Investigation On Biological Diversity Of Forest Pest And Natural Enemies In Liaocheng City Of Shandong Province

The forest land in Liaocheng City is mostly pure plantation.The structure of the stand is simple,the biodiversity is poor,the species and quantity of natural enemies are few.In addition,in recent years,due to high temperature and little rain,weak forest trees,high base of forest pests,the risk of forest pest disasters increases.In order to find out the species,distribution,harm,host plants and other aspects of the main forest pests,the method of artificial inspection was used to investigate the forest and nursery in Liaocheng city,and a complete list of pests and weeds was obtained.There are 290 species of Lepidoptera,Hemiptera,Coleoptera,Diptera,Orthoptera and Hymenoptera of 6 orders,73 families in the whole city.Natural enemies are Hymenoptera,Coleoptera,Neuroptera,Hemiptera,Mantodea,Odonata of 6 orders,9 families and 18 species.According to the position of pests,225 species of leaf eating pests,75 species of apical bud and shoot pests,74 species of stem boring pests,37 species of fruit and flower pests and 31 species of underground pests were classified.Leaf eaters and stem borers account for 68% of the total pest species.The ratio of pests to natural enemies is about 16:1.The biological community structure of harmful insects in forestry was analyzed.It was pointed out that the insect groups were the most abundant from July to September,which was also the peak period of active insect pests in Lepidoptera,Hemiptera and Coleoptera.There are 120 diseases investigated and identified in the city,including 101 diseases caused by fungi,10 diseases caused by bacteria,3 diseases caused by virus,4 diseases caused by Mycoplasma and 2 physiological diseases.According to the classification of the damaged parts,80 kinds of leaf diseases,48 kinds of branch diseases,5 kinds of root diseases and 19 kinds of seed diseases are classified,among which the most are leaf diseases and branch diseases,accounting for the most.85% of the total number of classes.There were 1 species of the class,5 species of spider mites,1 species of mollusks and 17 species of harmful plants.According to the survey,1 new record was found in the province.We also analyzed the occurrence of Hyphantria cunea and Corythucha ciliata.The results of the investigation laid a foundation for guiding the green prevention of forest pests in Liaocheng City.