Gasterophilus haemorrhoidalis

Gasterophilus haemorrhoidalis (also called nose bot) is a species of the genus Gasterophilus.

This species of fly lays eggs in the fall on the face and around the lips and noses of horses, caribou, donkeys, and similar animals, usually equines. When the eggs hatch, the larvae proceed to the stomach of the host animal. The larvae grow in the stomach during winter. At the end of winter, the larvae are passed in the feces of the host, and they burrow into the soil to mature. Adult flies emerge several weeks later.

In the Northwest Territories of Canada, according to the Northwest Territories Environment and Natural Resources Wildlife Division, it lays eggs on and in the nose of caribou, and similar animals. The larvae grow in the sinuses and throat of the host animal, and are sneezed out in the spring.

External Links

• NWT Wildlife & Fisheries 'Nose Bot' page