Posts Tagged: Honey bee
Ophthalmologist and professor Ivan Schwab of the UC Davis Health System says that spiders “get a bad rap. Few would harm you, and only rarely are spiders aggressive towards humans. Most will defend themselves if threatened, of course, and a few are venomous. Most spiders, however, would prefer to ignore humans and be ignored by us.”
At his UC Davis Department of Entomology and Nematology seminar on Oct. 23 in Briggs Hall, Dr. Schwab told the crowd that jumping spiders have the “best acuity of all spiders.” They are ambush spiders, lying in wait for prey.
If you visit your garden or a neighborhood park, you may see a jumping spider looking back at you. Last Sunday we spotted a jumping spider lurking beneath the petals of a yellow rose. Meanwhile, a honey bee foraged above it.
That reminded us of what Dr. Schwab said about spiders and how they see.
Background: Dr. Schwab directs the Cornea and External Disease Service and serves as the medical advisor of the eye bank, as well as professor of ophthalmology in the Department of Ophthalmology and Vision Science. He’s the author of five books, including the highly acclaimed Evolution’s Witness: How Eyes Evolved, published in November 2011. He describes the eye as "evolution's greatest gift and its greatest triumph."
The UC Davis ophthalmologist writes an informative blog, Evolution’s Witness, and recently penned one, with amazing detail, on jumping spiders. “Jumping spiders are positively charming creatures, and you will know that to be true if you have ever watched one closely. These are common spiders and range from approximately 3 to 17 mm in length and will watch you closely as you approach them. They have four pairs of eyes, with the large anterior median (AM) set the most obvious. These circular eyes provide an ‘attentive child’ appearance because they are fixed and are relatively large based on body size, but are tiny on an absolute scale. These placid eyes belie the organized complexity and evolutionary genius that lies beneath the carapace.”
Dr. Schwab goes on to describe the AM eyes as "Galilean telescopes with a corneal lens fixed to the carapace, and a second 'lens' at the end of a small tube immediately in front of the retina."
"This compact telephoto lens system combined with the tiered retina," he says, "achieves excellent acuity, but only a very tiny field of vision. So, to increase this field of acute vision, this optical marvel moves the tube housing the retina with six muscles per eye by mostly scanning movements. This is akin to a raster scan similar to those seen on a TV or computer screen. Jumping spiders scan their world much like painting a wall with a fine brush although the retina is not linear, but shaped more like a boomerang. The other pairs of eyes do not scan and are principally used as motion detectors to find other animals for the AM eyes to decipher."
"With the AM eyes, jumping spiders have the finest discrimination of all arthropods, and probably all invertebrates as they are visual hunters, whereas most other spiders use the tools of silk."
Dr. Schwab marvels at how a jumping spider is able to see so well and ambush its prey. "If the spider moves, it may frighten the prey, so the spider needs another mechanism." Read Dr. Schwab's column for the details on that mechanism. After you do, you'll come away with a greater appreciation of jumping spiders and that most amazing organ, the eye.
By the way, this visual hunter (below) didn't nab the honey bee Sunday afternoon....but it may have later.
Jumping spider peering between the petals of a yellow rose. (Photo by Kathy Keatley Garvey)
Close-up of jumping spider as it emerges from its hiding place. (Photo by Kathy Keatley Garvey)
Side view of jumping spider. (Photo by Kathy Keatley Garvey)
The prey (honey bee) that the predator (jumping spider) was seeking. (Photo by Kathy Keatley Garvey)
Two 'streaks on a sedum.
Sounds like a song, doesn't it?
Make that two 'streaks and a honey bee.
In a way, the butterflies, with their sails up, looked like the America's Cup contestants. Yes, Oracle Team USA streaked by Emirates Team New Zealand by 44 seconds today to win the 34th America's Cup.
Sports enthusiasts called it the greatest comeback in 162 years of competition. The Oracle was down by 8-2 and then won eight consecutive races to win The Cup.
Meanwhile, the gray hairstreaks just kept foraging on the sedum, while the honey bee cast a wary eye.
Two gray hairstreaks and a honey bee sharing a sedum. (Photo by Kathy Keatley Garvey)
Today (Labor Day) began just like any other day.
And it ended just like any other day, except for the Labor Day celebrations that we humans plan.
For Nature's predators and prey that frequent our garden, however, it was an intertwining of life and death.
A western spotted orb weaver, Neoscona oaxacensis, spun a web on our tower of jewels, Echium wildpretii, and snagged, killed and wrapped a honey bee. Using the web as its lifeline, it tugged the bee into the shadows to eat it, undisturbed.
The tower of jewels, in bloom now for five months, looks like a tower of bees when the honey bees, syrphid flies, and carpenter bees share it. The plant is looking a little ragged now--it's going to seed--but it's still producing spectacular reddish-pink blossoms.
The spiders know where to spin their webs. They will be back tomorrow, as will the honey bees.
Western spotted orb weaver snares and wraps a honey bee. (Photo by Kathy Keatley Garvey)
The spider's spots are visible in this photo. (Photo by Kathy Keatley Garvey)
After tugging the honey bee into the tower of jewels, the spider proceeds to eat it. (Photo by Kathy Keatley Garvey)
This honey bee narrowly missed being a target of the spider. It is nectaring on a tower of jewels, Echium wildpretii. (Photo by Kathy Keatley Garvey)
Take one honey bee and one Japanese anemone. Then add one jumping spider.
The results don't always turn out so well.
But today in the East Asian Collection Garden of the UC Davis Arboretum, everything turned out well--for the honey bee.
The bee foraged on the golden stamens of the Japanese anemone without becoming prey, despite the spider camouflage with an anther.
The East Asian Collection Garden is just one of 17 gardens or collections in the 100-acre UC Davis Arboretum.
Located near Mrak Hall, the "East Asian Collection is a popular place for picnics with open lawns and lovely views of Lake Spafford," according to the Arboretum website. "Cherry blossoms and daphne are standouts in winter and spring, while gingko and zelkova trees and ornamental grasses provide beautiful fall color."
Arboretum officials say the plants represent "a living museum."
Indeed they do. The gardens are also a good place for students, staff, faculty, flowers, insects and spiders to interact.
The beauty of the Arboretum defines the UC Davis campus.
Honey bee in flight, heading toward a Japanese anemone and unaware of the spider. (Photo by Kathy Keatley Garvey)
Honey bee forages while the jumping spider lurks. (Photo by Kathy Keatley Garvey)
This was a perfect time for the jumping spider to nail the bee, but it didn't. (Photo by Kathy Keatley Garvey)
Just call it a missed opportunity.
Catmint (genus Nepeta) draws scores of insects, from honey bees to leafcutter bees to European wool carder bees.
It also draws spiders.
We usually see a cellar spider (family Pholcidae) trapping prey in its web. It inflicts a fatal bite and then wraps it for later consumption.
This cellar spider, however, crawled along a catmint stem to wait for prey. A honey bee buzzed down and began nectaring one of the lavender blossoms.
It was not aware of the predator. Just as the spider moved toward it, the bee took off.
Later we saw the cellar spider wrapping prey. A closer look revealed it was not a honey bee, a leafcutter bee or a European wool carder bee.
It was another cellar spider. Sexual cannabalism? Maybe. A very hungry cellar spider inept at catching a bee so it nailed a fellow spider instead? Perhaps.
At any rate, that was "what's for dinner."
A cellar spider eyes a honey bee in the catmint (Nepeta). (Photo by Kathy Keatley Garvey)
All wrapped up--a cellar spider nabs another cellar spider. (Photo by Kathy Keatley Garvey)