Project Number: 8042-32000-008-30-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 1, 2018
End Date: Aug 31, 2019
(1) Generate baseline data on tick population density and pathogen infection status of the white-tailed mouse in tick habitats; (2) Laboratory evaluation of toxicity and repellency of test compounds to ticks; and (3) Conduct field trials to evaluate efficacy of medicated rodent bait formulations in reducing tick population density and pathogen infection rate in ticks and their rodent hosts in environment.
(1) Generate baseline data on tick population density and pathogen infection status of the white-tailed mouse in tick habitats. Six field sites will be selected in tick habitats for this study in Massachusetts. Immature (nymphs, larvae) and adult ticks will be sampled / collected, at their respective seasons, from those field locations using flagging / dragging technique. White-footed mice, the main hosts of immature stages of the blacklegged tick, will be trapped using Sherman traps. Ticks infesting mice will be collected from each animal. Mouse ear tissue and blood samples will also be collected and properly preserved for pathogen testing. Tick and mouse tissue/blood samples will be tested for tick-borne pathogens using established molecular assays at Cooperator’s laboratory. Ticks will be maintained in a laboratory incubator under proper temperature and humidity conditions prior to behavioral tests. A vertical filter paper repellency bioassay technique will be used to measure response of individual ticks to different concentrations of DEET. The minimum effective DEET concentration that repels each tick will be determined. Each tick will then be assigned with a unique ID # and preserved in 80% ethanol. (2) Laboratory evaluation of toxicity and repellency of test compounds to ticks. Systemic pesticide compounds will be dissolved in cattle blood or tick saline and fed to ticks through capillary feeding. Tick mortality will be assessed to establish dose/concentration-mortality relationship. Behavior assays will be conducted to test sub-lethal effects of test compounds on tick locomotion and responses to repellent or attractant compounds. (3) Implement field trials to evaluate efficacy of medicated rodent bait formulations. Two different medicated rodent bait formulations will be selected for field efficacy evaluation. Among the six field locations, two will be used as untreated control site, two will be used formulation 31, and two will be used for formulation #2. Medicated rodent baits will be deployed at proper time of the year to target nymphal (May – July) and larval (July – September) tick seasons. Rodent trapping and tick sampling will be carried out every two weeks throughout the immature season (May – September). Tick control efficacy will be determined by comparing tick density and pathogen infection status at treated sites and untreated sites.