Among the largest and most commonly seen spiders in the Fall are the Spotted Orbweavers (Neoscona crucifera and less commonly Neoscona domiciliorum). With webs that can be over 2 feet wide and their tendency to attach them at just above eye level to structures such as buildings, these seem to call attention to themselves this time of year.
During the earlier part of the year you likely never noticed them. Not only were they much smaller as spiderlings, but they hide during the day. They would tear down and consume their webs every morning, so you often didn’t notice their webs they constructed nightly. They did this to avoid daytime predators such as birds or wasps from finding them. Mud Dauber wasps for example often sting and paralyze many of these when they’re young, stashing them in their mud nests as living paralyzed food for their own babies.
But by Fall, they’re often too big for wasps to eat. Many wasps have also concluded hunting and egg laying by this late in the year. So the spiders sometimes hang out during the day. Many birds also don’t go after them as much, having no babies to feed or they themselves leaving on migration South. Prey also gets scarcer as it gets colder, so leaving the web up during the warmer day increases the chance of a catch. Consequently, Spotted Orbweavers don’t hide as much and also don’t tear down their webs and rebuild them at night as much once autumn arrives.
So while there are definitely fewer of them around, they’re bigger and hide less. They also often choose to build their webs around our porch lights and buildings, as the artificial lighting attracts insect food to get snared in their webs. They now stay out more often and tear their webs down less, all the way until the first few frosts kill the adults. Their webs are good at intercepting all sorts of aerial or jumping prey.