Midge / EmergersBiot Midge

The Biot Midge is a simple but effective pattern that imitates a midge pupa. The brown goose biot body creates a realistic segmented appearance, and the black India hen back collar adds a lifelike, buggy silhouette in the water.

Season
Spring, Summer, Fall
Difficulty
Beginner
Target Species
Trout
Updated
Apr 2025
Biot Midge fly pattern - imitates Midges tied for Trout

Overview

Tied with a slim, segmented body of brown goose biot for a realistic ribbed look, this midge pattern is finished with a sparse black dubbed thorax and a soft India hen back collar-sometimes with a small bead added for extra weight. It excels in clear water where trout are keying on small, emerging midges.

Where to Buy This Fly

We only link to fly shops we trust. Some links are referral links, which may earn us a commission at no extra cost to you.

Materials

Hook:
#18-22 Tiemco 100
Thread:
Black UTC 70
Body:
Brown Goose Biot
Thorax:
Black Superfine Dubbing
Collar:
Black India Hen Back

Behavior & Presentation

Natural Behavior: As gas accumulates in the thorax, pupae ascend vertically toward the surface film where they hang suspended during their vulnerable transformation, creating extended feeding opportunities throughout the day.

Where Trout Eat It: Fish intercept ascending pupae at multiple depths in lakes and rivers, particularly near weed beds, structure, and calm current seams.

How to Fish It: Suspend in the film on a dead drift, allowing the pattern to hang motionless as trapped emergers do naturally during their protracted emergence.

Best Water: Most productive in foam lines, slicks, pools, and current seams where pupae concentrate during their film-hanging phase.

Strike Type: Subtle surface sips or barely perceptible indicator movement as fish confidently take suspended emergers.

Fishing Strategy

Rigging Suggestions: Use a light tippet and a long leader for a delicate presentation.

Seasonal Timing: When trout are feeding on midges, particularly during a midge hatch.

Pro Tips: This fly is small and can be difficult to see, but the white CDC wing can help with visibility. It should be fished in or just below the surface film.

Entomology

Midge pupae exhibit a distinctive ascending behavior as gas bubbles accumulate in their thorax, causing them to rise slowly through the water column toward the surface film where they will emerge as adults. This vertical movement occurs throughout the day and night, with concentrations often highest during dawn and dusk transitions. Fish focus intensely on emerging midges because the slow, predictable ascent and surface-hanging vulnerability create extended feeding opportunities requiring minimal energy expenditure.

Order
Diptera
Family
Chironomidae
Common Name
Midge
Organism Type
insect
Life Stage
general

Pattern Characteristics

Beginner Difficulty
Trout
Stillwater
Moving Water
Spring
Summer
Fall
Imitates: Midges
Worldwide
dead-drift
midge-hatch
beginner-friendly
low-clear-water