Investigator:

Matthew Phelps

Advisor: Maria Diuk-Wasser

Description:

From May to August 2013, a team comprised of one postdoctoral fellow, a PhD student, three undergraduate students and myself, will collect host-seeking nymphal tick samples from 80 - 100 sites throughout the distribution of Ixodes scapularis ticks in New England states; the distribution of Bm infection is expected to represent a subset of that area. Sample sites will be selected using a stratified random design by overlaying a hexagonal grid over the study region using ArcGIS, and selecting random sites from all available state parks or other natural wildlife areas in each grid cell. Each site will be sampled twice over the summer using a standard tick-dragging technique - we will drag five 200 meter transects and use this to estimate infected and non-infected nymphal tick density.

Along with tick infection data, I will collect data on local environmental factors such as temperature, humidity and leaf litter composition along the transects where ticks are collected. Further environmental data, including climate data, topographic, land use and landscape fragmentation metrics will be downloaded from existing datasets. The tick collecting will be done over weekly trips to different parts of the study area and involve camping at state parks to minimize costs. Data from the collection trips will be geo-referenced using handheld GPS units. The data analysis will involve developing a Bm infection risk map by developing a spatially explicit model of the density of infected nymphs based on the local value of the covariates collected in the field or from existing datasets.  The predictive model will then be run for all pixels in the study area to generate a continuous risk surface.