Effects Of Transgenic Bt Cotton On The Insect Community Biodiversity In Dezhou

In recent years, the technology of transgenic Bt cotton has matured increasingly, and the technology has been commercially and practically used. In our country, the research on transgenic gene anti-pest cotton has greatly succeeded. More than 20 kinds of transgenic cotton strain with the character of high anti-pest, fertility, high quality, had been gained. Among them some varieties had passed the variety examination and approval (Huguoxiang, 2002). Through wide popularizing and application in cotton area in our country, social and economic benefit has been well obtained.Through comparison between transgenic anti-pest cotton and the non-anti-pest cotton field, the effect to the pest and natural enemy with sucking mouthparts, and community structure by transgenic cotton was studied in this article. And the stratigy about prevention and cure was discussed at one time. The study was divided into three parts.1. The occurrence and fluctuation of the primary pest populations in anti-insect cotton and non-anti-insect cotton was studied. The experiment show that the anti-pest cotton has evident fastness than the larva that with cotton bollworm as representation. The amount of above pest in non-anti-pest cotton field was greatly more than that in anti-pest cotton field. But compare with the non-anti-pest cotton field, the occur and ebb and flow of egg of cotton bollworm and other non-drone pest such as cotton aphis, cotton spidermite, cotton stinkbug, cotton weevil and other population, no distinct diversity was found.2. The occurrence and fluctuation of of the natural enemy populations in anti-insect cotton and non-anti-insect cotton field was studied. The result showed that the natural enemy with sucking mouthparts had same trend in anti-pest cotton field and in non-anti-pest cotton field. Although the amount of natural enemy in anti-pest cotton was more than that in non-anti-pest cotton field, their diversity wasn't distinct.3. The species component of insect community, the characteristics of insect community and dominance index of pest and natural enemy between anti-pest cotton field and non-anti-pest cotton field was studied. And the problems to which should be paid attention in cotton pest control was discussed. The study showed that with the decrease of using of pesticide, it was in favor of the survival and multiplying for diversified natural enemy, and it could promote ecological balance, advance the ability of controlling of the nature. The richness of insect community in transgenic Bt gene anti-pest cotton field was obviously high than that in non-anti-pest cotton field. The occurence of cotton aphis and cotton spidermite was more serious in transgenic cotton field. The diversity index of the pest and natural enemy was greatly affected by environmental condition in temporal sequence. The insect community in transgenic cotton varied rhythmically and the diversity index was partial high.