|
|
|
|
|
|
Caddisfly Emergence and Pattern Guide
The following guide includes general descriptions of the physical characteristics, flight times, and seasons of emergence for the most important caddisflies in the region under the purview of our Trip Planner. Suggested patterns are also given. Individual hatch guides for the most prominent streams in the area, with individualized season information and flight times, are given on the appropriate sub-page in the Our Waters page. My caddis entomology is not good, but it doesn't really have to be, as trout are usually less wary when eating caddis than when eating mayflies. Insects are listed in decreasing order of general importance. Please note that some insects are more important on some streams than others, however. Also note that this guide does not cover insects common in the Paradise Valley spring creeks, which are more varied.
The most important things to remember about caddis emergences in general are: 1. they usually happen in the afternoon or evening, 2. caddis emerge more energetically than most mayflies, so rises are usually more violent, and 3. emergers and cripples are usually as good or better a bet than adult patterns.
Please contact us for more information on area hatches and the flies to match them.
The first portion of the following guide consists of an emergence table and notes. The second portion consists of longer descriptions of each listed insect.
Key for the following table:
| First Column: | Common or Latin name of the insect |
| Second Column: | Usual size of the insect |
| Third Column: | Predominant shades of the adult insect |
| Fourth Column: | Time when emergence typically occurs |
| Remaining Columns: | Usual months of emergence. A capital X signifies a hatch of primary importance, a small x signifies a hatch of secondary importance. No hatch usually occurs in months marked with a blank. |
Caddis Emergence Table
| Name | Size | Coloration | Time | Month of Emergence | |||||||||||
| J | F | M | A | M | Jn | Ju | A | S | O | N | D | ||||
| Hydropsyche | 14-16 | tan and brown/olive | afternoon and evening | x | X | X | x | ||||||||
| Green Caddis | 14-16 | gray or brown and green | afternoon and evening | X | x | x | |||||||||
| Little Sister Sedge | 16-18 | tan or gray and olive | evening | X | x | x | x | ||||||||
| Oecetis or Nectopsyche (Longhorn Caddis) (1) | 14 | pale tan | afternoon and evening | X | x | ||||||||||
| Mother's Day Caddis | 14-16 | speckled tan and dark olive | afternoon | X | x | ||||||||||
| Small Brown Caddis | 14-16 | brown and olive | afternoon | x | X | X | |||||||||
| Great Lake Sedge or Travelling Caddis | 8-10 | tan or light brown | afternoon and evening | X | X | ||||||||||
| Large Brown Caddis | 10 | brown | afternoon and evening | x | |||||||||||
Notes:
| 1. | The Oecetis or possibly Nectopsyche caddis is by far the most important caddis on the Firehole in June. I have every reason to believe it hatches throughout the summer, but the Firehole is too warm to fish in July and August, so I have left these spaces blank. The Firehole is the only stream where I have consistently seen this hatch, but I have seen a few on the Gibbon as well. |
Discussion of Insects
| Common Name | Scientific Name (if known) | Discussion |
| Speckled Tan Caddis | Hydropsyche | The Speckled Tan Caddis is by far the most common summer caddis in our area. It hatches on all streams, large and small, though it is perhaps more common in faster stretches than slow. Look for it in the evening. As with most of our caddis, my favorite patterns are X-Caddis and Partridge Caddis, while if I feel fancy I'll fish a Sparkle Pupa. |
| Green Caddis | Rhyacophila | Wonder why the beadhead Prince works so well? This is one reason why. The green-bodied pupae of this free-living caddis tend to drift in riffles throughout the region. An X-Caddis matches the adult/emerger. |
| Little Sister Sedge (?) | Cheumatopsyche (?) | This one I'm unsure about. There's a brand of small (#18 usually) caddis that hatches in many Yellowstone waters in July and September. In July it's usually mixed in with Hydropscyhe and in September I'm usually fishing BWO hatches or targeting runner brown trout, so it's not one I fish much. This insect could just be a small Hydropsyche or even something else. Regardless, a Partridge Caddis matches it. |
| Longhorn Caddis | Oecetis or Nectopsyche | Whatever the true genus, this is a crucial caddis in June on the Firehole. It is also present in September. Its two key identifiers are its extremely long antennae and its golden tan, almost ginger, wings. In flight, this insect looks much like a mayfly, because its tails stream out along its body and extend behind it as much as one and a half body lengths. Key patterns are Oecetis X-Caddis, Wiese's Lightning Rod Caddis, Oecetis Cripples, Wiese's Foam Isis Caddis, and, for the larval form, Tan Shimmer Dips. |
| Mother's Day Caddis | Brachycentrus | THE hatch on the Yellowstone in the spring. Though the BWO and the streamer fishing are more consistent, the week or so right before the high-country snowmelt hits in late April or early May is when to be here if you want caddis up your nose, in your clothes, and in plenty of fish. In most respects this insect resembles the Hydropsyche, with the key difference being its darker body. Key patterns are again the Partridge Caddis in size 16, and even a Coachman Trude, especially in dirty water or when your fly seems to be getting lost among millions of naturals. |
| Small Brown Caddis | Lepidostoma (?) | Another I'm unsure of. Important in September on the Firehole. A similar insect is around during the explosion of hatches on most freestoners in mid-July. A #16 Henryville or brown-winged Elk Hair matches this fly well. |
| Great Lake Sedge | Phryganeidae | When you see vee-wakes cutting across the surface of Trout Lake or other stillwaters, these caddis are emerging. The pupae swim energetically towards shore before emerging, because the adults are so large they make easy pickings for birds if popping directly through the surface. You'll still see robins dive-bombing the vee wakes. Fish a large Tan Woolly Worm or Sparkle Pupa on a slow sink tip and strip quickly. Whammo! |
| Large Brown/Tan Caddis | Arctopsyche (?) | This large, brown or tan, somewhat rare caddis is sometimes seen on the Yellowstone or Gardner in July. It's a big, imposing fly, best imitated by a Hare's Ear Stimulator, large Goddard Caddis, or even a small Letort Hopper. There's a good chance fish take attractors and terrestrials like Stimulators and Turck's Tarantulas as this fly, since, though it's rare, it makes a good meal. |
|
Contact Information |
|
| Phone: | (406) 848-7314 |
| Address: |
PO Box 196 202 Second Street South (US-89) Gardiner, MT 59030 |
