The durability of forest ecosystems and sustainable development of forest management largely depends on forest resistance to various abiotic and biotic factors threatening their stability. Poland is on the verge between the Atlantic and the continental climate and therefore the species characteristic of both climates prevail in the pest insect fauna. Frequent insect outbreaks require application of protective treatments in forests. Today, the use of insecticides is most common. Modem forest protection responsible for the maintenance of forest sustainability should gradually depart from the use of insecticides and replace them with the more selective and environmentally friendly analogues of chemical compounds produced by insects or host plants. From the practical point of view, the use of pheromones and kairomones raise the greatest hopes of foresters. They belong to a group of semiochemicals i.e. the substances that are released by one organism and induce a response by another one. At present, semiochemicals are mainly used in forest protection for: 1) monitoring forest insects 2) determining the optimal time for applying salvage treatments, 3) reducing the population abundance of insect pests mainly bark beetles, through mass trapping or concentrations of males and females around wood logs to be then destroyed using mechanical means, 4) early detection of insects which are on a quarantine list. The mating disruption technique has the highest position among the most recent methods applying semiochemicals. This technique is widely used first of all in horticulture, particularly in reducing the abundance of codling moth (Cydia pomonella L.) and in the protection of vine plantations. In the last decade, this method has been also introduced in the US forestry to reduce population abundance and slow the rate of spread of gypsy moth (Lymantria dispar L.) into the uninfested areas of the country. In 2001, it was applied on an area of over 100,000 hectares, while sprays with the Bacillus thuringiensis formulation were carried out only on 32 hectares of forests. The idea of mating disruption is the release of pheromones into the air in a way that chemical information between males and females is disturbed, so males are no longer able to locate females. Thus, mating is interrupted. In Poland, the mating disruption technique against nun moth (Lymantria monacha L.) has been developed in the Forest Research Institutein cooperation with the CHEMIPAN R&D Laboratories, Institute of Physical Chemistry, Polish Academy of Sciences. The new formulation and the method of its application were patented. The attract and kill method is a recently developed novel approach successfully tested in horticulture. It relies on a spot use of a preparation containing a sex pheromone and an insecticide, which is distributed in the crop in the form of small droplets. Males are attracted by the pheromone and are killed by the insecticide. This technique allows abandoning of the large-scale sprays of the crop with insecticides. Preliminary trials using this technique have been made in Poland and the United States against European pine shoot moth (Rhyacionia buoliana Den. et Schiff) in forest plantations. The Forest Research Institute in cooperation with the CHEMIPAN R&D Laboratories have developed an original attracticide formulation Rhykil to be used in pest management of European pine shoot moth. The least recognised pest control method based on semiochemicals is the push and pull strategy. It depends on the use of repellents that causes a pest to make orientated movements away from its source (trees, stands and stacked wood) and attract it towards the source where it cannot cause damage, or is caught in a pheromone trap. So far, only a few trials with this method have been made against bark beetles of the genera Dendroctonus and lps.
