Watching water temperature helps to determine when to fish certain insect imitations. If fly fishers haven’t seen the bugs, water temperature can still tell you they are there. With the way water temperatures have been going, caddis are here. And not just on the surface. The caddis activity is from top to bottom. The bugs are moving. Activity is happening at every depth in the river. Nymphs are crawling on the bottom. Pupae are rising towards th…