Abstract
The surveying method for quantitative determination of the population density of ticks was considered. 1. The Tullgren and the improved Tullgren apparatus were compared for the recovery percentage of Haemaphysalis longicornis larvae which were mixed into fresh grass and soil. The improved Tullgren apparatus was equipped with a holey plate which covered over samples and obstructed a radiant heat from the electric bulb. The recovery percentage of ticks by the Tullgren apparatus was about 25%. On the other hand, the recovery percentage by the improved Tullgren apparatus was about 90%, but it decreased with increasing sample volume. The collection time of ticks from soil was about two times as compared to that from grass. 2. The ticks in the pot cultured grass was separately collected from cutting plant and surface soil by the using of the improved Tullgren apparatus. The total recovery percentage was 76.4%. But the recovery percentage of ticks from surface soil was only 4.4%. 3. The improved Tullgren apparatus and the Flannel method, which was rubbing vegetation with a piece of flannel (1m×1m), were compared for the recovery percentage of ticks in artificially released plots in grassland. The improved Tullgren apparatus showed a higher recovery percentage, about 52%, than the Flannel method, about 23%, for the ticks in grassland. The mean recovery percentage by the improved Tullgren+Flannel method, which collected the ticks on plant by the improved Tullgren apparatus and the rest on the ground surface by the Flannel method, was about 57%. These results indicated that the method used both the improved Tullgren apparatus and the Flannel method in combination was the most suitable surveying method for determination of the quantitative population density of ticks, and the improved Tullgren apparatus was also suitable for collecting the wintering ticks.
