Why are there so many spider webs in the fall?

Question Why are there so many spider webs in the fall?

Answer It takes most of the summer for some spiders to grow up. When spiders mature, they lay eggs. In order to have energy to produce eggs, they have to eat. They eat by catching insects in their webs. Therefore, spider webs are prevalent in the fall.

While similar, spiders are not insects. Instead of six legs, spiders have eight. They belong to the class Arachnida, named after Arachne, a maiden in Greek mythology. According to myth, Princess Arachne challenged the goddess Athene to a weaving contest. When Arachne lost, she was turned into a spider and destined to weave forever.

The most common fall spiders are called orb weavers. There are several families of spiders in this category. These spiders create orb (circular) shaped webs. These webs are usually spun just before sunset. Nocturnal insects are caught in the webs.

To make the webs, spiders produce silk from glands called spinnerets. Orb weavers can have three or four pairs of these glands, each producing different textures of silk (non-stick silk for the radial web lines, and sticky silk for the spiraling strands). Spider silk is a protein that hardens as it is stretched from the spinnerets. It may appear fragile, but it is unbelievably tough. The relative tension necessary to break it is far greater than for steel.

The largest and most colorful orb weaver in this area is the Golden Garden Spider or Writing Spider (Argiope aurantia). The best known writing spider was named Charlotte. Charlotte's Web is a story about writing spiders (orb weavers). They grow up, build a web, write a few names, lay some eggs and check out (die).

Orb weavers are reluctant to bite people. Symptoms are usually negligible such as mild local pain, numbness and swelling. Occasionally, nausea and dizziness can occur after a bite. Obviously, you need to go to a doctor if you feel ill. The old saying about a person dying if a writing spider spells your name in her web is not true. They can't really write.

Poisonous spiders, like the black widow and brown recluse, do not make orb shaped webs. They make cobwebs (irregularly shaped webs). Cobweb spiders are usually found in the house, in a barn, under equipment, in a wood pile, etc... Clean the cobwebs out, but leave the orb webs.

Spiders found in the house are usually not the same species as the garden spiders. Most indoor spiders belong to a small number of species specially adapted for indoor conditions (constant climate, poor food supply, very poor water supply). Some house spider species have been living indoors at least since the days of the Roman Empire, and are seldom found outside.

Garden spiders usually spin a new web every night. Fog or heavy dew makes these webs more visible in the mornings. Take the time to admire the orb webs in the fall. They are splendid examples of nature's engineering and beauty. They are also the final chapter in the life of the Golden Garden spider. Everybody cries with the little pig when Charlotte dies.

For orb weaver info, visit http://www.uky.edu/Ag/CritterFiles/casefile/spiders/orbweavers/orb.htm If you do not have internet access, then call me at 910-893-7533 or email me at gpierce@harnett.org

When you see those big webs, don't tear them down. Give a single mom with hundreds of babies a break. She's only trying to catch those bugs that you're trying to keep out of the house.

Gary L. Pierce

Horticulture Extension Agent

Harnett County