{
  "url": "https://theflybench.com/patterns/mercury-brassie",
  "id": "cm3jr8gz1wq9iplpgc4u7dphgw",
  "title": "Mercury Brassie",
  "slug": "mercury-brassie",
  "description": "The Mercury Brassie is a variation of the classic Brassie developed on Colorado's South Platte River in the 1960s. A silver-lined glass bead replaces the traditional metal bead, imitating the gas bubble effect of an emerging midge pupa. The weighted wire body sinks quickly, making it ideal for dry-dropper rigs.",
  "imitates": "Midge Pupae",
  "patternCategory": "midge-emerger",
  "difficulty": "Beginner",
  "variantOf": "bead-head-brassie",
  "targetSpecies": "Trout",
  "waterTypes": [
    "Moving Water"
  ],
  "seasons": [
    "Year Round"
  ],
  "materials": "**Hook**: Tiemco 101, #16–#22\n**Bead**: Silver-lined glass bead, extra small\n**Thread**: Black UTC 70 Denier\n**Abdomen**: UTC Ultra Wire, copper\n**Thorax**: Peacock herl",
  "images": [
    {
      "url": "/images/patterns/midge-emerger/mercury-brassie.webp",
      "source": "The Fly Bench"
    }
  ],
  "videos": [
    {
      "url": "https://youtu.be/BqhZnlYposo?si=MaN5aULwD0wOpE-K",
      "label": "San Juan River Flies"
    }
  ],
  "createdAt": "2025-12-01T05:00:00.000Z",
  "updatedAt": "2025-12-07T13:40:51.734Z",
  "regions": [
    "Rocky Mountain"
  ],
  "waters": [
    "South Platte River"
  ],
  "tags": [
    "dead-drift",
    "midge-hatch",
    "classic",
    "beginner-friendly",
    "low-clear-water",
    "tailwater",
    "spring-creek"
  ],
  "essential": false,
  "tier": "",
  "entomology": {
    "order": "Diptera",
    "family": "Chironomidae",
    "commonName": "Midge",
    "organismType": "insect",
    "lifeStage": "pupa",
    "behavior": "Midge pupae drift suspended in the water column while accumulating gas beneath their pupal casings, maintaining neutral buoyancy as they prepare for emergence. Trout selectively feed on these mid-water pupae during their prolonged pre-emergence drift, capitalizing on year-round availability and the extreme vulnerability of immobile transforming insects."
  },
  "relatedPatterns": [
    {
      "slug": "bead-head-brassie",
      "type": "variant"
    },
    {
      "slug": "adams-fly",
      "type": "same-hatch"
    },
    {
      "slug": "griffith-s-gnat",
      "type": "same-hatch"
    },
    {
      "slug": "hatching-midge",
      "type": "same-hatch"
    },
    {
      "slug": "poly-wing-midge",
      "type": "same-hatch"
    },
    {
      "slug": "no-see-um",
      "type": "same-hatch"
    },
    {
      "slug": "biot-midge-pupa",
      "type": "alternative"
    },
    {
      "slug": "glo-brite-miracle-midge",
      "type": "alternative"
    }
  ],
  "behaviorPresentation": "**Natural Behavior**: Ascending pupae hang vertically in the current with gas bubbles trapped beneath their shuck, creating a distinctive profile as they transition toward the surface. Fish key on this mid-column drift stage year-round because the suspended pupae cannot escape and remain available for extended periods.\n**Where Trout Eat It**: Trout sip these throughout the water column from 6 inches to 4 feet deep, especially in tail-outs, seams, and along foam lines where drift concentrates.\n**How to Fish It**: Dead drift the pattern deep through runs using tight-line contact, allowing natural tumbling motion to match helpless ascending insects.\n**Best Water**: Target seams where current speed changes, tail-outs with consistent flow, and foam lines that concentrate emergers.\n**Strike Type**: Subtle hesitation or slight tightening of the line signals fish intercepting mid-column drift.",
  "fishingStrategy": "**Rigging Suggestions**: Fish on 5X–6X fluorocarbon, 18–24 inches below an indicator or dry fly. Effective droppers include Mercury Pheasant Tails, RS2s, Barr Emergers, and Top Secret Midges in sizes #18–#22.\n**Seasonal Timing**: Year round, with peak effectiveness during winter and early spring midge hatches.\n**Pro Tips**: The weighted wire body sinks quickly to the feeding zone. The silver-lined bead catches light and creates flash, drawing attention from feeding trout.",
  "overview": "The Mercury Brassie builds on Gene Lynch's original Brassie pattern with one key modification: the silver-lined glass bead creates a subtle air bubble effect that mimics midges preparing to emerge. Popular color variations include copper, red, chartreuse, green, and black to match different midge species. The simplicity of this three-material pattern makes it quick to tie and extremely durable."
}