THE VIRGINIAN-PILOT
Copyright (c) 1995, Landmark Communications, Inc.
DATE: Wednesday, September 6, 1995 TAG: 9509020212
SECTION: VIRGINIA BEACH BEACON PAGE: 02 EDITION: FINAL
TYPE: Coastal Journal
SOURCE: Mary Reid Barrow
LENGTH: Medium: 99 lines
I have a friend in the yard that has become as familiar a part of the garden as the box turtle that dines on my cocktail tomatoes each day.
Every morning and every evening when I contemplate the zinnias and look at the moonflowers closing or opening, the colorful yellow and black garden spider is there. She sits in her web in the corner of the garden patiently waiting for an unwary insect to fly into her elaborate web and become entangled in the silken threads.
Even if you don't like spiders, they're good to have in the garden because they keep the insect population down.
This one's every bit of an inch or more in size and situates her small grayish head downward, so her large colorful abdomen is highly visible.
Four tiny, creamy white spots stand out on the velvety black swathe down her back and bright yellow and black stripes line her sides. Lithe orange and black legs are poised ready to pounce when the web shakes with the entrance of an intruder.
She has built her home between the stem of a tomato plant grown out of control and a kiwi branch that climbs a trellis on the house. The web is in a fairly protected spot so when I unwittingly plucked a tomato from the vine that held her web, the web vibrated.
Ever alert, she was sure the vibration meant the evening's dinner was taken care of. She moved faster than my eye could see, turning herself completely around in the web, only to find that nothing had flown into her trap. In my younger days, I recall tossing a fly or other insect into a garden spider's web just to watch that instantaneous reaction.
Recently an unwary honey bee was the unlucky meal for the day. When I saw it, the bee had been wrapped round and round with threads, so many threads so close together that the gossamer filament looked like white cotton on a spool.
The hapless bee was secured tightly to an outer quadrant of her web. And the next morning it had disappeared, probably having served as more meal than even a hungry garden spider could consume.
Day in and day out, other tinier insects are always enmeshed in the web, too. But they just hang from the threads as if the spider thought the little bugs were too small to bother with wrapping up and securing.
The big web is spun on support threads that radiate from the center. Several hundred species of North American spiders, including our common garden spider, are characterized as orb weavers because of this circular design. If you look under orb weavers in the field guide, you'll find the garden spider under the name, black and yellow Argiope.
Many orb weavers including my garden resident weave a very thick, distinct zig-zag down the center of their web. It looks exactly like the zig-zag stitch done by a sewing machine with white thread.
The Peterson Field Guide to Eastern Forests questions why a spider would spend the time weaving such an elaborate pattern. The work it takes to come up with such a design obviously uses a lot of of the spider's energy especially when the pattern serves to warn the spider's insect meals of a trap ahead in their flight path.
The authors go on to speculate that the zig-zag may be a useful adaptation. They reason that the visible center portion warns birds and mammals of the web's presence and the animals avoid it, thus saving the spider the energy of repairing her web. The outer strands of almost clear filaments still stand as a trap for flying insects which wouldn't have the broad field of vision that larger animals have.
I refer to the spider as ``she'' because she is easily distinguished as a female by her size. Typically a male garden spider grows to only between 1/4 and 3/8 of an inch in size and is much smaller than the female who is more than an inch long. Although I haven't found it yet, there should be a smaller male suitor lurking nearby before too long.
He builds a similar smaller web on an outlying portion of the female's big home and waits until somehow he knows it's the right time to approach her and mate. After she lays her eggs in a brown papery egg sac, attached to her web, she will die.
If all goes well, her spiderlings will hatch this fall and spend the winter in their protective sac before going their separate ways next spring. And come late summer when they've grown up, there's sure to be another resident spider in my garden.
P.S. GO ON AN OCEAN COLLECTION trip with the Virginia Marine Science Museum at 4:30 p.m. Sunday, leaving from the Virginia Beach Fishing Center. Sea creatures, like seastars, crabs and fish, are hauled aboard the boat and displayed in temporary aquariums. The fee is $10 for adults and $8 for children, 11 and under. Call 437-6003 for reservations. MEMO: What unusual nature have you seen this week? And what do you know about
Tidewater traditions and lore? Call me on INFOLINE, 640-5555. Enter
category 2290. Or, send a computer message to my Internet address:
mbarrow(AT)infi.net.
ILLUSTRATION: This garden spider - a black and yellow Argiope - is
characterized as an orb weaver because of the circular design of its
web. The distinct zig-zag in the center is thought to warn away
birds and mammals, thus keeping them from damaging the web.
Photo by
MARY REID BARROW
by CNB