Website Feedback Button
Fish and Game Home

Alaska Department of Fish and Game

Parasites and Diseases
Nose Bots

A Field Guide


caption follows
Caribou throat with two nose bots.

What causes nose bots?
  • This condition is caused by the larvae of the bot fly.
  • Lifecycle: The adult female bot fly deposits larvae in the nostrils of caribou. Nose bot larvae attach and grow in a cluster in the caribou’s throat near the base of the tongue. The larvae are sneezed out in the spring.

Where are nose bots found?
  • Nose bots can be found in caribou throughout their range in Alaska.

What are the signs of nose bots?
  • Caribou usually appear healthy.
  • When laying their eggs, bot flies harass caribou and interfere with feeding.
  • Nose bot larvae are found in the sinuses and airways at the back of the throat.
  • The worm-like larvae are white when they begin to develop but grow to ¾ to 1½ inches in length over the winter and become yellowish-brown.

How can I protect myself?
  • You cannot be infected by nose bot flies or their larvae.

Can I eat the meat?
  • Meat from affected animals is suitable for human consumption.

Samples to collect
  • Larvae of the bot fly
  • To report an occurrence or to submit a sample for identification/analysis, contact the DWC Wildlife Disease Surveillance reporting hotline 907-328-8354, send an email to or visit your local ADF&G office.
Please take a moment to help us improve your experience at the ADF&G website.
How did you arrive at our website?
Why did you visit our website today?
Did you find what you were looking for?
How easy or hard was it to find?
Very Easy Very Hard
Please provide any other comments or suggestions about your experience on the ADF&G website.

Having Trouble with this form?