Study On Population Structure Of Insects And Control Technique Of Main Pests On Rehmannia Glutinosa

Rehmannia glutinosa Libosch is the scrophulariaceae plant, one of the commonly used Chinese native medicines. It can not only nourish yin but also help produce saliva. It can clear away heat, help cool blood, stops bleeding, benefits spirits and marrow. It is good for the cool blood body and shortage of body fluid. It is Chinese native medicine of much benefit and has much clinical practice. This research is mainly done on the population distribution and the community diversity of rehmanniae. The research is carried out on the pesticide without social effects of pollution. It has provided the theory basis for preventing and controlling rehmanniae and the standard production. The results are as follows:1. In Hanzhong area 73 kinds of the arthropod are found and investigated, which include 2 classes, 11 orders and 45 families, of which there are 48 kinds of phytophages, belonging to 29 families; 19 kinds of predators belonging to 10 families; 2 kinds of parasitorids belonging to 2 families; there are other 4 kinds belonging to 4 families. Among insects, the Lepidoptera are the most, and next is the Coleoptera.2. The index of richness and the dominance in field harmful insect is highest for the Lepidoptera. The index of diversity and uniformity is the highest among Homoptera. The natural enemy of the rehmanniae is the Hymenoptera which have higher diversity and riches, but the spider uniformity and dominance are highest. The dynamic time of insect community indicates that in August there are large quantities of insects, the richest species, the hightest diversities, the most individuals and the highest uniformity.3. The distribution pattern of rehmannia flea beetle and spider population in the field displays in the pattern of aggregation primarily. Results of rehmannia flea beetle population research indicate that the index of M*/M,C and CA display 8 aggregated patterns, 3 uniform distribution from 26th July to second November. And spider population has 10 aggregated patterns and 2 uniform distributions.4. Synthetic analysis of 40% Phoxim EC 1000x,1.8% Avermetins EC 5000x and10% Imidacloprid WC 5000x are good control effect for rehmanniae and slightly effect natural enemy, so they can act as the effective medicament to control rehmanniae. 5. Toxicity of five kinds of pesticides against the rehmannia flea beetle from high to low in turn are Deltamethrin > High-active Cypermethrin > Phoxim > Avermetins > Imidacloprid. This illustrates rehmannia flea beetle are most sensitive to Deltamethrin, High-active Cypermethrin and Phoxim, but they are less sensitive to the Imidacloprid.6. Determining residual dynamics of Avermectins on leaf and root from rehmanniae, residue is respectively 0.0134 mg?kg-1 and 0.0164 mg?kg-1 after 15 days treatment. The degeneration rate of Avermectins is 95.69% and 92.42% respectively, which accord with the national standards of the highest residue limits in food.