Our planet has a rich diversity of fauna ranging from unicellular microorganisms to gigantic animals. Insects constitute the largest group in the animal kingdom. Hence, although some of these insects such as mosquitoes and flies can be nuisance to us, their sustenance is critical for the ecological balance. Midges are type of flies that are profoundly found around estuaries, lagoons, swaps, tidal flats and mangroves. These are also termed as sand-flies in Australia. Midges are commonly referred to as "biting midges" as these insects have a tendency to go on biting frenzy. These insects have a unique ability to detect presence of carbon dioxide source from a distance of 200 meters and hence get attracted to animals and humans as they release CO2 during exhalation.
Midges are smallest two-winged blood sucking flies found world-wide. They so closely resemble mosquitoes that they are frequently mistaken for them. A midge is around 1 mm in length with small stout limbs and short mouthparts projected downwards. It bites both animals and humans inflicting excruciating pain. The female midges suck blood, whereas, both male and female feed on nectar and juices of vegetables. The female releases a chemical (pheromone) to intimate others about blood sources. These serious blood-sucking pests spread livestock diseases like Blue Tongue and African Horse Sickness.
The female midges lay eggs in saltwater, freshwater, fecal matter, mud, wet organic or vegetative matter, damp soil, decaying leaf litter, or under the bark of a tree. The larvae needs soft and moist platform to survive. The females feed on blood to lay healthy eggs. The eggs are laid in two batches. Each batch contains between 30-100 eggs. The first batch is larger in number and does not require the blood meal. The second batch is produced in late summer and autumn and requires blood meal to survive which leads to the biting frenzy. Small eel-shaped larvae hatch in a few days. The whole life cycle is completed within 3-10 weeks. It depends upon species and several environmental conditions such as temperature and moisture.
Bites inflicted by midges lead to extreme discomfort, local reactions and severe irritation. Severe reactions include blisters and serum oozing out from the site of the bite. Midges can also transmit infection causing pathogens in humans and other mammals. This situation is more common in Australia. Midges are known to cause a viral disease termed as Bluetongue. This disease mostly affects ruminant animals such as deer, cattle and sheep. This viral infection does not affect human beings.
Till date, there are no proven methods to control biting midges. However, one can reduce exposure to their bites. Try to avoid areas known for high midge population. Cover your exposed body-parts (hands, feet and neck) by wearing long sleeved tops and pants. Apply a repellent to exposed skin. Anti-pruritic medications like EURAX are prescribed for treating mild irritations. Antihistamines are recommended for severe bites.