The busy arachnid outside your window is doing good work
This, Oh, Best Beloved, is my favorite time of year—our back yards are full of Charlottes, aka the orb weaver spider. If truth be known, we could not get along as well as we do on this beautiful Old Earth, without all the Charlottes and her relatives that build their silken orbs on our porches, backyards, barns, chicken houses and shrubs.
If you have ever taken the time to inspect Charlotte's Web, you will discover one does not have to read E. B. White's beautiful book to see she eats hundreds and hundreds of harmful insects—flies, moths and wasps in particular.
The huge, thumb-sized female spiders weaved their foot-in-diameter webs right between the raspberry vines on the farm where I lived in Connecticut as a young lad. My grandfather would send me out to pick berries when I was about eight years old, just the right height for me to run into those gorgeous spiders, right smack dab in the face.
I ended up with the most horrendous case of arachnophobia. When I was sent to pick berries, I often got sick to my stomach and threw up. But one day, as was his way, my beloved grandfather sat me down to talk common sense about spiders.
He convinced me to stop and look at what those beautiful spiders were eating. Flies and moths, with an occasional beetle, butterfly or wasp, were among most of her victims. He also convinced me that if I continued with my attitude about spiders, I was going to have a tough time getting through life. Spiders, like it or not, are in every place on earth. It worked—more than he knew. In the 70s, I went to Australia to study spiders, and let me tell you, they have some fair dinkum beauties.
The other night I happened to be closing the door after the house cooled down, and there, in all her glory, was Miss Charlotte building a snare right next to the back door. We've been walking through her tiny web supports all summer, but she was so small she was hard to find in daylight. The one I spotted in the photo above is a teen-ager, about the size of my little fingernail.
Orb weavers, in spite of their size, are no threat to man and pets. Their venom is designed to kill insects and prepare them to be devoured. Spiders do not posses jaws and teeth for chewing. Another role of their venom is to pre-digest what they've caught, which is then sucked into the spider's stomach.
With that in mind, let me share a few thoughts about orb weavers: Most barn spiders are nocturnal, and most females have a yellow and/or brown horned abdomen, black and white striped legs, and a marking on the dorsal side. The color of the abdomen ranges in hue and shape. The females are about three-quarters of an inch long with large round abdomens, while the males are tiny wimps, compared to females.
Many species of orb weavers (and there are thousands of them) take down the web in the morning and rebuild it every evening, thereby conserving silk and body energy by recycling. To keep out of harm's way during the day, they hide under the eaves and leaves. At night the spider will "sit" (if that's a correct term) in the middle of the web and wait for an insect to land on the sticky part, wrap it up as quickly as possible, inject a good shot of venom and then go back to her perch and wait for another hapless victim.
Barn spiders are typically a North American breed, but in addition to speaking English, they're also glib in Spanish and French. All told there are more than 10,000 species, making up more than 25 percent of the entire spider group.
If you want to do something diabolical, slowly come up to Charlotte in her web and blow gently on her. Way back in her primordial brain an alarm goes off, "Alert, alert! Enemy incoming!" and she'll begin to bounce in the orb. Apparently this works to keep her from being eaten. Perhaps such behavior makes her look bigger, but it also triggers another reaction, "Food!" Bouncing the sticky web helps wrap her victim more quickly.
If bouncing doesn't work, she'll take hold of the snare and shake it in an attempt to capture what may have stumbled into it in the dark, which often works to entrap a moth, fly or even an adult flying ant lion. There is a big orb weaver with a web attached to the rear of my bee hive that captures wax moths and hive beetles, but no bees, as she takes her web down at night.
Male orb weavers are about a tenth the size of the females. As it is with spiders, he must exercise the utmost caution when entering her web with mating on his mind. When the female is ready to mate, she puts off a subtle scent that the male senses with the "hairs" (setae) on his first pair of legs.
He enters the very outside part of the orb and plucks the first line, gently. Spiders are capable of making sounds, so I suppose he whispers, "Yoo-hoo, here I am...!" If all goes well and he can get close enough without being gobbled up, he will take a position directly under her abdomen and transfer his sperm with his large boxing glove-like pedipalps. And if you don't think that takes daring, her epigynum is only a whisper away from her fangs... It's gotta be, "Wham, bam, thank you ma'am."
Soon after, she will wander away from her beautiful silken orb for the last time, find a safe place out of the weather, hidden from spider-eaters, and lay her eggs in a soft, golden bag about the size of the first joint of your middle finger. Then, as all of us will do at sometime, she will die, but leave her mortal remains covering the egg sack. When her babies hatch she will be their first meal, and then they will climb up onto a high perch, let out wisps of gossamer silk that will act like a parachute and fly away to new places—where they'll eat moths and flies, and save pigs named Wilbur.
Photo taken by Jim Anderson.