Beating trees should find you some: hold a butterfly net, a beating tray or an upside-down umbrella under a slender branch and whack the top of the branch with a stick. All sorts of invertebrates will fall out.
There is also sugaring. You make a mix of treacle, wine, various components and paint it on a fence post. Moths and other insects should come to it. I never do it so can’t give you tips but I bet there are plenty of recipes online. If you haven’t got a suitable surface to paint, you can soak strips of cloth in the liquid and hang them over branches.