Diversities of arthropod community in transgenic Bt cotton and nontransgenic cotton agroecosystems

In the first, middle and late stage of cotton growth, diversities of arthropod community, pest sub-community and natural enemy sub-community in the transgenic Bt cotton (GK-12) and nontransgenic cotton (SI Cotton 3) agroecosystems were studied. The treatments included: (i) GK-12 with no insecticide treatment,(ii) GK-12 with insecticide treatments, (iii) SI cotton with no insecticide treatment and (iv) SI cotton with insecticide treatments. The results indicated that in the first stage and late stage of cotton growth, diversity indexes of arthropod community and pest sub-community in the GK-12 with out insecticide treatment were higher than those in the SI cotton with out insecticide treatment. In the late stage of cotton growth, diversity index of natural enemy sub-community in the GK-12 with out insecticide treatment were higher than those in the SI cotton with not insecticide treatment. The F-test indicated that varieties×insecticide-treatment was the main factor influencing the diversity of arthropod community and natural enemy sub-community in cotton agroecosystem.