К особенностям массового размножения древесницы въедливой (Zeuzera pyrina L.)

Abstract

In spite of big potential fertility of Zeuzera pyrina (more than 1000 eggs) the period of its mass reproduction is extended. The low fecundation of the laid eggs and death of the caterpillars during settling as a result of chemical treatment of the garden against Carpocapsa pomonella and others are the main reasons of comparatively slow reproduction of Z. pyrina. According to the approximate calculations the surviving generation of Z. pyrina amounts to 22% of instilled caterpillars or 0.2% of potential stock of eggs; the ratio of mother and daughter generations is 1 : 1.33. The calculation and formula are presented for computing the minimum technical efficiency of the measurements, providing the damping of Z. pyrina mass reproduction outbreak. So in old gardens of the Crimean steppe zone the measurement will be satisfactory, if, as a result of its effect, for the whole period of life not less than 70% of instilled caterpillars perish.