Is it possible that two rivers no more than thirty miles apart could have two distinctly different caddis that appear during the same time period?
Yes. I know I should probably leave it at that, but that's not the whole story.
PA has 6 recorded Brachycentrus
species, known variously as Apple Caddis, Shadfly, Grannom, Black Caddis, Penn's Creek Caddisfly, or even Mother's Day Caddis. Most of these hatch during the same general time period (mid-April to mid-May). B. americanus
is an exception. Its later, longer emergence often extends from late June through August in the Northeast.
species that is known as the Apple Caddis on the Delaware is B. appalachia
. This species has very light wings (almost white) upon emergence, but goes through stages of darkening as the adults age, ending up with a brownish or grayish wing and a darker body. This species is also found on the Beaverkill, Willowemoc, and Little Beaverkill. Adult specimens from those waters are dated from April 30th to May 7th in the collecting record.
species that is found in those same waters (Delaware/Beaverkill system) is B. solomoni
, named for fly fishing writer Larry Solomon. This is a darker species, but it emerges at the same time. Adult specimens in the collecting record are dated from April 29th to May 7th. (These include the holotype collected by Solomon from the Beaverkill at Roscoe.)
Here is another example of appalachia
from that same river system (notice Jason's comments on the darkening): http://www.troutnut.com/specimen/727
Here is another appalachia
from the same system that shows the dark wing veins:
And here are two darker specimens collected from the same system at about the same time. (These are still listed as Apatania
, but Creno thought they were Brachycentrus
, and he should know. They might even be solomoni
The name Apple Caddis is usually applied to B. appalachia
. This is a newer nickname reflecting more modern usage and a shorter fly-fishing tradition on the Delaware. The name Shadfly or Shad Fly (which is also sometimes applied to Green Drakes/Ephemera guttulata
) is much older and reflects older traditions on the Beaverkill. Its application to Brachycentrus
species on the Beaverkill can be traced back (at least) to Louis Rhead's attempt to describe Catskill hatches in American Trout Stream Insects
My apologies in advance for droning on about this.