The influence of meteorological factors on the activity of adult taiga ticks (Ixodes persulcatus Sch., Ixodinae) in St. Petersburg and its environs

Resumo

The article deals with the influence of meteorological factors on the activity of the taiga tick Ixodes persulcatus Sch. in the city of St. Petersburg and its environs. The results of correlation analysis of meteorological data (21 parameters) and tick collection data for 1980-2012 demonstrated a linear dependence between 11 meteorological parameters and the mean abundance of ticks. Factor analysis reduced dimensionality down to 3 parameters: the accumulated temperatures higher than +5.0°C, the annual sum of daily precipitation amounts greater than 5 mm, and Selyaninov’s hydrothermal coefficient. It was shown that, while the mean abundance of active ticks in the studied territories tended to decrease, correlation between the abundance of ticks and meteorological parameters varied significantly in both intensity and direction depending on the microclimatic features of the collection sites. At low annual variation of the mean tick abundance, the methods of collection can significantly affect the results of statistical analysis. This fact should be taken into account when predicting both the timing and the intensity of the epidemiological season.