Experience of introducing the torymid wasp Torymus sinensis Kamijo as the specialized parasitoid against the invasive chestnut gall wasp in Russia

Abstract

The chestnut gall wasp (Dryocosmus kuriphilus Yasumatsu; Hymenoptera: Cynipidae) was first found in forests with the sweet chestnut (Castanea sativa Mill.; Fagaceае) in the area of Sochi, where it became the worst pest of chestnut. By now, the chestnut gall wasp has spread to all territories in which the sweet chestnut grows in the Krasnodar Krai. Besides, the condition of chestnut orchards and forests in this region for a long time cannot be considered satisfactory to chesnat due to the development of cryphonectric necrosis (Cryphonectria parasitica (Murrill) M. E. Barr) is causative agent of the disease). Control measures against the chestnut gall wasp have not been developed. A treat with pesticides are generally not effective because the chestnut gall wasp take cover inside the galls. And also pesticides can hurt honey bees and other beneficial insects. Moreover, pesticides use unacceptable in specially protected natural territories (SPNT), as well as near rivers, streams and settlements. The use of trunk injections is also impossible because the chemicals can make localize into the honey and nuts. To control the density of this phytophagous insect, the torymid wasp (Torymus sinensis Kamijo; Hymenoptera: Torymidae), which is its effective specialized parasitoid, was introduced. This entomophage is used as an agent of biological pest control against the gall wasp in countries where entered earlier. The introduction of the torymid wasp allowed to significantly reduce the pest’s population density, at the same time it did not harm natural ecosystems. This is the first case in the history of Russia of targeted introduction of a biological pest control agent into SPNT. The article describes the process of making an official decision, logistics and preliminary results of the introduction of a parasitoid in the territory of the Sochi National Park and the H. G. Shaposhnikov Caucasian State Natural Biosphere Reserve.

Keywords

• sweet chestnut
• torymus sinensis kamijo
• dryocosmus kuriphilus yasumatsu
• biological forest protection in specially protected natural territories
• sochi national park
• caucasian biosphere reserve
• krasnodar krai