Seasonal Fluctuations of Populations and Effects of Temperatures on Development and Growth in the Tick, Haemaphysalis flava

Abstract

As a part of ecological studies on Haemafihysalis flava, the seasonal fluctuations of tick populations in the vicinity of Fukuoka City were investigated, and the species and the number of ticks on hares were checked in winter. Moreover, the effects of temperatures on development and growth in H. flava were analysed. In the woodland, H.,L?ava was found on vegetation throughout the year, but in the grassland no ticks were found in summer. H. longicomis disappeared from vegetation during the November-February period of hibernation. H. flava was dominant on the hares captured in winter. In H.flava, oviposition, hatching and moulting did not occur at temperatures of 15% and below, and the developmental zero was 12.3"C. The critical low temperatures for moulting of larvae and nymphs were 14.5 and 17.O"C, respectively. High temperatures exerted a harmful influence upon oviposition and hatching. The temperature required for H. flava to be active was lower than that for H. longicornis, but the lowest temperature for development and growth in H. flava was higher than in H. longicomis, and the upper limiting temperature in the former tick was lower than in the latter : thus, it was revealed that H.,fIava develops and grows within a narrower range of temperatures than does H. longicornis.