Mosquito or Midge?

It’s National Tartan Day and time to stop and pay attention to the scourge of the Scottish Highlands – the midge. Midges can be biting or non-biting but they all seem to arrive in an irritating cloud of winged masses. Wear your Tilley hat and bring bug spray.

Back in the States, non-biting midges are often mistaken for mosquitoes. It’s easy to understand why – they develop in standing water, swarm in large groups, and often show up on your porch in the spring. 

The most important difference between these two insects is that midges don’t have the proboscis to bite. This draws a crucial line between “nuisance pest” and “disease vector”. Mosquitoes use this mouthpart to suck blood from a human host, potentially spreading disease and often raising an itchy bite.

For one thing, midges often have short wings that don’t extend beyond their body, while a mosquito’s wings usually cover its body. Midges also don’t have scales and so you’ll notice that their wings are smooth – they don’t have the telltale fringe on their wing tips that a mosquito does. Finally, a midge tends to hold its front legs up in the air while resting, almost like it’s waving. Mosquitoes do the opposite; they often hold their back legs up in the air while resting. And if you notice a cloud of flying bugs this time of year, it’s probably midges. Mosquitoes don’t typically exhibit this swarming behavior.  

Both mosquitoes and midges are in the order Diptera, known as the “true flies” so it’s understandable to be confused. But if you use these tips, it should be easier to know exactly what insect is at your door if either one comes knocking.