FACTORS AFFECTING THE ABUNDANCE OF THE TAIGA TICK IXODES PERSULCATUS SCH. IN NORTH-WESTERN PART OF ITS AREA

About authors:

N.M. Okulova, Institute for Problems of Ecology and Evolution RAS, Moscow, Russia
Е.А. Scadinya, Latvian Republican Sanitary and Epidemiological Station, Riga, Latvia
Т.К. Bobrovskikh,

Annotation:

The analysis of factors influencing the abun-dance dynamics of the taiga tick Ixodes persulcatus in the eastern province of Latvia during 11 years and in the southern part of Karelia during 9 years was carried out. The basic factors (x) significant for the tick abundance (8 for Latvia and 13 for Karelia) were revealed by means of the correlation analysis method. The equations of multiple regression were composed which are appropriate for forecasting the tick abundance (as a number of adult ticks per 1 km during the whole season). In the equation for Latvia three factors were used: xl — the sum of mean monthly temperature for August-September of the preceding year (determination coefficient R2=0.79), x4 — the same for December-January of preceding winter, R2 = 0.504; and x7 — the mean temperature in April (R = 0.151). In Karelia two factors were selected: x/ (R2 = 0.831) and (R, = 0.675). The observed and calculated data coincide in both cases with R2 = 1. The usage of these equations is limited by conditions presented in learning matrix.

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