Lipoptena cervi, commonly known as the deer ked, is an ectoparasitic insect often mistaken for a tick. It is a type of fly that sheds its wings once it finds a suitable host, transitioning to a sedentary, parasitic lifestyle.
Understanding the Deer Ked
The adult deer ked measures between 4 to 7 millimeters in length, possessing a flattened body that aids its movement through dense fur. Its coloration ranges from dark brown to reddish-brown, providing camouflage within its host’s coat. These insects are classified as louse flies, belonging to the family Hippoboscidae.
Deer keds have strong legs equipped with claws, enabling them to cling firmly to fur and resist grooming attempts by their hosts. Both male and female keds feed on blood, using piercing mouthparts to access the host’s blood supply.
Geographic Range and Hosts
Lipoptena cervi is widely distributed across temperate regions, including most of Europe, Siberia, and northern China. It has also been introduced and established in parts of North America, particularly the Eastern United States, including states like New Hampshire, Massachusetts, Pennsylvania, Idaho, and New York.
The primary hosts for deer keds are various cervid species, such as white-tailed deer, red deer, elk (moose), roe deer, and fallow deer. These parasites spread through deer populations. While deer are their preferred hosts, keds can occasionally infest other mammals like horses, cattle, badgers, foxes, wild boars, and even humans.
Life Cycle and How They Behave
Unlike most insects that lay eggs, the female deer ked is viviparous, giving birth to fully developed larvae one at a time. These larvae immediately pupate upon being deposited, typically falling off the host onto the forest floor to complete their development.
The pupal stage can last several months, with adult keds emerging in late summer and autumn. Newly emerged adults are winged and actively fly in search of a host, often attracted by warmth. Once a suitable host is found, the ked quickly sheds its wings and burrows into the host’s fur, where it will live, feed, and reproduce.
Effects on Humans and Animals
Deer keds can cause irritation to their animal hosts. Heavy infestations can lead to scratching, rubbing, and discomfort in deer, potentially resulting in hair loss or secondary skin infections. For humans, deer ked bites are often initially unnoticed, leaving little or no trace. However, within about three days, the bite site can develop into a hard, reddened welt, accompanied by an itch that may last for two to three weeks, and occasionally for up to a year.
Deer keds are also considered potential vectors for certain pathogens. They have been found to carry bacteria such as Bartonella schoenbuchensis, which can cause inflammation around the bite site in horses and may be transmitted between ked generations. Anaplasma phagocytophilum, the bacterium responsible for anaplasmosis, and Borrelia burgdorferi, the agent of Lyme disease, have also been detected in L. cervi, though their role as vectors for these specific diseases in humans is not yet fully understood.
Preventing and Managing Deer Keds
Preventing deer ked bites involves minimizing exposure in affected areas, particularly during late summer and autumn when adults are actively seeking hosts. Wearing light-colored, long-sleeved clothing and a hat can make keds easier to spot and remove before they burrow into skin or hair. Some individuals also use fine-mesh netting over their heads or clothing for added protection.
If keds do attach, they can be difficult to remove due to their flattened, elastic bodies and strong claws. Prompt removal is recommended. Commercial insect repellents like DEET, IR3535, oil of lemon eucalyptus (OLE), and picaridin have not shown significant effectiveness in repelling deer keds. However, permethrin-treated clothing can cause keds to die more quickly upon exposure, offering some protection.