Biting flies are no laughing matter. Where are the biting flies in the winter? You might have noticed that those burning, stinging, bloody welt-inducing incidents have stopped. You might even breathe a big sigh of relief. So where do the biting flies go in winter? The simple answer is that they go to prepare for the next biting season. Let’s explore the lifecycle of these minuscule terrors.

The Many Forms of Insects
One key thing about insects is that they are not always in their adult form. Their life cycles are rather interesting in that they have evolved to deal with seasonal issues, such as cold winters, droughts, and even the scarcity of food.

The deer fly and horse fly are both dipterans — flies — and they have a complete lifecycle. They begin as an egg, hatch into larvae, form a pupa, and then emerge as an adult. The telling of where the biting flies go in winter is a story about their lifecycle.

Adult Deer Fly and Winter
The truth is that the adult deer fly species die when the weather turns cold. You might cheer at that thought or maybe raise your fist in triumph. However, by winter, the damage is already done. The female deer fly and horse fly both bite to ingest a blood meal. The entire purpose of that meal is to help them successfully produce eggs.

During their adult life, deer fly lay between 100-800 eggs. Every bite, every blood meal is a primer for another brood of eggs. Once the females have died off, their eggs are long hatched. The next population of deer fly secured. So as we raise our fist in triumph keep in mind it is the deer fly who has the last laugh.

Deer Flies and Overwintering
During the cold, winter months, the deer fly larvae are snugly enjoying a subterranean habitat. Once the eggs hatch, the larvae fall to the ground and burrow down into the soft, moist soil found around the margins of swamps, ponds, lakes, and wetlands. Here, they will burrow through the mud eating other insects, worms, and even each other. The earth is warm and the maggots enjoy an easy winter. Come the late spring, a portion of that population pupates and then emerges as adults. The laughter of man over the demise of last season’s adult deer flies becomes muddled curses emphasized by the slapping sound of a quick hand missing a clever predator.

You may feel that bit of laughter slide off your face as you read this but take heart. The key to eradicating deer flies and horse fly is to remove the adult females before they breed, bite, and lay that mass of eggs. The trick has a name — the Fly Cage. It is an effect means of attracting adult female deer flies and ending their reign of terror. The Fly Cage is effective against:

Horse Flies
Deer Flies
Green Heads
Yellow Flies
For every adult female biting fly the Fly Cage takes down, the next year’s population of predatory flies drops by 100-800. Now that is something over which you can rejoice.