The beetle is a terrestrial fly pattern for fishing trout during warm summer months when aquatic insect activity subsides and terrestrial insect activity peaks. The most popular imitation fly pattern is the foam beetle with rubber legs shown in the image below.
Beetle patterns are used primarily for targeting riverine trout in high elevation, cold water streams of the Rocky Mountains, but can also be used for fishing stillwater trout. During the driest times of year—toward the beginning of July—fly hatches begin to dwindle and terrestrials take center stage through autumn frost in October.
During this time, beetle activity is at its highest and they can be found along the edges of the many streams and slow-moving meadow waters that zig zag the Rocky Mountain range. Fishing a beetle imitation along the shaded vegetation laden edges of streams when hatch activity is sparse is a sure fire method for luring opportunistic trout to the surface.
The black beetle is by far the most common beetle imitation found in fly boxes, but beetles come in variety of colors and patterns. The most popular beetle imitations include the traditional Foam Beetle, Black CDC Beetle, Jakes Gulp Beetle and Brown CDC Beetle. Beetle patterns also represent a range of bugs that end on the menu including shield bugs, june bugs, weevils and ticks. The coch-y-bonddu fly is another beetle type imitation worth experimenting with.
Fly size recommendations
With such a wide variety of beetle species, you really want to maintain a range of beetle styles and sizes in your arsenal. As a rule of thumb, stick with small fly sizes (#14-16) for river trout and larger fly patterns (#10-14) when fishing for stillwater trout. That being said, you should also be open to experimenting. If larger beetles aren’t getting the bite—or vice versa—test out smaller flies.
Matching a specific beetle species is not nearly as important as matching size. You can experiment with different patterns, but you’ll want to try and match your fly size as closely as possible to the native beetle population.
Tips for fishing beetle flies
When fishing foam patterns, we recommend starting out by fishing your beetle fly without the floatant. This will cause the fly to sit lower on the surface. A beetle imitation that sits lower, even partially submerged, tends to attract more attention from trout than a beetle on the surface. Trout recognize that a submerged beetle is a helpless beetle and feel more secure to feed subsurface.
Terrestrials—including beetles—tend to congregate around the bushy parts of rivers and lakes. This is also where you’ll often find trout laying in wait just below the surface ready to gobble up the wayward beetle that has the misfortune of going for a swim.
Wind is your friend and can be the best indicator or where you’ll find trout on a lake. Wind can displace terrestrials and create artificial “hatches” of beetles forced from the air and banks into the water. Fish with the wind at your back and target corners of lakes and stream banks where windswept insects are likely to accumulate.
Rain offers anglers another good opportunity to catch trout using beetle patterns—especially in rivers. Large rain storms can create a slip-and-slide effect that washes beetles and terrestrials into the water. Fishing beetle patterns (floating or subsurface) along the bank immediately following a rainstorm is an effective strategy for targeting feeding trout.
There is nothing graceful about a beetle hitting the water. Cast your beetle fly so it produces an audible plop, followed by a few twists and strips that mimic a struggling insect.
