Before the work of Gary LaFontaine who recently died from Lou Gehrig's disease, the underwater lives of caddis flies and their effects on trout feeding behavior was largely misunderstood. Gary spent a lot of time underwater with scuba gear studying the aquatic habits of these secretive insects. He observed how trout responded to caddis larvae and pupae differently. He also observed diving, egg laying adult female caddis at very close range. Gary took the time to see these insects from the same prospective as trout see them. He did this work while studying for a biology degree. His thesis became the most definitive work on caddis flies ever produced. Gary's work disclosed several facts hither to unknown about caddis flies. Probably the most revolutionary find is that when many species of caddis pupae rise to the surface their abdominal areas are surrounded by an air sack. He watched from underwater as trout keyed on these air bubbles as they fed. The LaFontaine Sparkle Pupa series was developed from this research. Over a ten year period Gary's research was turned into a book that fly fishers could understand. It was called Caddisflies. Caddisflies is required reading for anyone who desires to be a complete trout angler. Unfortunately it is out of print, so look for a used copy.

Here are other facets of caddis fly behavior that trout anglers will find useful: All caddis larvae are subject to periodic behavioral drift cycles. During these periods entire populations are exposed to trout which can key on them exclusively. During these times the larvae pattern listed here have proven very productive. The Glass Bead Larva are the most realistic available for representing net spinners and free living varieties. The Peaking Cased Caddis is a great cased-caddis larva pattern. These flies are most effective while being fished close to the bottom. Split shot may be used and the flies should be presented "dead drift".

Caddis' go through metamorphous under water. During a caddis hatch, pupae rise from the substrate to the surface. Some drift along the bottom for many yards before they rise. Bead Head Caddis Pupa and Deep Sparkle Pupa are productive patterns during the earliest stages of the hatch. They are fished close to the bottom very much like caddis larva and other nymphs.

As the pupae rise to the surface an air bubble often surrounds them. This shiny bubble containing the helpless insect becomes a target for feeding trout. The pupae are most vulnerable while trapped in the surface film. The Emergent Sparkle Pupa is the most proven pattern type for this stage of the hatch. However, if you try a Glass Bead Caddis Pupa, you will probably be amazed at how productive it is. These flies can be fished down stream, across the current, under light tension. If short strikes occur, try feeding a lightly held shock loop when you feel the pull of a taking fish.

Some caddis species lay their eggs by diving through the surface of the water and ovipositing on the substrate. This usually happens right at dark. Large trout will be making very splashy rises with no apparent hatch. An Emergent/Diving Caddis in the right color and size is often the answer.