Each fall it seems that spiders appear from nowhere, crawling along the ground, stretching out their sticky webs across our favorite hiking trails, and even entering our living spaces. The truth is, they’re with us the entire summer, we simply may not notice them because they, along with their webs (if they construct them), are much smaller and less obvious than in fall. Above and below you will see some of those spiders, all of which were found along the paths of the Outdoor Exhibits at the Museum of Life + Science during the first few weeks of October.
The Banded Argiope (ar-GUY-o-pee) Spider above is very similar to the Black and Yellow Argiope Spider, and builds the same type of web. Notice the heavy banding on the abdomen.
The Argiope, Spotted Orbweaver (above), and Marbled Orbweaver (below) are all orb weavers, so named because of the circular webs that they build. The Argiope and Spotted Orbweaver are common and familiar spiders. However, when most folks encounter their first Marbled Orbweaver they are surprised by the spider’s brightly colored, swollen abdomen with its intricate pattern; it certainly made me do a double take the first time I saw one.
Wolf Spiders like the one below are very common. Grassy areas may be littered with wolf spiders, but they often go undetected under the cover of the grass. The one pictured below was seen crossing the path next to the Ornithopter in Catch the Wind.
Caterpillars are another common sight during the fall months. Nearing the end of their larval stage, they are often encountered while crawling off their host plant in search of a place to pupate, spending the winter pupating underground or in the leaf litter.
The two tussock moth caterpillars pictured above and below are two species of tussock moth that I’ve most frequently encountered on the paths of the Museum’s Outdoor Exhibit Area. I’ve handled both of these species before and have had no problems, but I’d advise you to NOT handle them if you see them crawling along as you stroll the paths of the Outdoor Exhibits; the hairs on these caterpillars have been known to cause an allergic reaction in some people.
There’s no shortage of Smartweed in Explore the Wild, Catch the Wind, or on the Dinosaur Trail, so it’s little wonder that there’d be a Smartweed Caterpillar somewhere along the paths that wind through these areas. The two images below show the same individual seen at the U-shaped pond alongside the Ornithopter.
While attending the Ornithopter, Ranger Katie spotted a fairly large caterpillar crawling along on the Orhnithopter itself. We later determined that it was a Snowberry Clearwing. By its rapid and determined pace, it was obviously heading off to pupate. I managed to get a few images of the larva before sending it on its way. One of those images can be seen below.
On September 3o, I noticed a few Monarch Butterflies moving southwest at very high altitude; they were mere specks in the clear blue sky. Each day during the following week, I saw Monarchs trickling through at treetop level or lower, all heading southwest. On October 7th, with strong southwest winds, the Monarchs were moving through in much greater numbers. The Butterfly Bushes in front of the Butterfly House were busy with Monarchs. I even saw a few of these large orange-and-black butterflies nectaring on the only blooming Groundsel Tree in Explore the Wild (next to the Wetlands Overlook). Other butterflies were seen that day as well, including migrant Cloudless Sulphurs, but it was the Monarchs that were the main attraction of the lepidopteran show on display that fine fall day.
So, what’s the common thread in this post? Silk. All the creatures above produce silk at some time in their lives. The orb weavers obviously produce silk to make their webs. Wolf Spiders use silk for egg sacs. And, the caterpillars (the Monarch, too, was a caterpillar perhaps only a week prior to being photographed) may use silk as a life-line and, most definitely, in the making of their chrysalides or cocoons.