Timeline (or timeframe) of development of pine stem pests in the Left-bank Ukraine
The study consisted of classification of data on the dates of swarming and tree colonization by the most common stem pests of Scots pine (Pinus sylvestris L.) in the stands of Forest zone, Left-bank Forest Steppe and Steppe of the Left-bank Ukraine in the period of 2005-2014. Proximity of the date of the beginning of swarming in Tomicus piniperda to the date of stable transition of air temperature over 5 ºC, and in Tomicus minor, Acanthocinus aedilis, and the first generation of Ips sexdentatus and Ips acuminatus to the date of stable transition of air temperature over 10 ºC was statistically proved. The latest dates of timber removal after winter felling were determined as March 12 for Steppe zone, March 15 for Left-bank Forest Steppe and March 22 for Forest zone. The earliest dates of felling in autumn without risk of colonization by stem pests were determined as September 29 for Steppe zone, September 26 for Left-bank Forest Steppe and September 16 for Forest zone.