Midges

What Do Midges Look Like?

Midges are small, delicate-looking flies that can easily be mistaken for mosquitoes, though they don’t bite in most cases. Their appearance varies slightly depending on the type (biting vs. non-biting), but generally, they share these characteristics:

• Size: Very small, usually 1–4 mm in length. Some species can appear slightly larger, up to 6 mm, but they’re still much smaller than typical houseflies.
• Body: Slender, elongated bodies. Color ranges from pale gray or brown to black. Non-biting midges often have a fuzzy or hairy appearance due to fine bristles on their bodies and legs.
• Wings: Clear or slightly smoky, held flat over the body when at rest. Non-biting midges often hold their wings vertically over their body in a characteristic V-shape.
• Legs and Antennae: Long, thin legs that can give them a fragile, spindly look. Antennae are typically long and feathery in males, shorter and less noticeable in females.
• Behavior Clues: Often swarm in large numbers near water sources at dusk or dawn. Unlike mosquitoes, non-biting midges do not feed on blood; males generally feed on nectar.

If you see tiny, mosquito-like insects swarming near water but they aren’t biting, they are most likely non-biting midges.

Where Are Midges Found?

Midges are highly associated with moist environments, especially areas near water. Where you find them depends on the species, but here are their most common habitats:

• Near Standing or Slow-Moving Water: Lakes, ponds, rivers, streams, marshes, and wetlands are prime breeding grounds. Many midge larvae develop underwater or in saturated soil at the water’s edge. Even small puddles or drainage ditches can support breeding.
• Damp Soil and Decaying Organic Matter: Muddy riverbanks, compost piles, or areas with decaying plant material can harbor larvae. Moist garden soil or areas with poor drainage can attract midges, especially in residential landscapes.
• Vegetation and Shaded Areas: Adults often rest on grasses, shrubs, and trees near water. They may also swarm around tall vegetation in parks, backyards, or wetlands.
• Near Artificial Water Sources: Ornamental ponds, fountains, birdbaths, or poorly maintained gutters can be breeding sites. Irrigation runoff, puddles from sprinklers, or flooded lawns can also support larvae development.
• Seasonal and Time-of-Day Patterns: Midges are most noticeable in spring and summer, when temperatures are warm and water is abundant. Swarming typically occurs around dusk and dawn, which is when adults mate in large groups.

You’re most likely to find midges in areas where there’s moisture, stagnant water, or decaying plant material, and they tend to concentrate near the source rather than dispersing far from breeding sites.

What Do Midges Eat?

Midges have different feeding habits depending on the species, but generally, their diet is tied to their life stage (larvae vs. adult) and whether they are biting or non-biting midges:

Larval Stage:

• Non-biting midge larvae: Feed on detritus—decaying plant material, algae, microorganisms, and organic matter in the water or soil. They play an important role in aquatic ecosystems by recycling nutrients.
• Biting midge larvae: Also feed on organic matter and small microorganisms in wet soil or aquatic environments, though adult females are the ones that bite.

Adult Stage:

• Non-biting adult midges: Feed primarily on nectar, plant sap, or other sugar sources. They do not bite and pose no direct threat to humans or animals.
• Biting adult midges (Ceratopogonidae family, often called “no-see-ums”): Females feed on blood from mammals, birds, or reptiles, which they need for egg production. Males feed on nectar or plant juices and do not bite.

Adult midges generally have short lifespans (a few days to a few weeks), so their feeding is primarily focused on reproduction. Because larvae feed on organic matter in water, controlling breeding sites—like standing water and decaying vegetation—is key to limiting populations.

Midge Life Cycle

The life cycle of midges is relatively short and depends on the species, but most follow a four-stage development pattern typical of flies: egg → larva → pupa → adult:

• Egg Stage: Female midges lay eggs in moist environments, usually in water, wet soil, or decaying organic matter near water sources. Eggs are often laid in clusters or gelatinous masses that attach to surfaces in water or mud. Depending on temperature and moisture, eggs hatch within a few days to a week.
• Larval Stage: This is the feeding stage of the midge. Larvae are worm-like and live in water, mud, or damp soil, feeding on algae, microorganisms, or decaying organic material. Larval development can last from 1–4 weeks depending on environmental conditions such as temperature, moisture, and food availability. Some species have specialized larvae adapted to flowing water, stagnant water, or specific organic substrates.
• Pupal Stage: After the larval stage, midges enter the pupal stage, which is a non-feeding, transitional phase. Pupae are often found near the water surface or in moist soil, depending on species. This stage usually lasts a few days, during which the organism transforms into an adult.
• Adult Stage: Adults emerge from the pupae and are primarily concerned with mating and reproduction. Non-biting midges feed on nectar or plant juices; males often form large swarms to attract females. For biting midges, females seek blood meals to produce eggs; males feed on nectar. Adult midges generally live from a few days to a few weeks, with the lifespan of swarming adults often being very short.

Because larvae live in water or damp soil, eliminating breeding sites is critical. Swarming adults indicate nearby breeding areas, so controlling the larval stage is more effective than targeting adults alone. Rapid reproduction means populations can grow quickly during warm, wet conditions.