Ok, found another article that states it is kidney bean leaves and more specifically the underside of the kidney bean leaf having the hooks. Now, if only they’d said which side to place upwards. If the bedbugs crawl across the floor, then bottom side down or if they fall off from up high somewhere and onto the leaves then bottom side up. Maybe just go with half one way and half the other. Wonder if this works with other bugs? Wonder if other varieties of bean leaves work, too. Squash and cucumbers have hairy leaves but it doesn’t slow down squash bugs so there’s something unique with the kidney bean leaves. This might explain why beans usually aren’t bothered by bugs. Hmm, something to think about.
http://www.redorbit.com/news/science/1112819742/bean-leaves-natural-pesticide-bedbugs-041013/
You know, might be worth a try to grow cukes and such in the thick of kidney beans.
I’m guessing the leaves are as attractive as others. I’ve never seen a bean leaf with so much as a gnat on it.