Location: Invasive Insect Biocontrol & Behavior Laboratory
Project Number: 8042-10400-001-007-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 15, 2025
End Date: Sep 14, 2028
Objective:
The objectives of the proposed research are to (1) develop new mouse bait formulations containing various levels of selective active chemical compounds that can result in a range of serum concentrations in mice that are lethal to ticks and/or the pathogen (Borrelia burgdorferi); (2) conduct in vivo animal (white-footed mouse) trials to evaluate efficacy of mouse bait formulations with various levels of the active ingredient against the pathogen infecting mice and immature black-legged ticks that feed on mice; (3) determine the best mouse bait formulations containing an appropriate level of active ingredient that is effective against ticks and tick-borne pathogens infecting mice and is also safe to mice for field evaluation; and (3) conduct field trials to collect efficacy data for product registration with regulatory agencies.
Approach:
(1) Development of medicated mouse bait formulations
The new medicated mouse bait formulations will be made by (1) adding a certain concentration of the test compound/active ingredient to a standard mouse bait formulation, and/or (2) by producing new bait formulations using the natural product that contains the test compound. The new mouse bait formulations will be tested for acceptance and the daily intake by males and females of the white-footed mice and their effects to mouse behavior, weight gain, and health in general. The data will be compared to those obtained from using the regular mouse bait formulation without the test compound.
(2) Determination of pharmacokinetics of test compounds in mice.
White-footed mice will be purchased from a commercial source. Test animals will be assigned into four different treatment groups based on the content (%) of the test compound. Mice fed with regular mouse bait without the test compound will be used as the control group. Test animals in each test group will be fed with a test bait formulation for 3 weeks. Mouse blood samples will be taken from each mouse at 0, 1, 3, 5, 7, 14, 21, 28, 35 days to determine the serum concentration of the test compounds. Mouse blood samples will be analyzed using GC-MS to determine concentration of the test compounds in mouse serum.
(3) Evaluation of medicated mouse bait against Borrelia burgdorferi infection in mice and ticks feeding on mice
White-footed mice will be purchased from a commercial source and be artificially infected with the pathogen through injection of cultured pathogens (Borrelia burgdorferi. Test animals will be assigned into different treatment groups based on the content (%) of the test compound in the mouse bait formulation. Mice fed with regular mouse bait without the test compound will be used as the control group. Mice will be fed with medicated mouse baits daily for three weeks. Mouse ear tissue and blood samples will be taken from each mouse at -2, 0, 3, 7, 14, 21 days to determine mouse infection status. The Buorrelia-killing efficacy of mediated mouse bait formulations can then be determined. To determine the effect of the test compound in mouse blood on tick feeding and mortality, each mouse in all test groups with be infested with 20 nymphs of the blacklegged tick following the established protocol. Tick attachment and mortality will be monitored daily or every other day for 7 days. The effects of the test compound on tick attachment, blood feeding and mortality can be determined by comparing the treatment groups with the control group.
(4) Project Assessment, Data Analysis, and Report
ARS is responsible for project management. The experimental designs will be developed jointly. Project progress will be assessed on a regular basis to identify deficiencies and to solve any issues. This will be achieved through regular email and phone calls between the USDA scientist and the cooperator and site visits. Data will be reviewed/analyzed jointly, published jointly in journals, or used for joint patent application(s). Cooperator will submit quarterly progress reports to ARS and a final report at the end of the agreement period.