Midge Fly: All You Need to Know for Effective Control and Prevention

Midge flies, often mistaken for mosquitoes, are small, dainty insects that offer several environmental benefits. These true flies, belonging to the Chironomidae family, possess only one pair of wings, long skinny legs, and are relatively soft-bodied. Although they resemble mosquitoes, midges do not bite humans and are typically found near water sources like streams, lakes, and rivers, mating and laying their eggs in these environments.

An essential element in the food chain, midge flies serve as a food source for fish and aquatic insects. Some species can even indicate the presence of excessive organic matter in bodies of water, which suggests potential pollution issues. In contrast to mosquitoes, midges hold their first pair of legs forward and upward while resting, making it simpler to differentiate between the two.

Midge Fly Basics

Characteristics

Midge flies, also known as midges or non-biting midges, belong to the family Chironomidae within the order Diptera. These insects resemble mosquitoes but do not bite humans. They have a short proboscis and are soft-bodied, with a size range of 1/32 to 1 3/8 inch in length¹.

Midges have long legs and varying antennae – feathered in females and bushy in males². While at rest, midges tend to hold their first pair of legs forward and upward³.

Diversity of Species

There are a diverse range of midge fly species⁴. Some examples include:

• Chironomus riparius: A common species found in North America, often used in ecological studies.
• Polypedilum vanderplanki: Found in Africa, this species can survive extreme dehydration.

Life Cycle of Midge Flies

Larvae

Midge flies, like many other insects, undergo a complete metamorphosis during their life cycle, starting with the larval stage. Eggs laid by adult females hatch into larvae, which live in aquatic habitats and feed on organic matter. The larvae are usually found at the bottom of water bodies, within the muck:

• Size: Small, around 1-4mm long
• Color: Often red or green; sometimes transparent
• Shape: Worm-like, with distinct segments

The larval stage lasts around 3 days to a week, with the midge larva molting several times as it grows.

Pupae

After they have fully developed, midge larvae transform into pupae. The pupal stage serves as a transitional phase between the larva and adult stages:

• Location: Near the surface of the water
• Duration: Approximately 1 to 4 days
• Characteristics: Inactive and non-feeding

During this stage, the midge develops its adult features within a protective case.

Adults

As the pupal stage comes to an end, adult midge flies emerge from the water and take flight. The adult midge flies have several distinguishable traits:

• Size: Small, with a wingspan around 2-4mm
• Wings: One pair, long and narrow
• Legs: Long, skinny legs, often held forward and upward
• Antennae: Males often possess feathery antennae for sensing female wing sounds

As adults, midge flies do not bite, despite their preference for organic matter. Adult midges mate, and females then lay thousands of eggs, marking a new beginning for the midge fly life cycle.

Midge Fly Habitat

Freshwater Environments

Midge flies, particularly those in the family Chironomidae, are commonly found in freshwater environments like ponds, streams, lakes, and rivers. They thrive in these habitats due to the ample food supply and optimal conditions for reproduction. For example, midge flies are frequently seen around lakes in North America.

• Habitat features:
  • Freshwater sources
  • Abundant food supply
  • Ideal conditions for reproduction

Seasonal Changes

Midge fly populations tend to increase during specific times of the year, influenced by factors such as temperature and water availability. In North America, midge fly populations often rise during the winter months. As temperatures drop, the water temperature in lakes, ponds, and rivers can become more stable, providing a suitable environment for midge larvae to develop.

• Characteristics of midge fly populations in winter:
  • More stable water temperatures
  • Enhanced larval development
  • Increased population sizes

Comparison of Midge Fly Populations in Winter and Summer

Midge flies adapt well to various environmental conditions, allowing them to be successful in many freshwater habitats and through seasonal changes. Understanding their habitat preferences and population trends can help manage these insects more effectively.

Fly Fishing for Midge Flies

Midge Fly Patterns

Midge flies are diverse, and their patterns vary. Some popular midge fly patterns include:

• Midge Larva: Imitates the larval stage of midges and is usually a small, slender fly.
• Midge Pupa: Resembles the pupal stage, often incorporating a small bead to represent the emerging insect.
• Midge Nymph: Mimics the juvenile stage of certain midge species and can include elements like a thin body and flashy accents.

In order to “match the hatch,” use fly patterns that imitate what the fish are feeding on at the time. Some common midge patterns include midges (small, sinking flies), dry flies (small to medium floating flies), and streamers (larger, heavier flies).

Techniques and Tips

• Indicator Fishing: Use a strike indicator (e.g., a small foam float) on your leader to detect subtle takes.
• High Sticking: Keep your rod high and minimize slack line to feel the strike and maintain control.
• Long Leaders: Opt for a longer leader length to help the fly sink and provide a more natural drift.
• Thin Tippets: Choose a thin tippet material to reduce visibility, as midges are small and trout can be wary.

Example: A popular method for midge fly fishing is using a tandem rig, where a midge larva is fished as the bottom fly, and a midge pupa or emerger is fished as the top fly.

Essential Gear

Key items for midge fly fishing include:

Remember, midge fly fishing can require precision and patience, but the rewards are well worth the effort when you hook into a beautiful trout or other fish.

Midge Fly Imitations

Popular Patterns

Midge flies are a vital food source for fish, and many fly patterns imitate these small insects to attract fish. Some popular midge fly patterns include:

• Zebra Midge: A simple and effective pattern that imitates midge larvae and pupae, often tied with a slender body and ribbed with wire.
• Griffith’s Gnats: A classic dry fly pattern that imitates adult midges, featuring a peacock herl body and hackle for the wings and legs.
• Rainbow Warrior: A flashy nymph pattern with a colorful bead and flashabou thorax to attract fish, great for fishing in both clear and off-color water.
• Top Secret Midge: Designed by Pat Dorsey, this pattern imitates emerging midges with a slim body and segmented thorax.

Tying Techniques

Midge fly imitations can be created using various tying techniques, each focusing on specific parts of the pattern:

• Dubbing: A method for creating the body of the fly, using materials like peacock herl, thread, or synthetic dubbing. A slender, tapered body is crucial for midge imitations.
• Ribbing: Adding contrasting material like wire or tinsel to the fly’s body to create segmentation. Zebra midges often use silver or colored ribbing.
• Wings and Legs: Small fibers or hackle can be used to imitate wings and legs, adding lifelike movement to the pattern. Griffith’s gnats utilize hackle to imply wings and legs.
• Beads and Flash: Incorporating bead heads or flashy materials like flashabou can help attract fish, especially in nymph patterns like the Rainbow Warrior and Disco Midge.

Midge fly patterns can be fished year-round, as midges are present in various life stages throughout the year. Adapting your pattern and presentation to match the local hatch or conditions will increase your chances of success. Remember to keep these imitations small, as midges are a favorite food source for many fish species due to their size.

Midge Fly Predators and Prey

Natural Predators

Midge flies have several natural predators, including:

• Fish (e.g., trout)
• Birds
• Other insects (such as dragonflies)

One trait making midge larvae resilient is their ability to secure oxygen in low dissolved oxygen environments using hemoglobin. This ability limits the number of predators that can survive alongside them.

Prey Items for Fish

Midge flies, especially their larvae (also known as bloodworms), are an essential part of many freshwater fish diets, including trout. They serve as a rich source of protein, making them a crucial aspect for anglers and fish enthusiasts alike.

Overall, midge flies and their larvae play an essential role in aquatic ecosystems, impacting predator and prey relationships among fish and other species.

Midge Fly Control

Natural Methods

• Predators: Encourage natural midge predators like birds, fish, and dragonflies to the area.
  • Example: Installing birdhouses or bat boxes can help attract predators that feast on midges.
• Water circulation: Increase water circulation in ponds or lakes to disrupt midge breeding.
  • Example: Installing fountains or aerators can help prevent midge larvae from thriving.

Artificial Methods

• Insecticides: Apply biological insecticides to affected bodies of water.
  • Pros:
    • Effective in reducing midge populations
    • Can target specific species
  • Cons:
    • May not provide long-term control
    • Can impact non-target species
• Traps: Use light traps or bug zappers to attract and eliminate adult midges.
  • Pros:
    • Can quickly reduce the number of adult midges
    • Non-toxic and chemical-free
  • Cons:
    • May not effectively control breeding populations
    • Can also kill beneficial insects

Midges come in various colors such as red, black, and brown. They are distinguishable by the antennae of the males, which are often feathery or bushy. They are commonly found in bodies of water and can form swarms or clusters. Midge fly control is essential to prevent large swarms from becoming a nuisance, especially in areas near the west and south Platte River.