The results of the treatments against the gypsy moth in the forestlands of the Omsk region, have shown that the new biopestucide “Defilignum” has a very high effectiveness. The treatments were carried out in May-June 2022 by order of the Omsk Forestry. Based on the pest control data obtained on the 15th day after the treatments, the effectiveness of the "Defilignum" is on average 82%. This indicator is significantly higher than the normally required threshold of effectiveness of pest elimination in the forestland (75%).