Study On Biological Control Of Red Turpentine Beetle Dendroctonus Valens (Coleoptera: Scolytidae) In China

The Red turpentine beetle (RTB), Dendroctonus valens LeConte (Coleoptera: Scolytidae), a common boring pest of conifers in North America, which was introduced to China by accident in 1990's from New World and spread rapidly to Shanxi, Henan , Hebei and Shaanxi Provinces in recent years. In 1999, the pest infested over 0.5 million hectares of forests of Pinus tabulaeformis Carr. and other species of pines and killed more than six million trees. It was found in Beijing in 2005. The invasive bark beetle has become a serious threat to Chinese forests.The State Forestry Administration of China and the local governments have carried out a series of control measures against the pests after its outbreakes, including to suppress the population of the pest using insecticides, to trap RTB adults with kairmone lures and to manage it in many other means. The efforts had contributed some effects to suppress its spread and the damage. However, because it has large population, hidden living and attack host trees under bark and over 80% individuals going under ground to feed on roots, the practices could not get ideal control results. The natural enemies are important factors to suppress pests under control in general. According to the classical theory of biological control, introducing the natural enemies of the exotic pest to the new invaded areas is a basical measure. However, no very effective natural enemies of D. valens was found in its native distribution area, i.e., in North America till now. But in Belgium, France, Britain and Georgia S.S.R, the biological control program won a considerable success by applying a predator, Rhizophagus grandis (Coleoptera:...