Orb Weaver Spiders

Orb Weaver Spiders

Spiders are a very important part of our ecosystem.  They play a vital role in eating insects.  One type of spider we wanted to highlight were the orb weaver spiders.  They have a number of interesting characteristics and there could be some in your landscape right now.  Read on to learn more about them.

Webs

Orb weaver spiders make webs with a circular pattern – that’s where they get their name.  If you think of the classic spider web, that’s what an orb weaver web looks like.  There are other kinds of spiders that make circular webs, but these webs help define orb weavers.

Orb weaver webs are generally found outdoors and can be up to 3 feet across.  Their webs are flat, made of spider silk, with sticky and non-sticky parts, and the spiders can adjust how they build them based on local conditions.  Orb weaver spiders can be found in gardens, forests, and in other locations outdoors around the world.

Some webs of orb weavers have something called a stabilimentum.  It is a zig-zag pattern of silk that may reflect ultraviolet light in such a way as to attract insects, deter birds, or both.  It might also be used by the spider to be less noticeable as it hides on its web.

The spiders use their webs to catch prey, although some adult male orb weaver spiders don’t make webs.  Instead, these male spiders stay around the webs of female orb weavers and eat the prey that the females catch.

Some orb weaver spiders build a brand new web every day while others keep the same web and repair it daily.

Oddly, there are some species of orb weavers that don’t make webs.  They instead catch prey in a different way.  One species of orb weaver that does this is the bolas spider.

Appearance

Orb weaver spiders can be hard to identify because the various species look very different.  There are lots of sizes, shapes, and colors.

Generally, orb weaver spiders have eight eyes and have eight legs that can have spines or hairs on them.  They have three toes on their legs so they can walk on the parts of their webs that aren’t sticky.  They have no antennae.

Orb weavers generally can be around one and a half to three centimeters across not counting their legs.  In some species, the females are much larger than the males.

Species

There are over 2,800 species in the family group orb weaver spiders belong to.  Of that, more than a hundred can be found in North America.  The family they belong to is number three in size of spider families (Salticidae and Linyphiidae are numbers one and two respectively).  Some species of orb weaver include the garden orb weaver, the spiny orb weaver, and the yellow garden spider.  Orb weaver spiders can live one to two years.

One type of orb weaver that can be found in Texas is the Golden Orb Weaver.  Females of the species can get up to around two inches in size, not counting the length of their legs.  The males are very small and the females can be up to 50 times larger.  Their webs can be around 3 feet across and their silk has a golden color.  The female has legs with yellow bands and yellow spots on their backs and are grayish brown in color.  They can be found in Texas, Florida, and Central America and can live for about 12 months.

Behavior

Generally, orb weaver spiders might be more noticeable late in the summer through the fall.  They may be more active in the evening and can be nocturnal.  Generally, they aren’t aggressive.

Some types of female orb weavers eat their mates after mating.  The females can lay hundreds of eggs.

They can be beneficial to humans in gardens because they eat insects.

They can be eaten by birds and wasps among other things.  Wasps can catch them by pretending to be prey caught in their webs.

Interesting facts

Did you know that spiders aren’t insects?  It’s true.  Spiders are arachnids.

Also, have you heard about the gold-colored cape made from the silk of golden orb weaver spiders from Madagascar?  It’s worth learning about.

Lastly, did you know that the spider from Charlotte’s Web was an orb weaver?  She was a barn spider and was an orb weaver.