New records of parasitic deer flies (family Hippoboscidae) associated with white-tailed deer and moose have been reported in 14 U.S. states. These flies can cause significant blood loss and stress in their hosts, and may transmit diseases. The spread of these flies is likely due to a combination of factors, including deer migration, habitat changes, and climate change.
Background
Parasitic deer flies are obligate blood feeders that primarily feed on deer, moose, and other large mammals. These flies are typically 3-6 mm long, and have a dark body with wings that are clear or have a dark pattern. Deer flies can cause significant blood loss in their hosts, which can lead to anemia, weakness, and stress. In some cases, deer flies may also transmit diseases, including epizootic hemorrhagic disease (EHD) and tularemia.
New Records
New records of parasitic deer flies have been reported in the following U.S. states:
- Alabama
-Arkansas
-Connecticut
-Georgia
-Illinois
-Indiana
-Iowa
-Kansas
-Kentucky
-Louisiana
-Maryland
-Minnesota
-Missouri
-New Jersey
-New York
-North Carolina
-Ohio
-Oklahoma
-Pennsylvania
-South Carolina
-Tennessee
-Texas
-Virginia
-West Virginia
-Wisconsin
These records represent a significant expansion of the known range of parasitic deer flies in the U.S. Prior to 2010, these flies were only known to occur in a few states in the Midwest and Northeast.
Factors Contributing to the Spread
The spread of parasitic deer flies is likely due to a combination of factors, including deer migration, habitat changes, and climate change.
Deer migration: White-tailed deer are known to migrate long distances, and this can help to spread parasitic deer flies to new areas. Deer may also carry deer flies on their bodies as they move from one area to another.
Habitat changes: The expansion of suburban and rural areas has led to an increase in the amount of edge habitat, which is preferred by deer flies. Deer flies also prefer warm, humid climates, and climate change is likely making more areas of the U.S. suitable for these flies.
Climate change: Climate change is also likely contributing to the spread of parasitic deer flies. Deer flies are more active in warmer weather, and climate change is leading to warmer temperatures in many parts of the U.S. This allows deer flies to survive and reproduce in new areas.
Impact on Deer
Parasitic deer flies can have a significant impact on deer populations. The blood loss caused by these flies can lead to anemia, weakness, and stress. In some cases, deer flies may also transmit diseases, which can further reduce deer populations.
Management
There are no known effective methods to control parasitic deer flies. However, reducing the amount of edge habitat and managing deer populations may help to reduce the impact of these flies on deer.
Public Health Concerns
Parasitic deer flies can also pose a public health risk. These flies can bite humans, and although they do not typically transmit diseases to humans, their bites can be painful and can cause allergic reactions.
Conclusion
The spread of parasitic deer flies across the U.S. is a serious concern for deer populations and public health. Further research is needed to understand the factors contributing to the spread of these flies and to develop management strategies to reduce their impact.
