Red pine sawfly (Neodiprion sertifer) on the Crimean pine

Abstract

Crimean pine Pinus nigra subsp. pallasiana has increasingly been introduced into crops in some regions of southern Russia, in particular in the Rostov region. There are no natural pine forests in the interfluve of the Don and Volga, but artificial plantings of this breed have been created here for more than 100 years. Here, often and on large areas, foci of mass reproduction of the red pine sawfly Neodiprion sertifer are formed. The first planting of Crimean pine showed that this pest did not damage it, preferring the Scotch pine Pinus sylvestris. This was the reason that the Crimean pine was increasingly planted on forest-cultural areas. To date, the share of Crimean pine plantings in the Sholokhov forestry has reached almost 30% of the total area of pine crops. The increase in the areas occupied by the Crimean pine led to the fact that soon the red pine sawyer began to damage it, and currently the foci of mass reproduction of the pest act both in the planting of ordinary pine and in the planting of Crimean pine. The conducted studies have shown that despite the development of a new forage breed for the sawyer in the region, he still continues to give preference to the common pine, initially settling it in mixed plantings. By the 13-year-old age of Crimean pine plantings, almost all trees are already inhabited by a pest, while the red pine sawyer masters the planting of ordinary pine almost completely, starting from the age of 5-6 years. The calculation of the number of eggs laid by females inside the needles on both types of pines was carried out. Statistically significant differences were not revealed, but at the same time, the number of eggs laid on one pine is slightly higher on the Crimean pine than on the needles of the common pine. It is suggested that the predominance of Crimean pine will lead in the coming years to the fact that the pest will damage this pine as much as it previously damaged Scotch pine.