The arachnid seemed to be dragging the winged insect by one of its threads as it ran across the ground. But it turned out that the arachnid was the one under attack. The winged insect repeatedly struck at it, until it finally curled up and lay still. Then the winged insect landed on top of the body and tried to fly with it. He could only manage short hops. Gradually, it managed to drag the arachnid to the base of the tree, and then began climbing. I watched until they vanished into one of the higher branches.
I guess it was all about food. It was roughly the equivalent of me walking home from the local Safeway, carrying the store's entire stock of beef. I'm very impressed by the insects. I'm very glad they aren't as big as me.