anabrus simplex

Anabrus simplex
Anabrus simplex

Guest Blogger: Mike Cline, Boseman, MT

It’s 1848, in the early days of the settlement of Salt Lake City by the Mormons. Hordes of Anabrus simplex are devastating their first spring crops. In what became known at the “Miracle of the Gulls”, the plague of Anabrus simplex was wiped out and the crops saved. More importantly for the fly angler, Anabrus simplex, a very large insect, gained the name of Mormon Cricket. (It wasn’t actually named taxonomically until 1852). The Mormon Cricket isn’t actually a cricket but instead a flightless shield-back Katydid. As trout or smallmouth food they are a minor terrestrial species, but where they are found in conjunction with Western rivers, imitations of the Mormon Cricket can be very productive. Although not typically found in densities that grasshoppers are found, the Mormon Cricket is found throughout western North America in rangelands dominated by sagebrush and forbs. Medium to large rivers that traverse large expanses of sagebrush are prime opportunities to fish Mormon Cricket imitations. Occasionally, Mormon Crickets will form large swarms of 1000s of insects that are always on the move, up to 2 miles a day. When these swarms occur near rivers, many individuals fall prey to trout.

It's a big bug!
It’s a big bug!

The first thing you notice about Mormon Crickets is their size. They are large and two-inch long specimens are routine. I encounter them most often in the middle of summer on warm sunny days walking through expanses of blooming sagebrush. In the heat of the day, they will crawl to the top of the plant to feed on the yellow blossoms of the sagebrush. Their dark brown color and size make them very visible from many yards away as black dots against yellow-green backgrounds.

Mormon Cricket Territory
Mormon Cricket Territory

However, they are wary and difficult to approach and capture as they will drop into the bowels of the plant at any sign of movement toward them. My favorite locations for finding them are on the sagebrush flats around the Lamar and Gardiner Rivers in Yellowstone. On warm August days they are relatively easy to find. Another location is along the northern shoreline of the Madison River known as Grasshopper bank. Lined with sagebrush, this mile-long section of the Madison has sagebrush right up to the edge of the river and Mormon crickets are not an uncommon sight on warm summer days.

Hopper Version
Hopper Version

One might think that a flightless cricket the size of a Mormon Cricket wouldn’t find its way into the river, but they do somehow, and trout don’t miss an opportunity to feed on them when they do. From my reading and my personal experiences, size and color are the most important aspects of imitating this terrestrial insect. Although they do occur in a variety of colors, the most predominate in my experience is a dark brown or black with little if any areas of high contrast. There is one certainty, their bodies are big and fat. Imitating a Mormon Cricket results in a very large fly.

I have two versions that I take to the river mid-summer. One is really just a larger version of the Easy as Cherry Pie hopper. The other is a variation on Walter Wiese’s Prom Queen. The hopper variation uses the large Beavertail shape from River Road Creations, black or brown foam and the usual dark underbody, legs and wing. Adding a normal deer hair wing is not really true to the imitation of the insect as they are flightless and have no wings. More recent variations used stubby wings instead. The Mormon Prom Queen is tied essentially the same as the original, except with different colors and proportions. Instead of using yarn for the furled body, I use two shades of dark brown/black large chenille. One of the colors usually has some sparkle to it. The wing on the Mormon Prom Queen is doubled back to create some bulk and the impression of the stubby shield back on the natural.

Mormon Prom Queen
Mormon prom Queen

Fishing the Mormon Cricket isn’t any different from fishing hopper patterns, although their size does demand either stiffening or shortening your leaders a bit to maintain accuracy. When treated with a bit of silicone floatant, these flies ride high and bob around like the living insect struggling to get out of the water. If you find yourself along Western rivers in sagebrush country during a warm summer day, you are likely to see a few Mormon Crickets. If you do, you’ll be glad you tied a few up and have them stashed away in you fly box. Anabrus simplex may not be the most famous fly around, but trout and smallmouth love them.


  1. Floated the Green River below Flaming Gorge UT this summer. Encoutered hundreds of these crickets roaming our riverside campsight. We threw them loose to the trout for hours….every single one of the dozens and dozens we threw was absolutely hammered by trout of all sizes as soon as they hit the water. It was absolutely unbelievable.

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