Combating Lyme Disease in Maryland

Mouse fitted with tracking collar

Image Credit: (c) Emmanuel Do Linh San

September 6, 2017 Kim Kaplan & Samantha Watters

College Park, Md - The College of Agriculture and Natural Resources is committed to improving human health and well-being locally, nationally, and internationally. With Lyme disease becoming an increasingly concerning problem around the state of Maryland, the Department of Environmental Science and Technology is moving into the next phase of a study launched by Dr. Jennifer Murrow in January of this year. White-footed mice in Howard County, Maryland are being collared as part of the study to improve control of the ticks that spread Lyme disease. This innovative mouse collaring research has never been implemented in Maryland before, and it represents a partnership between the Agricultural Research Service (ARS), Howard County Department of Recreation & Parks (HCRP), and the College.

Mouse tracking is part of a larger five-year ARS Tick Management Project evaluating the use of minimal pesticide or integrated pest management to reduce and control the black-legged tick population. Some of these ticks carry Lyme disease-causing bacteria and are around single-family yards and gardens adjacent to large Howard County parks.

While ticks that spread Lyme disease are commonly thought of in connection with deer, it is actually from infected white-footed mice that these black-legged tick usually acquire the bacteria responsible for the disease.

Starting now, an ARS and UMD team led by Murrow and graduate assistant Grace Hummell will live trap ten mice (five male and five female) at each of four sites using food and cotton as bait, which is attractive as nesting material. The four sites are near Cedar Lane Park, Middle Patuxent Environmental Area, Centennial Park, and Rockburn Park. 

Once a mouse is captured, the team will fit it with a tiny VHF radio collar to track its movements during periods of the next six weeks. Then, the team will recapture the mice and remove their collars. “Collars are the best option because it has been found that mice will chew out tags,” said Hummel. “Holohil makes their small mammal collars chew proof, so they are able to allow researchers a longer time frame to track the mice. 

Entomologist Andrew Li, with the ARS Invasive Insect Biocontrol & Behavior Laboratory in Beltsville, Maryland, coordinates the Tick Management Project and wants the data to better understand how white-footed mice respond to bait boxes that include tick treatments like topical insecticides.

“We need a scientific basis for where we put the bait boxes so we can have a sound expectation that mice will get enough acaricide to kill the ticks,” said Li. “Understanding the home range and activity pattern of mice will help improve host-targeted tick control.”

The next phase will come after the collaring season. "This will involve grid-trapping and releasing mice over multiple nights so changes in their location are tracked," said Murrow. This type of tracking has never been done in the state of Maryland before, and it will make it substantially easier to understand patterns and ultimately control the black-legged tick population and the spread of Lyme disease."