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Just about every fly fishing book, magazine, fly shop or website has a hatch chart for their region.  These hatch charts generally list the hatches on various streams and the approximate dates of their occurrence.  There have been numerous requests over the years to include a hatch chart on this website.  The following is not a typical hatch chart, but only an attempt to sequentially list the major hatches, for reasons discussed below.  

 

In recent years, we have noticed increasing variability regarding the dates when many of the hatches are occurring, to the point where much of the published information for specific streams has become unreliable.  For example, on Yellow Breeches Creek, we have seen Slate Drakes a month earlier than normal, and Tricos every month of the year except February and March.  In fact, the past two years, we experienced good fishing to Tricos over the Thanksgiving weekend and through our Pennsylvania rifle deer season.

 

The window in time where hatches occur is generally related to water temperature and amount of daylight.  The timing of many hatches appears to be changing, for reasons that we can only speculate.

 

While the window for hatches to occur appears to be changing, there remains one constant.  The sequence for most hatches continues as a reliable indicator of what to expect on your next visit to a specific stream.  The calendar year is divided into four seasons: Spring, Summer, Fall (Autumn) and Winter. In my book entitled Creel Zero (see link) are selections of fly patterns that have proven over the years to catch fish when the listed hatches are present and when hatches are not evident. Also, the book contains vital four seasons fly fishing information on incorporating those flies on the water with successful results. For example, select a fly and note the season or seasons as some bugs overlap from one season to another. Next, find the fly pattern page(s) in the book or in the PDF link. Let’s say you have chosen the Grannom Caddis fly and read the pertinent information. The Grannom Caddis in the hatch sequence appears in late winter and early spring, so page to the late winter/early spring sections in the book or PDF link, and read all that pertains to the Grannom Caddis, which appears on pages 22-25. The Grannom Caddis reading will incorporate the Grannom Caddis fly pattern found on pages 113-114, the Grannom Emerger fly pattern found on pages 173-174, and the Egg-Laying Grannom fly pattern found on pages 111-112. Also, as mentioned earlier, you will find information on how and where to fish the Grannom Caddis.   As you use the hatch sequence and apply it to the Creel Zero book or PDF link, you will be able to connect the dots on which fly patterns to use for the hatch sequence and hopefully experience additional tight lines.      

 

Hatches

The following is a sequential list of important hatches in central Pennsylvania and many other locations. Not all streams have all of these insects, but the sequence is generally correct for those insects that are present.   There is also considerable overlap because of the varying duration of individual hatches.       

 

WINTER:  December 21 to March 19                           

Midges (all year)                                                                               

                                                                        

Little Black Stonefly

Little Blue Winged Olive (Baetidae family)

Early Black Stonefly

Early Brown Stonefly

Quill Gordon

Hendrickson/Red Quill

Grannom Caddis

 

SPRING:  March 20 to June 20

 

Blue Quill

Quill Gordon

Hendrickson/Red Quill

Grannom Caddis

Little Black Stonefly

Early Black Stonefly

March Brown *

Sulphurs

Green Drake

Brown Drake

Slate Drake (first brood)

Crane Fly

Tan Caddis

Sulphurs (several species)

Micro Caddis

Large Stoneflies

Tricos

Little Blue Winged Olive (Baetidae Family)

 

SUMMER:  June 21 to September 21

 

Sulphurs **

Blue Winged Olive (Drunella formerly Cornuta)

Crane Fly

Tan Caddis

Blue Quill

Tricos

Light Cahill

Micro Caddis

Black Caddis

Hexagenia

White Fly

 

FALL (Autumn):  September 22 to December 20

 

Slate Drake (second brood)

Tricos

Little Blue Winged Olive (Baetidae family)

October Caddis

Crane Fly

Light Cahill

Black Caddis

 

*Entomologists now say March Brown and Gray Fox are same species.

** Smaller in size as the season progresses.

 

NOTE: Thanks to Ken Okorn for his help in assembling the Hatches sequences.

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