North America’s main hatch event

Come hell or high water, one of the more faithful June “bustings out all over” along some Central Alberta trout streams is the annual hatch of the Salmon fly (Pteronarcys californica), our largest stonefly.

Come hell or high water, one of the more faithful June “bustings out all over” along some Central Alberta trout streams is the annual hatch of the Salmon fly (Pteronarcys californica), our largest stonefly.

In rare years, the event can take place in May, and that seemed possible this year, with no monsoon in sight and the water warming to hatching temperatures. Along the streams, things seemed normal for the first season in about the last three or four. The Western March Brown mayfly appeared just when it should, along with the wild Clematis, and some anglers were reporting trout rising to something invisible (the very dark March Brown can be very hard to see on the water, especially under overcast skies), but being able to catch them with a #12 or #14 Adams.

Then anglers started getting fast action using big, black, weighted stonefly nymphs, a clear indication that the Salmon fly nymphs were moving to the banks and shores, preparing to emerge, “hatch,” into winged adults, and mate. Then we’d all just have to for the return of the females, en masse, to the water, fluttering on the surface, to deposit their eggs, driving trout to gluttony and fly fishermen berserk in what is arguably the main hatch event of North American fly fishing.

But, as so often happens with the Salmon fly hatch, the monsoon suddenly blew in and roiled rivers and streams into torrents of peanut butter. The big bugs don’t care, perhaps would prefer, if they were sentient, that the trout can’t see, and thus eat them. When no rising trout are to be seen, frustrated anglers, thankfully, are not tempted to risk wading high, dark, and dangerous waters.

Experienced hatch chasers tell me I am plain lucky to have fished a dozen perfect Salmon fly hatches in 50 years, three times on Montana’s fabled Madison River, once on our Crowsnest, and eight or nine times on Central Alberta brown trout streams.

Fishable water or not, I never tire of watching, the hatching process, and run for my medical photography equipment whenever, usually as dark falls, I notice the massive migration of mature Salmon fly nymphs. The glistening black, five-cm long lobster look- alikes, crawl from the water that has been their home for three or four years (and through many underwater molts as they grew) and onto boulders and streamside vegetation for the final molt-“hatch,” into the winged adult stage: another of the great miracles of the Manitous.

If an arriving nymph does not quickly find a suitable anchor point, it will re-enter the water, then climb out and up elsewhere. I surmise they must keep their chitin, their nymphal skin, wet until they are ready.

When the nymph finds a spot to its liking, it gropes for the best foothold. Then the creature becomes quiet, almost prayerful, like a weight-lifter before the lift. Gripping the rock, reed, or branch with its claws, the nymph humps its body, again and again, putting tremendous pressure on the centre line between its wing pads.

Slowly, a white crack appears behind the head, then, as the crack widens, a blaze orange spot, the head markings of an adult salmon fly, glows in the gloom. Slowly the huge adult hauls itself through the small hole in its nymphal case to stand atop the shuck, drying pinkish, clumped, vertical wings that eventually unfold, flatten over the back, and harden into the smoky-grey, nylon-stocking appearance of the adult Salmon fly wing.

Light and wakefulness have always failed me before I have seen completion of the wing hardening, but from emergence of the nymph from the water to emergence of the adult from the case, takes approximately 15 minutes in each insect. By mid-morning after one of these events, empty nymphal shucks cling to rocks, reeds and branches, and it is impossible to seine a live, mature, Salmon fly nymph from the water.

When the insects are dry and their wings fully hardened, they fly up into streamside trees and bushes where the sexes locate each other with a drumming procedure and mate.

For anglers, the wait can be excruciating for the main fishing event, when the females fly en masse to the water to lay their eggs and start the whole life cycle over again.

On one of my Montana trips, snowy, cold weather kept the gravid females “grounded” in the trees and bushes for 10 days. One year on Prairie Creek, they hung in the trees for a week, and then flew the egg-laying run at midnight.

World-wide there is a very small group of photographers who specialize in photographing aquatic insects of interest to fly fishermen.

Up until recently my 20 images of the progression of the Salmon fly emergence sequence from start to finish was the only one I was aware of; and it has never been published intact because of space limitations and because I was holding it for another book.

Fortunately, the current issue of Fly Fisherman magazine carries excellent shots of some of the stages of the hatch from Arlen Thomason’s book, “Bug Water.”

Bob Scammell is an award-winning outdoors writer living in Red Deer.

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

Red Deer RCMP say a 30-year-old man faces sexual charges against a teen. (File photo by Advocate staff)
Innisfail RCMP arrest man following ‘lengthy pursuit’

Innisfail RCMP say a “lengthy pursuit” through a rural area ended with… Continue reading

Red Deer South MLA Jason Stephan speaks in the Alberta Legislature on Wednesday in this image from his Facebook page.
Red Deer MLA Jason Stephan sounds off on socialism in anti-lockdown speech

Red Deer-South MLA Jason Stephan has applauded his government’s COVID-19 response, saying… Continue reading

(Photo by Paul Cowley/ Advocate Staff)
Mask bylaws not popular in rural areas

Red Deer and Blackfalds bylaws requiring masks in public places kick in on Monday

A GoFundMe campaign to support a Stettler couple following a fire has raised more than $3,000. (Contributed photo)
Family pet dies in Stettler fire

GoFundMe page has raised more than $3K so far

Canadian Olympic gymnast and National Sport School alumni Kyle Shewfelt announces his retirement in Calgary, Thursday, May 21, 2009. Calgary's board of education will close the National Sport School that has produced Olympic and Paralympic champions for 26 years. THE CANADIAN PRESS/Jeff McIntosh
Calgary’s National Sport School to close, looks to join a different school division

Calgary’s National Sport School to close, looks to join a different school division

Canada's Erica Wiebe, left, celebrates after defeating Nigeria's Blessing Onyebuchi, right on the ground, to win Gold medal in women's FS 76Kg wrestling at the Commonwealth Games on Gold Coast, Australia, Thursday, April 12, 2018. THE CANADIAN PRESS/AP-Manish Swarup
Canada’s Olympic champion wrestler Erica Wiebe eyes return to competition

Canada’s Olympic champion wrestler Erica Wiebe eyes return to competition

Louisiana-Lafayette running back Elijah Mitchell (15) is tackled by Coastal Carolina linebacker Enock Makonzo (43) and safety Cameron Mitchell (49) during the first half of an NCAA football game in Lafayette, La., Wednesday, Oct. 14, 2020. It's already been a season to remember but Canadian Enock Makonzo and the Coastal Carolina Chanticleers will chase two more firsts Saturday. THE CANADIAN PRESS/AP-Paul Kieu
Canadian Enock Makonzo, Chanticleers chase Sun Belt East regular-season crown

Canadian Enock Makonzo, Chanticleers chase Sun Belt East regular-season crown

Atlanta United's Mo Adams, right, challenges Toronto FC's Alejandro Pozuelo during first half MLS soccer action in East Hartford, Conn., Sunday, Oct. 18, 2020. Toronto FC's Alejandro Pozuelo says he finished the season with an injured leg. THE CANADIAN PRESS/AP-Jessica Hill
Toronto FC ready to refocus on future as long, hard season comes to an end

Toronto FC ready to refocus on future as long, hard season comes to an end

Federal Health Minister Patty Hajdu and Vancouver Mayor Kennedy Stewart speak to the media during a visit to the Molson Overdose Prevention Site in Vancouver's Downtown Eastside, Thursday, January 16, 2020. City councillors in Vancouver voted unanimously this week to ask federal officials for an exemption to Canada's Controlled Drugs and Substances Act, a decision advocates hope will blaze a trail for the decriminalization of small amounts of illicit drugs for personal use in other municipalities. THE CANADIAN PRESS/Jonathan Hayward
Advocates aim to shape ‘Vancouver model’ for drug decriminalization

Advocates aim to shape ‘Vancouver model’ for drug decriminalization

Senator Murray Sinclair appears before the Senate Committee on Aboriginal Peoples in Ottawa, Tuesday, May 28, 2019. Sinclair is planning to leave the Senate early next year. THE CANADIAN PRESS/Fred Chartrand
Sen. Murray Sinclair, former head of TRC, set to leave the upper chamber next January

Sen. Murray Sinclair, former head of TRC, set to leave the upper chamber next January

Carolina De La Torre, right, owner of Arepas Ranch in Calgary, poses for a photo with her husband in this undated handout photo. The Venezuelan woman who believes she was used as part of Jason Kenney's argument not to lockdown restaurants in the province remembers her encounter with the premier as a lot less dramatic than he suggested. THE CANADIAN PRESS/HO, Carolina De La Torre *MANDATORY CREDIT*
‘No crying’: Venezuelan refugee Kenney cited says interaction was less dramatic

‘No crying’: Venezuelan refugee Kenney cited says interaction was less dramatic

Prime Minister Justin Trudeau listens to a question from a reporter during a bi-weekly news conference outside Rideau cottage in Ottawa, Friday, Nov. 27, 2020. THE CANADIAN PRESS/Adrian Wyld
Trudeau feels most Canadians could be vaccinated by September 2021

Trudeau feels most Canadians could be vaccinated by September 2021

Most Read