Midges are small, flying insects, often mistaken for mosquitoes. They encompass various species, some of which bite and others do not. This article explains when these insects typically emerge and are most active throughout the year and day.
Key Periods of Activity
Midge activity patterns vary seasonally, becoming active from late spring through early autumn in temperate climates. Their numbers typically peak during the warmer summer months, often in July and August. In regions with consistently warm temperatures and high humidity, such as parts of Florida, midges can remain active year-round. The Scottish midge season, for instance, spans from late May to early September, with peak occurrences in July and August.
Within a single day, midges are most active during periods of low light, specifically around dawn and dusk. This crepuscular behavior allows them to avoid harsher midday conditions. Some species can remain active throughout the day, particularly if there is significant cloud cover.
Environmental Factors Influencing Emergence
Temperature plays a significant role in midge emergence and activity. Midges thrive in warm conditions, with activity often beginning when temperatures reach around 13 degrees Celsius. Peak activity for some species occurs between 16 and 18 degrees Celsius. Warm temperatures also accelerate their development, leading to quicker life cycles.
Humidity and moisture are important for midge populations. High humidity encourages midge activity, and they prefer damp, moist environments for breeding and survival. Larvae require aquatic or highly moist habitats, such as stagnant water, bogs, marshes, or wet soil, for their development. Adult midges also need access to free water to prevent dehydration.
Wind conditions significantly impact midge flight. These small insects prefer still air and are inactive in windy conditions. Midges struggle to fly in wind speeds exceeding 6 to 7 miles per hour, often seeking shelter in vegetation. Bright sunlight also suppresses their activity.
Midge Lifecycle and Presence Duration
Midges undergo complete metamorphosis: egg, larva, pupa, and adult. Female midges lay eggs in aquatic habitats or moist soil. Eggs typically hatch within a few days to a month, depending on the species and environmental conditions.
The aquatic larval stage involves four developmental phases. Larvae feed on organic matter in water or damp soil, remaining in this stage from two weeks to several years. Many midge larvae overwinter, continuing their development when warmer conditions return.
After the larval stage, midges enter a pupal phase, lasting from a few hours to about two weeks. The adult midge emerges from the pupa, typically near its water source. Adult midges have a short lifespan, usually ranging from a few days to a few weeks, though some species may live up to 20 to 30 days.
Adult midges primarily reproduce. Biting female midges require a blood meal for egg maturation, while others may feed on nectar. Many midge species can produce multiple generations within a single season, with some having one to two generations per year and others up to four. This multi-generational pattern allows for their sustained presence throughout the warmer months.