Banded Garden Spider and its Web

Ever since a Banded Garden Spider (Banded Argiope) hung its web in our garden many years ago, it has been one of my favorites. Now is the time of the year to watch for webs and to find this and other spiders. Many spiders mature in late summer and the early morning dews highlight webs that we might otherwise miss.

Earlier this week I spotted this Banded Garden Spider in Eliza Howell Park while I was walking through the wild flowers.

These spiders wait in the middle of the vertical orb web, in an inverted position, and hold their legs together so that, at first glance, it looks like they have only four legs instead of eight. They can feel when an insect is caught in the web and hurry to subdue it and wrap it in silk for eating later.

Many other spiders hide at the edge of their webs. The fact that Banded Garden Spiders position themselves at the center of the web, together with their practice of remaining on the web for much of the day, contributes to my observation pleasure. It has poor vision so one can come close without disturbing it, as long as they cannot detect an intruder with their other senses. It tends to drop down when there is contact with the web or with the branches that support it.

The web is large and basically circular. Banded Garden Spiders are among the spiders known as orbweavers and the webs are called orb webs. These spiders are large, but note how small they look in the center of the full web.

The spider in the middle here (difficult to see) looks different from the one in the first picture, but it is the same one. Since it is on a vertical web, it is possible to view both its top side and its underside. We are now looking at the underside.

Located on the underside, near the rear end of the abdomen, are the spinnerets, the external ends of the silk glands.

Large orb webs, especially when visible with dew drops, provide an opportunity to note the different threads. The radii threads (spokes) that go from the outside toward the center of the web are not sticky, but the spiral threads are – and are the ones that capture and hold the prey.

This orb web, made by another orbweaver, not a Banded Garden Spider, shows the typical orb web shape.

In the next picture, a close-up of a Banded Garden Spider and part of its web, one can see that the sticky threads do not touch the center, where the spider waits. When an insect is caught, the spider travels to it on the radii to subdue it.

Not all orbweavers incorporate the zig-zag looking arrangement near the hub (“stabilimentum”) in their webs, but Banded Garden Spiders do. The stabilimentum was visible in the pictures above and is shown again here.

The function of the stabilimentum is not fully understood. While areneologists (spider experts) seek to learn more about this part of the web, the rest of us might notice it and wonder what the spider knows that we do not.

I am very far from being an areneologist, but my appreciation of the world of spiders is greatly increased by having access to some of their work, including this 2018 book.

There are other types of spiders and other kinds of webs present now in Eliza Howell Park. This is the best time of the year for web watching – from now until the fall frost.

An August Walk: Phenological Observations

As I wander the park these August days, much of my attention is focused on the beginning of fall bird migration and on the continued blooming of insect-attracting flowers. There is so much more to observe, however, and recently I noted a variety of other seasonal phenomena.

I saw all of the following on one recent morning walk.

Blue-gray Gnatcatcher Nest

I came across this tiny nest that had fallen under the wild black cherry tree where I watched a pair of gnatcatchers as they constructed this twenty-foot high nest in late May. And I watched them, as well, as they fed the young in the nest in June. The fallen nest provides a good opportunity to note the construction, including the bits of lichen on the outside which helped to camouflage it on the tree limb.

Orbweaver and Web

This is a great time of the year to find spider webs, often made more visible by dew drops or raindrops. This orbweaver (Marbled Orbweaver, I think), is hanging out upside down under the web as it waits for prey.

Virginia Creeper Berries

One of the native vines that grow in the park is Virginian Creeper. It always catches my attention when the berries change from green to blue on red stems. Virginia Creeper is sometimes confused with Poison Ivy, but there are several differentiating characteristics. One is that creeper berries are blue when ripe while ivy berries, when ripe, are whitish.

Bald-faced Hornet Nest

Every year I find a number of Bald-faced Hornet nests in the park, most them quite high in trees. This is the first one I found this year and it is quite low. These hornets, really a type of wasp, defend their nests vigorously if one gets really close, but I have found that a few feet away is safe. (For more, see my post on December 19, 2017: “Bald-faced Hornet Nests.”)

Variety of Mushrooms

After rain in late summer, mushrooms pop up — in various locations and in various shapes and sizes. These are some that I saw on the walk. Maybe next year I will try to identity them, at least the most common ones. For now, I am just appreciating the variety.

Developing Acorns

There are many different types of oak trees in Eliza Howell; this one is a type of white oak. The acorns are not yet fully grown in most species and it is fascinating to watch how they mature. In some cases, the nut has to grow out of the cap that originally covers it almost completely.

Snail Climbing Plant

These land snails (Brown Lipped Snails) are common in the unmowed sections of the park on the south side between the road loop and the woodland bordering the river. In late summer, they often climb stems as they eat decaying plants and grasses. I almost always find them on my walks among the wildflowers.

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Phenology is the study of the annual life cycle events of plants and animals. When I use expressions like “at this time of year” and “seasonal,” I am very conscious of how much awareness of the annual cycle is at the heart of nature observation and study.

Season after Season: A Taste of Fall

When I began this blog three months ago, the first post was entitled “A Sense of Wonder.” That post included these comment: “The park…provides an excellent opportunity for me to experience the natural world in its wonder and excitement and beauty, right in the heart of a major urban area. I continue to be excited by what nature presents in season after season.”

Most of my posts are on a particular theme. As a result, much of the beauty and wonder and excitement of the park does not get presented. Perhaps, from time to time, a seasonally-based collection of photos may be of interest. So I opened my gallery today and selected a few pictures. For no important reason, the season for today is Fall.

Asters

Fog in September

Butterfly Weed seeds

 

Cottonwood

This is a taste of Eliza Howell Fall.