And God Created … An Amazing Orb-Weaver Spider

David Everson

When God created the spiders, He created an amazing group of living things. They have tremendous variety of life styles from web builders to ground dwellers who spin very little if any web. There are over 35,000 known species of spiders with estimates of thousands more that are as yet undiscovered. Each one of them could be looked at closely, and we could marvel at the wonders of the mind of the creator for being able to construct such creatures who so well fit their role in the world. While not many people are fond of spiders, spiders do deserve our respect and awe as we look at the design features they were given by God. In this article, I would like to look at one particular species of the orb-weaving spider. God designed it with the ability to make a decoy of itself to fool predatory wasps from having it as an easy meal!

The orb-weaver spiders (family Araneidae) are the builders of the spiral wheel-shaped webs we find in gardens, fields, and forests. Their common name is taken from the round shape of this typical web. Generally, orb-weaving spiders are three-clawed builders of flat webs made with sticky spiral capture silk. The building of a web is an engineering feat by itself. It is begun when the spider floats a line on the wind from one surface to another. The spider secures the line and then drops another line from the center, making a “Y.” The rest of the scaffolding follows with many strands of non-sticky silk being built before a final spiral of sticky capture silk is placed in the web to capture prey. Many of these webs are spun daily with the old one being eaten before the next one is built! However, just building a very intricate web is not the only thing that one of the orb weaver spiders does; it makes a life-sized decoy of itself in the web!

While studying orb-web spiders in Taiwan, two researchers from Tunghai University were amazed by the way strange looking ornaments were used and found in many of these spiders’ webs. Upon closer inspection, they observed that each of these decorations was the same size as the spider that produced it. The coloration and shape of the ornament were very similar to that of the individual spiders in that web. This was the first discovered case of a living animal’s (other than human) producing life-sized replicas of its own body.

After further video taped observations of the spider’s daily life, it was discovered that the spider was making and placing these replicas as a decoy against its enemy, a spider-eating wasp. Most webs would have at least one of these decoys and, in some cases, two or more “look-a-likes” in the web. When a wasp was attracted to the web, it had a higher than average chance of “finding” a decoy rather than finding the “real thing.” These decoys are made with what is called “prey pellets and egg sacs” which they make or the left-overs of an earlier meal, that were the same size as the web building spider’s body. It became apparent that the wasps were attracted to the “decoys” as often as to the real thing. To the wasp, the decoys must look like the spider. When the wasp attacks a decoy, the real orb-web spider then is alerted to the presence of the wasp, and it finds a hiding place out of the web to wait till the predator leaves.

This increase in the number of “apparent meals” in the web on the part of the spider was actually found to attract the attention of the wasps to the web, but the increased number of “targets” for the wasp to attack decreased the likelihood that the spider would be killed.

This is the first time that scientists have discovered the use of “animal-made decoys” and reveals the complexity of behaviors that God created in these animals and should cause us to stop and “be still and know that I am God!” Psalm 46:10. –Rt 1 Box 116A, Belington, WV 26250.

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