A COMPARISON OF METHODS FOR SAMPLING THE DEER TICK, IXODES-DAMMINI, IN A LYME-DISEASE ENDEMIC AREA

The purpose of this study was to compare the trapping and examining of mice, drag sampling, and CO2-baited traps for their ability to detect the presence and abundance of immature deer ticks, Ixodes dammini, in a Lyme disease endemic area in southern New York State. Eight study sites were sampled 14 times between 28 May and 31 August by setting 49 live-traps, four CO2-baited traps, and drag sampling 500 m2. A total of 1540 nymphs and 3079 larvae was collected during the study. Drag sampling collected the most nymphs (705), while more larvae were recovered from CO2-baited traps (1105). Comparisons among the methods showed a significant difference in the numbers of both larval and nymphal ticks collected (P<0.01). There was a positive correlation between the numbers of nymphs collected by drag sampling and CO2-baited tick traps (r(s)=0.83, P<0.05), and between the numbers of larvae collected by drag sampling and mouse trapping (r(s)=0.75, P<0.05). These results suggest that drag sampling would be the single most reliable method for quantitatively sampling immature I. dammini populations in a Lyme disease endemic area.