Christmas thoughts turn to Santa, Reindeer and insects. We all love the story of Santa’s visit to The Grouch. The Grouch barked at Santa, “Keep your reindeer out of the house! It’s full of fleas”. Santa turns to his reindeer ands says, “Please stay out of the house. It’s full of fleas.”
On a more serious note, insects (but not fleas) have a major effect on reindeer ecology. Reindeer herders have noted that during the summer months, insect harassment can cause reindeer to move constantly. Feeding may be interrupted and they may lose weight from too little feeding.
In arctic areas, insects will drive reindeer into large herds concentrated into small areas. Reindeer herders have traditionally used this insect-driven congregation to help manage herds. Herding behavior makes each individual less likely to be the one targeted by the a fly.
Human visitors to the northern latitudes are most impressed by the swarms of mosquitoes and black flies in Summer. While these pests do swarm around reindeer, they are not as harmful to reindeer as the warbles and nose bot flies (family Oestridae). Warble flies lay their eggs on the reindeer. Larvae hatch and burrow under the skin, feeding on the muscle. The nose bot fly tunnels into the soft tissue of the nose. This can cause difficultly breathing for the reindeer. Attacks by Oestrid flies can provoke violent escape reactions in individuals and herds.
Flies are a major impediment to reindeer husbandry. The insecticide, ivermectin, can control or kill the fly larvae, so there is some relief available. While reindeer cannot fly, perhaps the reindeer imagine that they can fly to escape parasitic flies in their dreams.
Warble Fly larva
Photo Credit: http://www.wildlife.alaska.gov/index.cfm?adfg=disease.skin5
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