Lipoptena cervi

Lipoptena cervi, the deer ked or deer fly, is a species of biting fly in the family of louse flies, Hippoboscidae. These flies are commonly encountered in temperate areas of Europe, Siberia, and northern China. They have been introduced to North America. They are parasites of elk, deer, and other bovines, burrowing through the fur and sucking the blood of the host animals. L. cervi is relatively small, adults usually being 5–7 mm (0.20–0.28 in) in length and brownish in colour. Their bodies are flat and elastic, making their removal difficult. L. cervi is a poor flier and can only fly for short distances. Once the insect reaches its target, it sheds its wings and starts burrowing through the fur. L. cervi flies are not only a nuisance, but also represent a newly discovered vector for Anaplasma phagocytophilum, a Gram-negative, obligate intracellular bacterium that causes anaplasmosis, and also for Borrelia burgdorferi, the causative agent of Lyme disease. They will not reproduce on any other host than deer. They will, however, bite humans, and the bites are said to be painful and may cause an allergic skin reaction. Initially, the bite may be barely noticeable and leaves little or no trace. Within 3 days, the site develops into a hard, reddened welt. The accompanying itch is intense and typically lasts 14 to 20 days. Occasionally, an itch papule may persist for a year. The main annoyance in humans is the inconvenience and unpleasantness of removing keds from hair and clothes. Horses have been attacked, with severe symptoms of colic as a result. Dogs that are bitten may develop a moderate to severe dermatitis. German researchers have found that L. cervi can carry and spread Bartonella schoenbuchensis in deer. Remains of L. cervi have been found on Ötzi, the Stone Age mummy from the Schnalstal glacier in South Tyrol. Both males and females of L. cervi consume blood from their hosts. Feeding lasts 15 to 25 minutes. The female produces one larva at a time and retains the developing larva in her body until it is ready to pupate. The larva feeds on the secretions of a 'milk gland' in the uterus of its mother. The female gives birth to one fully mature white prepupa. She may produce larvae for as long as 10 months. A newborn prepupa immediately darkens, forms the puparium, and begins to pupate on the forest floor, or where the deer are bedded. After pupation, the winged adult emerges from the puparium and flies in search of a host. Upon finding a host, the adult fly breaks off its wings and it is permanently associated with its host. This species is found in most of Europe, including Great Britain (but absent from Ireland), Algeria, eastern Siberia, and northern China. It was introduced and is established in the Eastern United States (New Hampshire, Massachusetts, Pennsylvania, and New York). It has also spread to Finland from Russia in the early 1960s, where it primarily feeds on moose; though it is spreading to reindeer. Red deer, moose, roe deer, fallow deer, and Siberian musk deer are this fly's host. In the United States, it has acquired hosts such as elk, white-tailed deer, and reindeer. There are stray records of bites on humans, dogs and badger, and will occasionally commit to the wrong host.