Reindeer (themed) Bugs


With Christmas fast approaching, we’re dedicating this article to Santa’s faithful sleigh-pulling companions – Rangifer tarandus, the caribou, better known as reindeer! While “caribou” invokes the imagery of great herds of deer migrating over tundra, “reindeer” makes us think about cutesy deer with soft, rounded-off antlers. As with all deer, when antlers are in their growth phase, they are covered in a fine layer of velvet, and the ends are blunted as they are still growing. When the antlers are fully grown, the velvet sloughs off to leave behind the typical pointy-ended antlers that we associate with big game deer species.

Decorative wings
Picture-winged flies and flutter flies has striking black patterns on their transparent wings. The patterns may look like bands, spots, patches, stripes, or some combination of these designs. The males often hold their wings above their body to display the pattern in order to impress the ladies. One species of flutter fly, Toxonerva superba, has a pattern that resembles reindeer antlers in their velvet stage. The illusion is much more apparent when the wings are being held upright in courtship display.

A strange parasite of reindeer
If you’ve ever owned sheep, you may be aware of a little parasitic bug called a sheep ked. Reindeer have a similar blood-sucking parasite, the deer ked or deer fly. These flies don’t look like your average fly. They belong to a group called the louse flies, which is a pretty accurate description of how they look. They are yellowish-brown in color with a dorsally flattened body (like a pancake) and stocky legs.

These little flies have wings but are very poor fliers. They fly just far enough to find their reindeer host. Then, they shed their wings, becoming flightless for the rest of their life. The now-wingless fly takes on the life of a flea, burrowing into the reindeer’s fur, living on the reindeer’s body, and sucking the reindeer’s blood to nourish itself. They are difficult to shake or scratch off due to their compressed, flexible bodies.

Deer keds have an interesting life cycle. Unlike most flies which lay dozens of eggs at a time, keds only develop a single egg which is hatched and retained inside the body. The resulting maggot feeds internally on secretions of the mother’s “milk gland,” growing larger and larger until it is almost time to pupate into an adult fly. The mother gives birth to a fully-grown, pale, inactive maggot which immediately begins to darken and harden into a pupa. The pupa develops on the ground (not on the host), undergoing changes similar to how a cocoon transforms into a butterfly, except the result is not nearly as beautiful. Once fully developed, the fly emerges from the pupa and flies off in search of its reindeer host.

In other parts of the world, deer keds feed on many species of deer, moose, and other bovines. While they occasionally bite humans, dogs, and even badgers, these are not their natural hosts. Keds will sometimes shed their wings and commit to the wrong host, but they cannot develop and reproduce without a proper host.