Parasitic Deer Fly Population Spreads Across United States

A species of deer parasites known as deer keds, or Lipoptena cervi, is more widely distributed across the United States than previously thought, according to Pennsylvania State University entomologists, who noted the parasites' potential to transmit disease-causing bacteria.

According to study results published in the Journal of Medical Entomology, investigators collated records of the 4 North American deer ked species and produced a detailed locality map.

The records were collected through citizen science, in which the public gathered data on deer ked records from Canada and the United States. In addition to searching museum databases and community websites, the team distributed deer ked collection kits to hunters as part of the Pennsylvania Parasite Hunters community project and collected flies directly from carcasses at Pennsylvania deer butcheries.

Although the deer ked is known to exist throughout the Northeast, the report indicates that this species can now be found in Virginia and in 26 new Pennsylvania counties. Investigators found new records of the neotropical deer ked, Lipoptena mazame, in Missouri, North Carolina, and Tennessee, increasing its range farther north and east than previously reported.

Deer ked are usually found on deer, elk, and moose, but they occasionally bite humans and domestic mammals. Although several tickborne pathogens, such as bacteria that cause anaplasmosis, catscratch fever, and Lyme disease, have been detected in deer keds, investigators are unsure whether they can be transmitted through bites.

The investigators plan to screen hundreds of deer keds for pathogens and will dissect some insects to screen the guts and salivary glands separately. This method will indicate whether deer keds can transmit pathogens through bites or whether the bacteria are merely passed through the gut after a blood meal, according to the investigators.

Reference

Jones A. New records show spread of parasitic deer flies across the US. Penn State News website. news.psu.edu/story/576201/2019/05/30/research/new-records-show-spread-parasitic-deer-flies-across-us. Published May 30, 2019. Accessed June 14, 2019.