Express method of accounting and forecasting brown-tail moth (Euproktis chrisorrhoea l.) in forest and garden plantations

Abstract

The biological peculiarities of brown-tail moth, a dangerous pest of many tree and garden plantings, were studiedin order to develop a rapid method for obtaining sufficientlyfast and reliable accounting and forecasting data. A comparative description of the existing methods of accounting ofbrown-tail moth in forest plantations and in garden ones hasbeen carried out. It has been established that the accounting methods adopted in production are devoid of statisticaljustification and data on the size and number of accountingunits. It is shown that the most informative indicator for obtaining data on the population of stands is the developmentof phytophage at the caterpillar phase in winter nests. Masscounts of winter nests with a simultaneous estimate of thenumber of caterpillars in them and the degree of nibblingof plantations made it possible to identify the relationshipbetween these values. Tables for quick determination of therequired sample size with three levels of accuracy are developed. A table establishing the number of pest larvae depending on the size of wintering nests has been developed. Amodel that allows predicting the degree of expected damageto plantings by a pest has been obtained.