Detective Gluck

What’s This In My Yard?

Have you ever gone outside your house and come across one of these amazing spiders? Have you ever wondered why God made spiders? After all, many people are scared of these creatures!

These spiders are our friends. They help control the insects in our gardens and around our houses. They specialize in flying insects. They also are fun to watch and feed. They have many interesting habits that make them a favorite of many people.

Many Common Names

These spiders are known by many common names. Some people call them black and yellow garden spiders while others call them banana spiders,  corn spiders, and writing spiders. Why so many names, you might ask? Well, people have a tendency to name things for what they observe the spiders doing. These spiders seem to “write” in their webs. Though not words, like in the movie Charlotte’s Web, The designs do suggest writing. Sometimes you will find the letter X , other times just a long zigzag line down the middle of the web. Those that make the X shape are often called St. Andrew’s Spiders. One way to name these spiders with a name used all over the world is their scientific name: Argiope aurantia. This Latin name means “orange spider“, as they often have an orange tint with the yellow and black. Sometimes they even appear silvery when the sun reflects off their hairy bodies.

Zip It Up

If you look closely you can see a zipper shaped pattern down through the middle of their web. There are many ideas about its purpose but it seems that it helps prevent larger creatures from running into the net-like web. It also reflects ultra-violet light that is visible to insects. Some scientists believe it attracts insects into the web.

Good Vibrations

One interesting behavior you might experience with these spiders is when you approach their webs. They have a tendency to vibrate their webs by swinging up and down in the middle. This apparently startles some predators and makes the spiders appear even bigger than they are….And they  are big for spiders!  If the vibrations don’t scare off their enemies they have a habit of dropping off the web and running into a leaf nearby. They sometimes hide in these places until a hapless insect gets caught in the net, but usually they sit right in the middle of the web, head down, ready to run and wrap up any insect that get caught in the web. When an insect hits the web it send signals through the web to the waiting spider. It runs out and shoots out webbing on the victim. It then rolls it up into a package to secure it and immobilize it from fighting back. Sometimes the spider is ready for a meal immediately and it sinks its fangs through the package and starts sucking out the juice from the insect that has been liquified by the poison injected into it. The poison also affects the nervous system of the insect putting it to sleep. Other times the spider keeps its meal for later to consume at its leisure. Once the insect is drained of its nutrients the spider cuts the insect loose to fall to the ground to be recycled in the soil or eaten further by other creatures.

 

Not Harmful to Man

 

Though these spiders are poisonous to insects, they pose little danger to man. I have often held them in my hand without being bitten.  Some people do have allergic reactions to insects and spider bites, but these spiders have rarely caused any concern. I recommend that you watch them without trying to hold them in your hand. It’s good for the spider and allows you to see their unusual behaviors.

Circular Reasoning:  Orb Webs

One of the most amazing things about spiders is their web making abilities. They have several tiny spinnerets on their abdomens that shoot out various types of webbing. Some of it is sticky and some is not. This type of spider is called an Orb Weaver. It makes a circular or oval shaped web. Orb weavers actually have an extra third toe on their feet for handling the webbing. They create beautiful designs with the protein based substance ejected from their spinnerets.  They have special webbing to make their egg cases as well.

Egg Sac

This picture was taken by my friend, Heather Davis. Thank you.

 

The Night Shift

One thing that amazes me is how they redo their webs every night. Did you know they recycle the webbing by eating it and then reusing the protein in future webs. Webbing is very important to spiders. The patterns they make are a testimony of their God given talent for making designs that are not only beautiful but very functional. Most of their web building takes place at night after a day of sitting and waiting for prey. They are born with this ability and need not learn how to make a web. God equipped them so they would be ready right from the get-go! If you think this is a simple task, just try making a web from string. It is a difficult task and it won’t function as well as the spider’s web.

Watch for Tiny Males

One thing that is harder to see is the tiny male spiders. They often build smaller webs near the female’s large web. After mating with the females they quickly die off. Their primary purpose is providing sperm for the females to fertilize their eggs.

 

How Many Babies in One Egg Case?

Talk about having all your eggs in one basket! The female creates a brown papery egg case that is full of eggs. 400 to up to 1400 eggs are found in one egg case! These egg cases are about 1 inch in diameter. The females can create two or three of these egg cases which hold their young. The babies hatch out in the fall and remain inside the egg case until the springtime. “Why so many?” You might ask. Only a few of the spiderlings will make it to maturity. They are eaten by other spiders and other creatures when young. By having so many young, the spiders can insure that some will survive to carry on the species.

Do You Want to See Them in Action?

One of the funnest things to do is to feed the spiders and watch what they do. Catch small insects and toss them into the web. Sometimes they will pass right through without hitting a strand of webbing, but when they do, you will see a lot of action. The spider will quickly feel the vibration of the struggling insect and run out to subdue it. I like to catch grasshoppers and crickets to feed them but they also love flies, moths, butterflies and other insects. If you find a large spider you can feed it several times a day.

 

Don’t Be Afraid of Me!

Though I might look scary to some, I really am your friend. I help keep the bugs in your yard under control and love to provide entertainment for a meal.