worm
December 12, 2009
A friend was cleaning a recently harvested florida whitetail deer and inside the jaws of the deer they found some kind of worms that were about the size of the first 2 joints of a females pinky finger. They were white and had pincher like things on what I’m assuming is the head end of the worm.
Susy
Central Florida

Nasal Bot Fly Maggots in a Deer

Hi Susy,
We are quite excited to get your image of Nasal Bot Fly Maggots in a Deer’s head.  According to the Missouri Department of Conservation Website:  “Nasal bot flies (Cephenemyia spp.) are common parasites that infest the nasal passages of deer. They most often are found by taxidermists while preparing heads for mounting, although hunters occasionally notice them.  Adult female flies deposit small larvae in the nostrils of the deer. The larvae enter the nasal passages and pass through several stages of development and growth. They are liberated when the deer sneezes. They then form a pupa and emerge as an adult fly.  Although quite large (up to 1 1/2 inches) and unpleasant looking in the final stages of development, nasal bots cause little harm to the deer and do not infect humans. They also do not affect meat quality.“  According to BugGuide:  “Eggs hatch inside the female fly and the newly emerged larvae are deposited in the nostrils of a suitable host. These larvae quickly migrate through the nasal passages into the nasopharyngeal (throat) region, preferably in the throat (retropharyngeal) pouches (causing nasopharyngeal myiasis in the host), where they settle and develop. After development is complete, the mature larvae are expelled from the host and pupate in the soil. Adults emerge after 2-3 weeks; since they do not feed, their life span is short and mating quickly ensues to complete the life cycle. 2 generations have been reported from the north, with the duration of each life cycle varying with the season. The winter life cycle can take up to 6 months, while the summer life cycle, half of that time.  Remarks  Usually the larvae do not cause considerable harm to the host other than mild irritation. However in the case of heavy infestations, results can be fatal for the host (death by suffocation), and consequently for the larvae (which, since are true parasites, cannot survive without a living host). Some members of the genus (e.g. C. trompe) are pests in reindeer farms in Europe, causing significant mortality and economic loss.”