keatley Garvey
How magical are the dragonflies.
They zig-zag through the pollinator garden, a perfect portrait of a predator: multifaceted eyes, strong wings, and mouthparts that include a toothed jaw and flap like labrium.
They're an ancient insect: scientists have found fossil dragonflies that date back 325 million years ago.
Bank robber Willie Sutton (1901-1980) reportedly said he robbed banks "because that's where the money is." Predators, like dragonflies, frequent pollinator gardens because that's where the food is--food like native bees and syrphid flies.
Like other dragonflies, red flameskimmers, Libellula saturata, frequent our pollinator garden because of "Sutton's law." We welcome them with bamboo-stake perches. They circle the garden on their hunt, snag prey, and return to the perch to consume it.
Sometimes, if you're lucky, you'll see a dragonfly eat a bee (lucky for a nature photographer who wants to share a little bit of how nature works, but not so much for the bee!).
We can't tell what bee was on this male flameskimmer's menu, but it appears to be a longhorned bee, maybe Melissodes agilis, family Apidae.
It's eat and "bee eaten" in a pollinator garden.
- Author: Kathy Keatley Garvey
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 predator and the prey: Misumena vatia and Apis mellifera.
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."
Who knew?
One thing's for sure: everybody eats in the pollinator garden.
- Author: Kathy Keatley Garvey
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.
- Author: Kathy Keatley Garvey
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.