Fall Mayfly and Caddis Hatches

There are still a few hatches left for the Smart Fly Angler

Many fly anglers believe that most of the fly hatches are over at this time of the year but they are mistaken and may miss of the best fishing of the year if they are on the right stream at the right time.  A few words of caution about these hatches.  First, they are not on every stream.  Second, they may not be heavy depending on the stream that you are on. Or they may be heavy on some sections and spotty on others.  Third, the waters are sometimes low and the fish are spooky. Fourth, their emergence period is sometimes very unpredictable including their spinner falls.

Here are our favorite autumn hatches and a short description of each:

The Sulfurs: (Ephemerella rotunda (invaria).  Yes, on many streams these mayflies continue until it's too cold.  The size of these flies diminishes greatly from previous hatches.  These flies are in the 18 range.  The coloration about the same which is variable shades of sufur, tan and ruddy bodies.  Small sulfur nymphs work very well at this time of year.  Emergence is typically earlier than usually in the mid afternoon.  Spinner falls are very sporadic from morning to evening depending upon the temperature.  Colder days usually mean earlier returns.

Blue Winged Olives: (Baetis tricaudatus and related species). The mayflies have many broods per year and basically emerge most of the year on both freestone and limestone spring creeks.  They are usually 18-24 at this time of year.  They emerge mainly in small pockets from the edges of the stream because the nymphs have specific current requirements.  Emergence can be heavy in one riffle and almost nothing in the riffle next to it. Spinners and duns can be on the water at the same time.

Dark Blue or Chocolate Quill (Paraleptophlebia mollis and related species).  Many streams have these mayflies but they are seldom in great quantity.  The cousin of the early season Blue Quill (Paraleptophlebia adoptivia) the nymphs are current and substrate specific to the sides of the stream. Emergence usually spotty but the flies are around size 14 (or larger on some waters) so the fish will rise for these meaty flies.  The Chocolate spinner works fine for the imagoes. Brownish translucent nymphs with maribou or similar materials for gills.  Best hatches usually late September to Mid October.

The Large Golden Caddis (Pycnopsyche lepida)  The classification of this large caddisfly has changed but we will use the older name.  These caddisflies are large size 8 to 6 and cases are made of wood and debris to stones as the instars get near emergence.  Golden hopper type patterns  work well for these flies which come off sporadically during the fall months.  These are caddis are even found on smaller waters so be prepared.  Trout are not usually too selective for these flies but hold on because you'll find out if there are any lunkers in the stream when these flies are on. Emergence can be any time of the day.