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Technical reviewed side profile illustration of Mercury Midge showing translucent glass bead, slim thread body, fine wire rib, optional compact thoraxIllustrated reference

Nymph · guide 29

Mercury Midge

Pat Dorsey's glass-bead midge pattern with a slim thread body and fine wire rib.

Common size
#18–24
Common colors
cream and copper, olive and copper, black and silver
Imitates
midge pupa, small subsurface midge
How to recognize it

A translucent pearl glass bead, narrow thread abdomen, and fine wire rib are signature features. Body and rib colors vary, so every visible combination remains labeled.

Technical reviewed side profile illustration of Mercury Midge showing translucent glass bead, slim thread body, fine wire rib, optional compact thorax
Illustrated reference

Mercury Midge reviewed side profile

A schematic profile emphasizing translucent glass bead and slim thread body.

View
reviewed side profile
Color shown
cream body, copper rib, pearl glass bead
Look for
translucent glass bead; slim thread body; fine wire rib; optional compact thorax
Open full-size image ↗

On the water

Know when and how to fish it.

Use these tips as a starting point. The river, depth, insects, and fish behavior still decide the final presentation.

01

When to use it

  • As a subsurface midge in cold or clear water.
  • Alone or as a small dropper.
02

How to fish it

  • Dead-drift at the feeding depth.
  • Keep the rig light enough for the lane.
03

Mistakes to avoid

  • Confusing a metal-bead Zebra Midge with the glass-bead Mercury Midge.
  • Hiding body color when labeling a variant.

Common variations

Small changes can make a different fly.

Three reviewed technical illustrations show the identifying profile, construction, and fishing orientation. They are schematic field-guide aids, not photographs.

Reviewed core form

A translucent pearl glass bead, narrow thread abdomen, and fine wire rib are signature features. Body and rib colors vary, so every visible combination remains labeled.
Colors shown
cream and copper, olive and copper, black and silver
Weighting
Weighting is identified when it defines the reviewed form; other bead or weight choices remain labeled variants.

Related patterns

Black Beauty Midge ↗Zebra Midge ↗Top Secret Midge ↗

How this guide was checked

Fly information and photo sources.

Guide checked on 2026-07-12. Every image has its own source and usage record. Natural insects and hand-tied flies can vary in shape and proportion.

Pattern sources

Orvis NewsHow to Tie a Mercury Midge↗

Image credits