The Research On Investigation Of Pest Occurrence And Control Of Wild Forsythia In Shaanxi

Forsythia can be thought as Chinese traditional medicine especially its fruit. This thesis describes the research of forsythia in Shaanxi province.The preliminary statistic investigation of the insect pests of forsythia included 4 main insect orders, which are Thysanoptera, Coleoptera, Lepidoptera and Hemiptera. Because the insect which belonged to Thysanoptera always broke out in the flora time of wild forsythia, the insect of Thysanoptera played main role of the insect pests of forsythia. This thesis describes the main research on investigating the pests, occurrences, dominance of insect population, the structure of insect community, the spatial insect distribution patterns and selecting the proper insecticide to the pest.The conclusion of this research shows that the main pests of forsythia include Haplothrips chinensis Priesner, herb-feeding ladybugs. Cnidocampa flavescens, Erthesina fullo Thunberg, Psylliodes punctifrons Baly harmed the forsythia less than others. H. chinensis severely harmed forsythia from March to May, especially in April, and its occurrences accorded with the flora time of forsythia, the ladybug fed on the leaves of forsythia and it occurred on one generation a year on average, the adult of overwintering generation harmed the leaves in May, and the larva started to harm the leaves severely when August come. C. flavescens harmed wild forsythia not seriously from June to October, lasting for almost 5 months. In addition, bugs and P. punctifrons occurred unseriously but have a even occurrence during each month.The predominance species of wild forsythia in Jinsuoguan of Tongchuan city can be H. chinensis Priesner and herb-feeding ladybugs. The predominance of other trial plot in the flora time of forsythia can be H. chinensis Priesner, but other pest transfer to harm forsythia not severely after the flora time. The pests community structure of wild forsythia have relatively simple, and the dominance of pest is conspicuous, but the diversity of pest community and the equality of distribution are relatively weak.Herb-feeding ladybugs and H. chinensis distribute as even pattern on forsythia, the ladybugs distribute the most in the top, then in the middle, the less in the based of the stem in vertical direction, but they have no sharp difference in each parts of the stem. Culture and chemical control can be used in controlling H. chinensis and ladybugs, what need to be concerned is that not only destroy the underground site of H. chinensis but also protect the environment and natural enemy, trying to use the biological control to prevent it. Chemical control should be implemented in the flora time of forsythia, the proper insecticide can be Beta-cypermethrin 5%. For ladybugs, it can be catch by hand and combined the chemical and biological control, the proper inseciticide can be Mirador 3.5% EC.