Posts Tagged: spider
“The brown widow is spreading like wildfire,” said UC Riverside urban entomologist Rick Vetter. "It’s a very prolific pest. People find them by the hundreds in places where they haven’t seen spiders before.”'
The brown widow poses less of a health threat than black widows, but Vetter said there are several reasons why the agricultural community should be concerned about their potential northward migration. Currently little is known about brown widow spider biological control. While black widows prefer low hangouts, it is not yet known whether brown widows will adjust to higher posts in California. If the spiders take up residence in fruit orchards, for example, they could pose a problem for farmworkers.
“Pickers and harvesters won’t want to have these spiders falling down on them,” Vetter said.
Brown widows could also potentially congregate in agricultural shipping containers or packaging.
Brown widow spiders are native to Africa and are established in tropical environments throughout the world. They have been found in Florida for many decades, but only recently expanded their range from Texas through South Carolina, and into Southern California. As of 2009, the spider was established in Los Angeles, Orange and San Diego counties, and in 2010 it made its way to Riverside, San Bernardino, Ventura and Santa Barbara counties. There have been a few finds in areas further north.
“I’ve gotten three females from Sacramento and three females from Washington (state),” Vetter said. “I’ve gotten no other spiders from those areas, so I don’t know if they will be another infestation area or not.”
Vetter is asking the public to assist in his brown widow spider research by carefully following instructions for collecting and sending brown widow spider specimens to the university. Potential spider collectors should study the photos on his website to learn the characteristics of brown widows. Because the spider is already established in Southern California, Vetter does not need specimens from San Diego, Orange, Los Angeles and the Riverside and San Bernardino-Redlands area. More specimens are welcome from Ventura, Santa Barbara, from Riverside and San Bernardino counties outside of the urban cities in the western part of the counties and from all the rest of California.
For spider shipping instructions, see Vetter’s brown widow spider research page.
Watch an 80-second video for tips on identifying brown widow spiders:
The very presence of a black widow spider, shiny black with a globe-shaped abdomen, strikes fear in most people.
And not just on Halloween.
"Many spiders will bite when trapped but black widow spiders (Theridiidae: Latrodectus) are the most dangerous North American species," write Charley Eiseman and Noah Charney in their newly published book, Tracks and Sign of Insects and Other Invertebrates: A Guide to North American Species.
"Their strong venom can kill," agrees George C. McGavin in the Smithsonian Handbooks' Insects, Spiders and Other Terrestrial Arthropods, "but a fast-acting antivenom can be given by injection."
The black widow is a cobweb spider and "the females produce about 200 to 250 eggs, attached to the web in a sac," McGavin says.
So, where can you find black widow spiders? They're usually in more concealed places than the common house spider, which is "found in any dry structure, including houses, basements an barns, as well as under natural 'roofs' such as overhanging ledges," according to Eiseman and Charney.
And, Eiseman and Charney point out, the black widow spider webs are "composed of extremely strong, coarse threads"--unlike those of common house spiders.
McGavin says black widow spiders are commonly found in leaf litter, under stones and in and around buildings.
We sighted one under leaf litter recently at the Harry H. Laidlaw Jr. Honey Bee Research Facility at UC Davis. Its distinguishing mark: the reddish-orange hourglass on its stomach.
Then last week we spotted a black widow spider guarding her gumdrop-sized sac in a secluded area of a UC Davis parking garage.
She didn't pay attention to the "permit parking only" signs.
Black Widow Spider
She didn't come home last night.
The little honey bee at the Harry H. Laidlaw Jr. Honey Bee Research Facility, University of California, Davis, wound up in a spider's stomach.
This morning we stopped by the Häagen-Dazs Honey Bee Haven, the half-acre bee friendly garden planted last fall next to the facility, and a spider was having breakfast--one of Susan Cobey's New World Carniolans.
We spotted the same spider chowing down on a ladybug during the grand opening celebration on Saturday, Sept. 11, and we remember saying "Good, it didn't get a bee."
This time it did.
I jokingly asked beekeeper Elizabeth Frost, staff resource associate who works with Cobey at the Laidlaw facility, if she were missing any bees. (After all there are "only" about six million of them in the apiary.)
It would have been hilarious if she had said "Did a bed check. One unaccounted for."
Bee and the Spider
Bank robbers rob banks because that's where the money is.
Spiders lurk in flowers because that's where the insects are. Whether they spin a sticky web, ambush their prey or just outrun or outmaneuver insects, spiders are there.
This morning a spider successfully trapped a honey bee in what amounted to an intricate "world wide web" connecting a tower of jewels (Echium wildpretii) to catmint (Nepeta).
But just as the hungry predator began racing toward its struggling prey, something unexpected happened.
Freedom. The photographer flicked the web and released the bee.
Just in time for National Pollinator Week.
A spider web is nature's lace, a symmetrical work of wonder.
Well, a sticky, deadly trap if you're an insect. Then you become just another tasty morsel for the predacious, albeit artistic, spider.
Watching an orb weaver or garden spider maneuver a web is like watching a circus acrobat glide from one silken rope to another.
The finished product--a combination of delicacy and strength--looks like the needle lace doily that your great-grandmother crafted for her parlor chairs.
Sure, some folks hate spiders and every time they see one, they gasp in horror or harbor thoughts of spidercide.
Me, when I see one, I spray a little water to highlight the art. Then I grab the camera.
Fact is, you should welcome garden spiders into your garden and let them "put a spin on it." These little arachnids will snare such insects as flies, gnats and mosquitoes.
Charlotte, where are you?