Fly Fisherman's 2023 HopperCast

“Sick day” planning for hopper-fishing season starts here.

July 30, 2023 By Josh Bergan

EDITOR'S NOTE: The Fly Fisherman HopperCast grasshopper forecast will be an annual project that aims to give fly anglers an idea of what to expect at one of the most exciting times of the year. Be sure to check back next summer for 2024's projection!

Grasshoppers (Orthoptera), piscatorially known as hoppers, are terrestrial insects that inhabit grassy areas, meadows, and fields. Hoppers are known for their distinctive flight, characterized by short, erratic bursts, and their propensity for falling into the water, providing a substantial food source for trout. These insects can play a significant role in the diet of trout and cause explosive eats from them, making them attractive offerings for fly fishermen.

So how is 2023’s hopper season looking? Follow along as we try to prognosticate what the coming weeks hold for fly anglers seeking their “hoppertunity.”

Hopper fishing is often best in arid, high-plains desert areas like southwest Montana and western Wyoming. In a nutshell, if ag producers use big center-pivot irrigation systems that draw water from nearby rivers, it’s likely a good place for hopper fishing.

So what are the factors of a “good” hopper year?

Weather, both from the previous fall and winter and the current year, plays a big role in hopper populations, along with many other factors. Some important things that can lead to big hopper years include:

Warmer than average temperatures that year: Warm air temperatures are ideal for grasshoppers, as it allows them to develop and reproduce more quickly.
Abundant food sources: Grasshoppers feed on a variety of plants, and the availability of food sources plays a large role.
Low levels of predation: Grasshoppers are preyed upon by a variety of animals, and if their populations are low, hopper numbers will be up. This can happen due to a variety of factors, including habitat loss and climate change.
Wet springtimes: But not too wet as fungi and parasites that can kill grasshoppers might also exist in particularly wet springs.

As for the timing of when trout start to key on hoppers, editor/publisher Ross Purnell had this to say after his hopper-fishing expedition to Patagonia in 2014: “Harvest time is hopper time.”

“Many longbeard fly fishers have learned to expect mayfly hatches around phenological events, for example in the East, Hendricksons hatch within a few days of the first blooms of forsythia, and Sulphurs hatch at the same time you see white flowers of mountain laurel,” he wrote. “Close to harvest, the irrigation sprinklers are turned off so the crop can mature and dry (you can’t bale wet hay, or combine wet grain). When the water is turned off (or late summer becomes naturally dry) the hoppers migrate from the brown pastures and swathed hayfields to verdant creek and river bottoms where the grass is still growing. Like all living creatures, hoppers need water to survive, and they get almost all of their water from the green plant life they prefer.”

In the Rocky Mountains, this typically starts around late July.

The biggest hurdle anglers might face this year and moving forward is high water temperatures. We continue to hear about trout populations declining right on schedule with climate scientists’ predictions regarding the expected reduction of trout waters. For example, “hoot-owl restrictions” went into place on Montana’s Lower Madison River on July 12 this year which is historically quite early, despite a favorable spring precipitation and cool temps. Many other area rivers followed suit with heat restrictions that same month. Always prioritize fish health over big-fish or fish-count temptations.

Furthermore, any given day’s best hopper fishing typically occurs during the warmest part of the day during this warmest part of the year. Take water temperatures throughout the day and consider starting cocktail hour once your thermometer reads 68 or above. Unfortunately, this can leave a only short window for good fishing.

“When hoppers are the major seasonal food source, the river on a crisp, damp morning can be as lifeless as a retirement home,” said Purnell’s article from 2014. “It’s not just that the trout aren’t on hoppers, it’s that they’ve switched off altogether until the afternoon ‘hatch.’”

Northeastern Nevada, for example, recently experienced a plague-like outbreak of Mormon crickets, in which hospitals and retail businesses reportedly had to hire staff to sweep them off the sidewalks and entrance areas. The South Fork Humboldt and Bruneau rivers, along with area stillwaters, could all be good places to plop a Mormon cricket pattern this year.

Ants, another type of terrestrial bug, are seemingly a culinary treat for trout, as ant flies can be more effective than hoppers at times. You can fish ants any time of year, but they are particularly effective when the trout are already looking up for the meaty grasshoppers.

According to fishing writer Jim McLennan: “We may not know when flying ants are going to appear on the water, but when they do, the trout eat them with gusto. There has been much speculation on what it is trout like about ants, including suggestions that it's their acidic taste, but it's hard to know about that one.”

Beetles have a similar reputation to ants as being trout delicacies. As fishing legend Cathy Beck said, “Beetle patterns are nothing new to our sport as fly tiers for many years have been coming up with ideas to imitate the beetles that find their way into trout streams… It was (Vincent) Marinaro's little Jassid beetle that fooled many of the most selective trout in his prized Letort Spring Run.”

Bees and wasps are usually less useful than other terrestrials but will occasionally catch a trout’s eye.

“Back in my guiding days, I would pump one fish’s stomach each day during the summer just to keep track of what was happening or changing and what might be on the menu for the day, and pretty much each day I found a single yellow jacket/paper wasp/mud dauber/winged stinged critter in the belly of nearly every trout,” Fly Fisherman columnist Charlie Craven said.

Ants, beetles, bees, and other terrestrials however, don’t typically have big population spikes from year to year like Mormon crickets and hoppers, which isn’t a bad thing. Places where hopper outbreaks are less common, like the Eastern U.S., are great places to fish these other terrestrials.

2023 Western United States Hopper Forecast

According to the Rocky Mountain Grasshopper Forecast (a collaborative effort between the USDA Forest Service, the University of Wyoming, and the Colorado State University Extension Office), there is a moderate risk of a grasshopper outbreak in the Rocky Mountain West in 2023.

The Western Ag Network’s crystal ball foretells that another “good” (which is of course “bad” and “destructive” for farmers and ranchers) hopper-fishing year is in store for Montana.

"It still looks like we have a pretty significant amount of grasshoppers throughout Montana," said Gary Adams, U.S. Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) State Plant Health Director for Montana. "It kind of moves around where they're bad. A few years ago, they were in different places and some places it's the same. I would say that there is a significant potential for there to be continued grasshopper populations in 2023."

A map of the western U.S. showing predicted grasshopper densities for 2023. — Areas marked by red, orange, and green should be in for at least some hopper fishing this year. (Courtesy of the U.S. Department of Agriculture, Animal and Plant Health Inspection Service)

In Idaho, the state Department of Agriculture has seen requests for assistance for grasshopper and Mormon cricket control from farmers and ranchers increase by 62 percent from 2022, according to an Idaho Falls Local News 8 article. This largely applies to the arid Snake River basin and dry areas along the Montana border.

Certain sections of the high-desert regions of eastern Oregon and Washington can also likely expect productive hopper fishing.

This past March, the Wyoming Livestock Roundup stated, “…USDA APHIS indicates there will be about five or six small areas with high densities of grasshoppers they’ll focus on this spring. This includes Uinta, Sublette, Carbon, Converse, Natrona and Johnson counties.” Check out the Upper Green and North Platte River drainages for productive fishing.

In Utah’s trout country, experts are predicting a normal but delayed hopper season due to the area’s cool spring.

The Denver Gazette’s OutThere Colorado publication, however, has predicted a relatively quiet hopper season for much of the Centennial State. The Rangeland Grasshopper Hazard Survey for 2023 has concluded that: “The risk for grasshopper outbreaks will be low for much of Colorado this summer, save some regions of Routt County where the U.S. Department of Agriculture's Animal and Plant Health Inspection Service (APHIS) has forecasted 15-plus grasshoppers to be present per square yard of outdoor space.”

A map of Colorado showing predicting grasshopper densities for 2023. — The Yampa River drainage is projected to have some of Colorado's best hopper fishing this year. (Courtesy of the U.S. Department of Agriculture, Forest Service)

Routt County includes the Yampa River watershed.

California’s Sacramento region remains stuck in drought, which means there could be plenty of hopper opportunities in trout and bass fisheries there. The Tahoe area might not be poised for as much of a banner year with its big winter.

The American West is looking to continue its trend of above-average hopper-fishing seasons.

2023 Western Canada Hopper Forecast

Canada’s Prairie Pest Monitoring Network hasn’t put a ton of emphasis on the risk of grasshoppers for 2023. In areas of Alberta and Saskatchewan, however, there is hope for a good year.

“After evaluating 14 years of grasshopper data, a trend has emerged that one species (Melanoplus bruneri, Bruner’s spur-throat grasshopper) in the Peace and northern crop-production areas seems to have a two-year lifecycle,” according to the webpage. “On the Alberta side of the Peace, a pattern of odd years with grasshopper numbers that can cause crop loss issues, while in the even years the numbers are low. If the pattern holds true, then Bruner’s grasshopper could be an issue in the Peace and the northern crop production areas in 2023.”

Regarding southern Alberta: “There is potential for outbreaks in the southern region and along the eastern border region in 2023.” Forecasting maps created by government agency Agriculture and Agri-Food Canada suggest that the Old Man and Bow rivers are also poised for an exciting August and September for fly anglers.

Parts of Saskatchewan could also see hoppers: “The long, dry, warm late summer and fall (of 2022) in many parts of the province meant good conditions for grasshopper egg laying,” according to Saskatchewan.ca. “This means that we anticipate continued pressure from grasshoppers in many regions in 2023.” Try the South Saskatchewan River tailwater or Lake Diefenbaker for consistent hopper fishing this year.

2023 Worldwide Hopper Forecast

While it’s a bit early to know for sure, it looks as though New Zealand is poised to deliver good terrestrial fishing in the spring of 2024. The country's well-preserved habitats, coupled with favorable weather conditions, promise bountiful hopper populations and big fish.

Drought conditions have improved in South America in 2023, so spring 2024’s hopper fishing might not be as good as it’s been for the past few years. There are not formal pest forecasting services in this area.

European countries like England, Ireland, and Scotland, can offer excellent hopper fishing opportunities and have witnessed a resurgence in hopper fishing interest in recent years. Conservation efforts aimed at preserving grasslands and favorable weather conditions indicate a rise in hopper populations.

A nice brown trout with a hopper fly in its mouth being held by two hands just above the water. — Hopper season holds promise for fishermen seeking some of the most exciting fishing of the year, but keep your thermometer wet. (Ross Purnell photo)

Hopper Fly Recipes

(click the fly names for the full tutorials)

Paramore's Thunder Thighs

HOOK: #8-14 Tiemco 5262.
THREAD: 8/0 Veevus or 3/0 Danville monocord.
BODY: Two alternate color sheets of 2mm Fly Foam, glued together and cut with round-end Chernobyl Cutter.
WING: White polypropylene macramé yarn.
EYES: Black 2mm Fly Foam.
LEGS: Sliver of bicolor foam from body for the thighs, and small barred Montana Fly company Sexi-Floss from the knee down.
FRONT LEGS: Small barred Sexi-Floss.
COLLAR: Dubbing to match foam color.

Amy's Ant

HOOK: #6-12 Tiemco 5262 or 5263.
THREAD: Brown or tan 3/0 Monocord.
UNDERBODY: 2mm tan Fly Foam.
OVERBODY: 2mm Tan, Rust, or purple Fly Foam.
LEGS: Medium brown round rubber legs.
HACKLE: Brown rooster neck or saddle, trimmed short.
BODY: Olive Krystal Chenille.
UNDERWING: Rainbow Krystal Flash.
OVERWING: Cow or yearling elk hair.
THORAX: Bronze Arizona Synthetic Peacock dubbing.

Craven's Fat Angie

HOOK: Daiichi 1167 #12-20.
THREAD: Veevus 14/0 Red.
BODY: 3mm Black Foam.
ABDOMEN: Mahogany Superfine Dubbing.
LEGS: Black Super Floss.
WINGS: Polypropylene Macramé Yarn, smoke, rust, and gold mixed, topped with UV Blue Ripple Ice Fiber.
INDICATOR: Pink Razor Foam.
HACKLE: Brown Rooster Neck or Saddle.
THORAX: Mahogany Superfine Dubbing.

Chernobyl Ant

HOOK: TMC 5263 #4-12
THREAD: 3/0 Monocord, black
BACK: 3mm Black Foam and 2 mm Yellow Foam
LEGS: Medium Round Rubber Legs
HACKLE: Brown rooster saddle
UNDERBODY: Olive Krystal Chenille

Chubby Chernobyl Elevated

HOOK: #4-8 Tiemco 5262 or #10-14 Umpqua XT050.
THREAD: Tan 6/0 UNI-Thread.
BODY: Nature’s Spirit Emergence Dubbing, Hare’s Ear.
OVERBODY: Black over tan 3mm Wapsi Fly Foam.
LEGS: Gold/amber black Hareline Fly Enhancer Legs
WINGS: Polypropylene Macramé Yarn, gray, brown, rust, gold, and tan, brushed and blended together.

Grillos's User Friendly

HOOK: #12-16 Tiemco 100.
THREAD: Black Veevus 14/0.
TAIL: Medium dun Mayfly Tails.
BACK: Black 1 mm Wapsi Razor Foam.
ABDOMEN: Purple Hareline Micro Fine Dry Fly Dub.
WING: Gray McFlylon.
LEGS: White, fine round rubber, barred with a Sharpie marker.
HACKLE: Grizzly rooster.
THORAX: UV Purple Ice Dub.

Letort Hopper

HOOK: TMC 100SP-BL #10-16
THREAD: Yellow 3/0 Monocord
ABDOMEN: Pale Yellow Dubbing
WING: Turkey Wing Fibers, coated with vinyl cement
COLLAR AND HEAD: Natural Deer hair

Foam Beetle

HOOK: TMC 100Sp-BL #10-20
THREAD: Back 6/0
SHELLBACK: Black Fly Foam
LEGS: Moose Hair
BODY: Peacock Herl
INDICATOR: Orange Fly Foam

Lucky B Wasp

HOOK: #16 Tiemco 2487.
THREAD: Yellow 8/0 UNI-Thread.
ABDOMEN BASE: Yellow macramé yarn.
ATTACHMENT: 0X nylon monofilament.
ABDOMEN: Strip of yellow Fly Foam, 1mm X 3mm.
LEGS: Small, amber Sexi-Floss.
SHELLBACK: Strip of yellow Fly Foam, 2mm X 3mm.
THORAX: Black Superfine Dubbing.
WINGS: Mixed yellow, rust, black, and smoke gray polypropylene macramé yarn.
COLLAR: Black Copic Marker.

Tying Tips to create your own hopper pattern: https://www.flyfisherman.com/editorial/fly-fishing-with-foam-terrestrials/152216

This upcoming hopper season holds promise for fishermen seeking to embrace some of the most exciting fishing of the year. Go fish, but plan on short days and keep your thermometer wet. Before you know it, it’ll be streamer time.

Joshua Bergan is Fly Fisherman’s digital editor and lives in southwest Montana.