Osage Orange, Hedge Apple, Horse Apple, Bodock, or even Maclura pomifera if you're so inclined...my kids always called these "brainy balls". And if you hate spiders, they're your new best friend.
We discovered it years ago, just as we were beginning to see brown recluse spiders in the house (hello, ozarks). With a baby in the house, this was particularly scary to me. Hiring an exterminator was expensive, but we saw no choice. Thankfully, we had an awful time getting him to return our calls and in the meantime, someone shared this tip with us and it worked beautifully. Two weeks later, when the exterminator finally called back, we were able to say , "Nevermind. We no longer have spiders."
As these beauties decay, they get sticky and apparently stinky, though I've never smelled them myself. We toss them under the house, spaced out about every 10 ft. This stuff is so effective, someone was even awarded a patent this year for an osage orange insect repellent. A chemical in them is supposed to be good for repelling mosquitos, though I have no idea how you'd go about making an extract.
The trees themselves were commonly planted as wind-breaks and used as hedges, hence the name Hedge Apples. The wood from the tree is supposed to be a superior bow-making wood.
Brainy balls are all over the ground RIGHT NOW, so hunt some up and toss them under your house for a spider-free autumn!