Investigation And Risk Analysis Of The Main Exotic Invasive Forestry Pests In Gansu Province

The forestry pests were investigated based on abundant field work and classification, integration, and collection with the former general investigation data in Gansu province. The risks of forestry pests spreading were analyzed, and the characteristics of forestry pests occurrence were summarized in Gansu Province. We explored the main reason why exotic invasive forestry pests happened at a large area in Gansu province in this study. The several suggestions provide for forestry pests control in the future.The results indicated that the mainly exotic invasive forestry pests total were 12 species in Gansu Province, including 8 insect pests (Adelges Laricis Vallot, Laspeyresia pomonella, Holcocerus hippophaecolus, Pristiphora erichsonii, Reticulitermes aculabialis, Cryhalus tabulaeformis chienzhuangensis, Phenacoccus fraxinus, Icerya purchasi Maskell),2 diseases (Botryosphaeria laricina, Gymnosporangium asiaticum Miyabae ex Miyabae), and 2 noxious plants(Solidago Canadensis, Melilotus albus). The host plant area of the insect pests and diseases was 56.6×104hm2, with heavily damaged area of 1.1×104hm2, moderately damaged area of 1.8×104hm2, and mildly damaged area of 3.0×104hm2. The damage rate was 10.31%.The occurrence characteristics of forest pests in Gansu province were as follows:(1) The kinds of local frequently forestry pests were rising, the pests occurrence area were larger and larger, which lead to the species of pests and diseases are keep increasing; (2) The invasive area of exotic forestry pests increased sharply; (3) The forestry quarantine pests and diseases spread quickly, causing a great threat to forest resources, environment, and natural landscape; the damage of accidental forestry pests was more significant; (4) The damage of rats (rabbits) was growing, and the area was 30.13% of the total damage areas; (5) The plant insect pests and diseases in economic forest were increasing year by year, including 68 insect pests and 29 plant diseases which damaging apple, pear, apricot, peach, and prickly ash trees; (6) The plants and trees were damaged seriously by the plant diseases and insect pests in the plantations.The investigation showed that the society had paid a little attention to the forestry pests control, the construction of forestry pests control system relatively lagged, the biotype in plantation was simple, and the invasive approaches of forestry pests were increased. All the above issues and the funding input problems are the reasons to the appearance of large occurrence area by exotic invasive forestry pests.