Biological Peculiarities of Archips rosana, the Insect Pest of the Sievers Apple Tree (Malus sieversii) in the Trans-Ili Alatau Ridge (the North Tien Shan)

The article provides new information on the phenology of a serious insect pest, the species of Archips rosana (Linnaeus, 1758) (Lepidoptera: Tortricidae), rendering fundamental harm to the Sievers apple trees, native to the Trans-Ili Alatau region (the North Tian Shan), which was not previously covered by studies. Material for research was obtained by the authors during two field seasons 2018-2019 by catching with an entomological net and making observations in nature at monitoring sites, as well as by growing all stages of development of the leafrollers in laboratory conditions of the Institute Zoology of Republic of Kazakhstan. The main objectives of the paper were set as follows: To establish the environmental factors behind the development stages of the A. rosana pest, to determine its phenological features and to identify the most vulnerable stage in its development in the given area. The paper describes in detail the study method and its outcome, workable in dealings against propagation of the pest and saving the indigenous Sievers apple tree. As a result, the most vulnerable stage convenient for combating the pest is the stage of the 1st - 3rd instar larvae which appear in the Trans-Ili Alatau during the period from the second decade of April to the second decade of May.