I've long held that this is the time of the year when the adults of several common web-spinning spiders in Ohio reach their maximum population densities. I can't cite any data to support this belief. It's based entirely on observing their gossamer creations; sometimes annoyingly up-close while hiking forest trials.
There are over 600 species of spiders found in Ohio and most feed almost exclusively on insects. The spiders that are currently dominating (draping over?) landscapes are the Sheetweb Weavers (family Linyphiidae); the Funnel Weavers (family Agelenidae); and the Orb Weavers (family Araneidae).
Sheetweb Weavers
Sheetweb weavers construct several types of webs depending upon the spider species. Some species spin flat or slightly curved webs that overlay vegetation and rival the sizes of webs spun by funnel weavers. However, their webs do not include a funnel. The spiders hide beneath one edge of the web, or within the plant foliage along the edge of the web, to await their prey.
One of the more interesting sheetweb weavers is the bowl and doily weaver (Frontinella communis). This is one of the few spider species with males capable of producing webs; however, females still dominate web weaving.
The spider constructs a complex web structure consisting of distinctly bowl-shaped webbing suspended from plant stems by a crisscrossing array of silk threads; this is the "bowl" in the common name. The bowl is anchored below by a horizontal array of interwoven silk threads; the "doily." Flying insects drop into the web-bowl after bouncing in pin-ball fashion off the interlacing silk threads used to suspend the web. Of course, when they drop into the web-bowl, they fall into the "arms" (and fangs!) of the awaiting spider!
Funnel Weavers
Funnel weavers produce large, flat, sheet-like webs spun across turfgrass, under rocks or boards, or over the branches of shrubs such as yews and junipers. The webs slope gently towards a narrow funnel or tube where the spider resides, awaiting its next victim. The spiders are medium-sized and resemble small wolf spiders. Funnel webs may measure more than 1' across and can become very evident with dew, or when they snare dust during droughty conditions.
Orb Weavers
These are the true structural engineers of the spider world. As their common name describes, orb weavers produce flat, circular (orb) webs. The webs are intricate structures involving both sticky and non-sticky silk.
Non-sticky silk is used for "radial threads" which radiate from a central point like spokes on a bicycle wheel. The non-sticky silk is also used for "frame threads" which encircle the web like a bicycle wheel to hold the radial threads in place and to attach the web to supports such as plant stems. "Spiral threads" are composed of sticky silk arranged in a spiral pattern emanating from the center of the web; it's the sticky silk that captures the spider's prey.
One of the most common "in-your-face" orb weaver is the Arrowhead Spider (Verrucosa arenata). The spider is so-named because of its arrow-shaped abdomen. Arrowhead spiders sport variable color schemes; however, all may be viewed at face-height in the middle of their webs stretched across forest trails. I passed through three webs in rapid succession this past weekend and couldn't decide who was more perturbed; me or the spiders.
A "stabilimentum" is a vertical pattern off dense silk centered in the web that is produced by many orb weavers. The stabilimentum produced by the large, showy Black and Yellow Garden Spider (Argiope aurantia) usually has a zigzag pattern giving rise to the alternate common name of "Zigzag Spider." The dense webbing reflects ultraviolet light which attracts insects to their doom.
Look closely between the branch tips of shrubs and you may spot the diminutive Trashline Orbweaver (Cyclosa spp.). The silk in their stabilimentum enshrouds the drained bodies of previous victims; the morbid structure is responsible for the "trashline" common name.
The spiders rest in the middle of their trashline. Their small size and mottled coloration make them very difficult to see among their similarly sized and colored bundles of trash. Indeed, research has shown that the trash bundles serve to confuse predators, such as birds and wasps, intent on making a meal of the spider, and the greater the number of bundles, the greater the confusion.
Don't Kill These Bio-Allies
Spiders eat insects and research has consistently shown they remove a significant number of pests that we would have to deal with otherwise. Of course, numerous arachnid engineered insect traps draped over low growing shrubs can look like Halloween decorations.
Continually removing the webs will eventually cause the spiders to take a hint and relocate elsewhere. If you see the spider on the web, just shoo it off before destroying their web so you don't accidentally commit an arachnicidal act.
