The presence of tiny, biting insects is a well-known feature of the Scottish landscape during the warmer months. These small flies are collectively known as midges, with the Highland Midge (Culicoides impunctatus) being the species most responsible for human discomfort. They are a factor for anyone planning to spend time outdoors in Scotland.
Defining the Highland Midge
The Highland Midge is an exceptionally small insect, characterized by a dark body and a wingspan that measures only about 1.4 millimeters. Their small size allows them to pass easily through many standard insect screens. They can be distinguished from other flies by the presence of characteristic dark flecks on their wings.
Only the female midges require a blood meal to provide the protein needed for egg development. The female midge does not use a piercing proboscis like a mosquito; instead, she uses specialized, finely-toothed mandibles to cut a small wound in the skin. This action is often described as a sharp prick, and the insect then sucks up the resulting pool of blood.
The human body’s reaction to the midge’s saliva causes the familiar irritation. This often results in small, raised, itchy lumps that can persist for several hours or sometimes for days, depending on the individual’s immune response. Female midges often release a pheromone when feeding, which acts as an attractant, drawing dozens or even hundreds of other females to the same area for a mass attack.
Peak Season and Preferred Habitats
The period of highest midge activity in Scotland typically extends from late May or early June through September. Activity tends to peak in July and August, when warmer temperatures and consistent rainfall create favorable breeding conditions. Scotland’s climate provides an ideal environment for these insects, particularly the combination of high rainfall, boggy ground, and peaty soil.
Midges are most abundant in the Scottish Highlands and along the West Coast, where damp, marshy areas, woodlands, and the banks of lochs and rivers are common. These areas provide the wet, acidic ground necessary for the larvae to develop over the winter. Midges are primarily deterred by air movement, and their activity is significantly reduced by wind speeds exceeding 6 miles per hour (about 10 km/h).
Midges are crepuscular, meaning they are most active during the low-light hours of dawn and dusk. However, the insects will remain active throughout the day on still, overcast, or humid days that lack direct sunlight. Moving to higher altitudes (generally above 500 meters) or seeking out coastal areas with consistent breezes can often provide relief from their swarming behavior.
Practical Strategies for Midge Control
Outdoor enthusiasts can significantly reduce their exposure to midges by employing both chemical and behavioral defenses. Repellents containing specific active ingredients provide protection. Look for products that contain DEET, or the alternatives Picaridin (Saltidin) or Citriodiol (PMD), which are often formulated for Scottish conditions.
Covering exposed skin is a simple and effective physical barrier against the tiny insects. Wearing long sleeves, trousers, and a hat can prevent numerous bites, and midges are thought to be less attracted to light-colored clothing. For complete face and neck protection, a fine-mesh midge net worn over a hat is a highly effective, non-chemical solution.
Behavioral adjustments involve avoiding the conditions midges prefer, such as still, damp, and shaded locations, especially during their peak activity times. Staying in open, sunny, or breezy locations, and keeping a steady pace while walking, can prevent the formation of a biting swarm. Using a small fan can also be effective, as the slightest air movement is enough to ground the flies.