Cotton Cotton Insect Community Structure And Population Dynamics Study

Since the 1980s,Cotton bollworms (Heliothis armigrea) have done harm to cotton more seriously and been a huge threat to the stable and sustainable development of cotton planting. Now many countries in the world have developed many trangenic boll-worm resistant cotton varieties. Since the 1990s china has also developed our own boll-worm resistant hybrid cotton varieties. But what is the influence of the varieties on the main other insects? What influence is given to cotton bollworm? So it is significant to make sure . The experiment is done to find out the influence to ensure the sustainable development of cotton planting and the comprehensive management of pest.The experiment is involed in three types of varieties: hybrid boll-worm resistant variety (HBR), conventional boll-worm resistant variety (CBR), conventional boll-worm non-resistant variety (CNR). From June the fifth to September the 30th, investigation is made every five days, from five sites on the diagonals of cotton field, to find out the index of dominance , index of evenness and index of diversity, to make the influence clear of HBR on the stability of insect community.The result shew: HBR functions higher-yielding better resistance to boll-worm, andsmaller pest population Three types have the same influence on natural enemies ofpests.Amony the main insects, cotton bollworm is not the dorminant species and do less harm to cotton. The insect community was more stable and did no harm to natural enemies and was enable to keep the benign circle of insect ecosystem in HBR field.