Fig. 4.
Mean numbers of A. americanum ticks repelled by pondberry crude extract, fractions (−20, −42, −61 and −200 °C) and acetone in vertical filter paper bioassay. Ticks that fell from the filter paper or were in the lower untreated portion of the paper at 15 min after initially clinging to the paper were considered repelled. Three groups of 10 ticks each were tested per extract, fraction and acetone control. Columns with the same number of asterisks do not differ significantly (P > 0.05) according to ANOVA.