Researches On The Characteristics Of Insect Pests COmmunity Structure And Control On Purple Osier (Salix Integra Thrnb) In Yimeng Mountainous Area

The insect community's composing, dominant population's occurrence law and control methods on purpul osier(salix Integra Thrub) in Yimeng Mountains Area were studied systematically from 1997 to 2002. The main contents and conclusions are as follows:1. Research ascertained the insect pests' component on purpul osier in Yimeng Mountains Area. The insect pests were belonging to 6 orders and 31 families both in Insecta and in Arachnida, and the 13 species, Phylloxerina capreae Borner, Plagiodera versicolora (Laicharting), Nycteola asiatica Krul, Saliciphaga archris (Butler), Lepyrus japonicus Roelofs, Salebria semirubella (Scpoli), Teia immaculata Gaede, Earias pudicana pupillana Staudinger, Helicoverpa armigera (Hiibner), Spodoptera exigua HUbner, Zeuzera coffeae Neitner, Rhabdophaga sp., Altica weisei Jacobson, were dominate population.2. Through systematic observation the dominant species' morphological characteristic, life history and biological habits had been described.3. The characteristics of the insect pest community structures on purpul osier were studied, and the conventional chemical control measures affected the structures. Studied showed that community richness were smaller in young gardens and were bigger in adult gardens. The diversity, richness and evenness were higher in natural gardens than in gardens with chemical control measures and in chemical control gardens the dominant species of pests were more obvious.4. Using cluster analysis the insect pests' community structure was researched in nature area. The 12 month in a year were classified into three groups: the first group included five months (Jan, Feb, Mar., Nov, Dec), in this period the number of pests was least. The dominant species in this period were the pest eating growth point. In this stage the community structure characteristic were: the number of species was less, species richness and diversity was lower, but evenness was highest. The second groups consisted of three months (Apr, May, and Oct), in this period the number of pests was increasing, the dominant species were the pest eating tender leaves orbristletail. The community structure characteristics were: the number of species was more, species richness and diversity was lower, but evenness was higher. The third group covered four months (Jun, Jul, Aug, Sep), in this period the number of pests was at most, and the community was prosperous. The dominant species in this stage were the pest eating leaves or piercing and sucking the sap of the trees. In this stage the community structure characteristic were: the number of species was at most. Species richness was highest. Diversity and evenness was lower. According to such analysis the strategy of the pests' management were put forward.5. According to a primary survey, there were more than 86 natural enemy species in the purple osier fields. They were belonging to Hemiptera, Coleoptera, Hymenoptera, Diptera, Neuroptera snd Arachnoidea.6. Some methods were tested to control several pests. With chbrbenzuron against Plagiodera vericolora and some selective insecticides, such as Mimic, Atabron and Hexaflumuron against Spodoptera exigua, good effectiveness were abtainde. Some systemic insecticides,carbofuram, phorate and aldicarb were applied in the soil to control some important pests, good efficacy was also got.