Mass Reproduction Outbreaks of Phyllophagous Insects in Forests of the Northwest of European Russia

Abstract

Data on the species composition and dynamics of outbreaks of needle- and leaf-eating pests that pose a danger to forest stands in Arkhangelsk, Leningrad, and Murmansk oblasts, as well as in the republics of Karelia and Komi, have been summarized and analyzed. A significant decrease in the frequency of reproduction outbreaks of certain types of needle- and leaf-eating pests is shown, which corresponds to the trends for some other regions. For the pine looper (Bupalus piniaria (L.)), the pine beauty (Pannolis flammea), the buff-tip (Phalera bucephala (L.)), the rusty tussock moth (Orgyia antiqua (L.)), and the white satin moth (Leucoma salicis (L.)), which have had a few mass reproduction outbreaks in the aforementioned regions, no significant increase in population density has been observed for 25 years or more. An increase in outbreak activity and expansion of the damage area to the north is likely for the winter moth (Operophtera brumata (L.)) and the autumnal moth (Epirrita autumnata). The larch tortrix (Zeiraphera griseana) and the spruce sawfly (Gilpinia hercynia) are in the list of potential dangers as well. These species have had only one reproduction outbreak, but it was extremely extensive. The red pine sawfly (Neodiprion sertifer Geoffr.) and possibly the common pine sawfly (Diprion pini (L.)) will continue playing a significant role as pests of young stands. The dynamics of their outbreaks, apparently, is determined by climatic changes and, to no lesser extent, by the presence of large areas of conifer regeneration. An increase in the fluctuation amplitude of the population density of the pests in urban plantations is likely to occur, especially for miner moths (Phyllonorycter isskii, Ph. populifoliella and Ph. apparella), for which the current climate warming is a fundamentally important factor.