We arrived home from a ten-day trip to an invasion of grasshoppers. With each step we took, a cloud of grasshoppers fled before us. They were even munching on a window screen!
One morning I noticed a big yellow and black garden spider had spun a web that reached from the top of the window with the grasshopper-eaten screen to the forsythia bush below the window.
I must get the broom to sweep that spider web down, I thought.
That spider is one of forty to sixty thousand species that make up the arachnid class, along with scorpions, mites, and ticks. Although a square yard of grass may contain 500 spiders, I didn’t like this one having her home outside my kitchen window.
Like other spiders the world over, this one had no skeleton. An insect has three body parts: head, thorax, and abdomen, while a spider has two body parts. Instead of a head and thorax, a spider has one part called the prosoma.
A spider’s other body part is called the opisthosoma. Spiders have eight legs growing from the prosoma, while insects have six legs.
As we sat at the dinner table, the spider sat motionless on her web, waiting for an unsuspecting insect to fly into it. Rather than hunting prey, most spiders spin webs in places where their prey will accidentally encounter them. When the oven timer sounded, I stood up to take the cake from the oven just as a grasshopper jumped into the spider’s web!
In spite of her eight eyes, the spider has poor eyesight, mostly just seeing light and dark. Because of her poor eyesight, the spider didn’t see the grasshopper, but she felt the web vibrate.
The more the grasshopper kicked, the more entangled he became in the sticky web. On nimble feet the spider started toward the hapless grasshopper.
I picked up a pot holder and opened the oven door. Bending over, I took the cake pan from the oven and turned the oven off. I glanced out the window and gasped in surprise. I had a partner in my fight against grasshoppers! The spider could stay, though I am not a great fan of spiders!
In the length of time it took me to remove the cake from the oven, the spider had injected the grasshopper with poison from her fangs and completely wrapped it in a cocoon of silk produced by spinnerets on her opisthosoma. The poison would liquefy the grasshopper so that the spider could suck it from the cocoon.
Besides using the silk to spin webs and bind prey, spiders also use silk as a safety line when climbing. Some young spiders go “ballooning” to find a home. This practice consists of climbing to the top of a plant or other object and spinning a strand of silk which is caught by the wind. They may travel through the air for many miles before landing at their new home.
Silk leaves the spinnerets as liquid. As it stretches, it solidifies into thread. A spider’s silk is stronger than the same thickness of steel wire. Some spiders wrap their eggs in a protective silk cocoon and carry their egg balls on their backs.
Scientists are exploring possibilities for using spider silk. Some possibilities are in Kevlar® vests. Another possibility is to make wire.
Spiders are among the most important predators of insects, though their efforts are often under-appreciated by people, including me! Watching “our” helpful spider entertained us as we sat at the kitchen table. A severe thunderstorm damaged her web, but she repaired it.
God created spiders in lots of colors and sizes. Some spiders use camouflage for protection and for catching unsuspecting prey. Their dull colors and stillness help trap unwary insects in their webs. Some of the crab spiders change colors to match the white or yellow flower they are in. This makes it easier for them to catch unsuspecting insects.
As we watched “our” spider, we noticed that she was larger sometimes than at other times. She grew plump when plenty of grasshoppers jumped into the web. Other times she was thin, as though she were on a diet. Her size depended on how many insects blundered into her web!
Tarantulas, the largest spiders in the United States, are found mostly in warmer regions like the southwestern deserts. Their hairy bodies can be over 5 inches (13 cm) long. Tarantulas pounce on their prey and inject it with poison.
Tarantulas have a longer life span than other spiders. Females may live up to twenty years. Tarantulas can survive extremely unfavorable conditions. They can live several years without food and several months without water.
Black widow spiders live in many habitats from southern Canada to the top of South America. Southern black widow spiders are black with a red hourglass under the opisthosoma, while the northern black widows have a row of red spots on top of the opisthosoma with two crosswise red bands underneath.
Black widow spiders are not aggressive and seldom bite unless they are accidentally squeezed in the folds of clothing or shoes; then they bite in self-defense. Some people are hardly affected by the bite while others may have a severe response. Their powerful neurotoxic venom causes a sharp pain at the site of the bite within half an hour. The pain may be followed by abdominal pain, muscle cramps, weakness, and tremors as the poison affects the nerves. Their bites are rarely fatal, but if you suspect you have been bitten by a black widow, call a doctor. An antivenin is available, and pain medication may be needed.
Brown recluse spiders are a medium-sized spider living from eastern Texas to western Georgia and north to southern Illinois. Brown recluse spiders are marked by a fiddle shape on the prosoma just behind the eyes. As their name “recluse” suggests, these spiders retreat when possible and prefer dark, undisturbed places at or near the ground for their webs. It is usually when they have taken refuge in clothing or bedding that people are bitten. Their painful bite, which is rarely fatal, can cause a sore that is slow to heal. If you are bitten, call a doctor.
Many people harbor unnecessary fear of spiders, which is called arachnophobia. Perhaps people fear spiders because of their silence; they seem to appear from nowhere. Or people may fear spiders because some are poisonous. Most North American spiders, however, are not. Spiders are shy animals that run from danger when possible, and they bite only in self-defense.
