Naturalist's Corner - Fall Spider Work

Welcome to our new, occasional column that takes a deeper look at the natural world we see around us as we hike. Our guest writer today is Tracey Koenig, purveyor of interesting tidbits. Tracey is a retired nature center director currently living in Wisconsin.  Always interested in the natural world, Tracey shares her nature knowledge to help others understand the natural world around them.

Eensy-Weensy spider - well, not so much in October!

As we begin the wind-down from fall toward winter in the upper Midwest, you may have noticed that there are spider webs and spiders everywhere you look!  They seem to have appeared out of nowhere and they are huge!  So where have they been? 

These spiders have been there all along, but they start out the year as tiny little spiders.  Suddenly, about the middle of August, you find them everywhere.  In this neck of the woods, spider life cycles are usually limited to one summer, so their life cycle is on a deadline! 

The huge spiders you see in webs at this time of year are females.  They are eating and growing in advance of making the egg sacs that will protect the spider eggs through the winter.  Where is Dad all this time?  Look closely in the web for a small spider - that’s Dad.  Some female spiders eat the male right after mating.  

A be-dewed orb weaver web

The two most common spiders we see here in the upper Midwest are the orb weavers and the funnel web spiders.  Orb weavers include the beautiful black and yellow garden spider (Argiope aurantia).  As a kid growing up in Ohio, we always called them “Zipper Spiders”.  Take a look at their web and the reason for the name will become clear.  Every year an industrious Zipper Spider would weave her web across the front door of our house.  My mom would announce that the front door was now off limits, and we should all come and go through the garage. 

Zipper spiders are fun to watch on their webs.  If she senses something nearby that concerns her, she will vibrate the web, so it swings in and out in an attempt to ward off whatever it is that she is worried about.  You can encourage her to vibrate the web if you gently blow on the “zipper”.  You can “feed” her if you capture some insects (taking into consideration the size of the web and spider.  Prey that is too big can destroy the web).  Just toss the insect into the web and stand back. You’ll be treated to a demonstration of how this spider wraps its prey in silk.  There are several species of orb weavers in this area, and all have round “marble-like” bodies and beautiful circular webs.

Funnel Spider web.
Though hard to see in this image,
the funnel descends to the right
above the twist in the lower part of the image

Funnel web spiders are also very common, though their unique web is not often seen.  They will spin a flat web for catching prey and add a funnel at a corner where the spider hides until something in the web needs attention.  You can see sheet-like funnel webs on top of grass, on top of shrubs, and anywhere the combination of flat surface and corners is perfect for web construction.  When you’re out and about, look at corners of structures to find the female waiting for prey.

What happens to the spider over winter?  Yellow garden spiders (and other orb weavers) make one to several egg sacs that survive the winter, but the female dies when her job is complete.  Male funnel web spiders die after they have mated.  The female creates the egg sac and then dies as winter is setting in.  Egg sacs of both species produce young in the spring, and the cycle begins again. 

Images - Marge Loch-Wouters