Effects Of Transgenic Hybrid Rice(ⅡUKF6) On Arthropod In Fields

Field investigations and laboratory experiments were carried out to test the effects of the transgenic hybrid rice (â…¡KF6) on the arthropod community in paddy fields with chemical control, population dynamics of the major insect pests in paddy fields without chemical control, and biological responses of the major target pest Cnaphalocrocis medinalis, non-target pest Nilaparvata lugens and predatory natural enemy Tetragnatha nitens to the transgenic hybrid rice directly and indirectly, with conventional hybrid riceâ…¡YM86 as the control. The results were as follows:1 Effects of transgenic hybrid rice on the Arthropod Community in paddy fieldsIn the control of pesticides, species richness, diversity indices, evenness and dominant concerntration index of the arthropod community, insect pest sub-community and spider sub-community in the transgenic rice field were consistent with those in the control field, while rare species of non-target insect pests such as Menidahistrio, Nephotettix bipunctatus, Empoascanara maculifron, Laodelphax striatellus became frequent species in the transgenic rice field, and C. medinalis as the dominant species in the control field was the rare species in the transgenic rice field.2 Effects of transgenic hybrid rice on the target pest C. medinalis.Transgenic hybrid rice had higher resistance to C. Medinalis. The population density of C. Medinalis and damage rate of plants or leaves in the transgenic rice field were all significantly lower than those in the control field. Biological test in lab showed that at different growing stage of rice,â…¡KF6 could significantly adversely affect the survival, development and pupation of C. Medinalis, while had no significant effects on the preference of feeding and oviposition. The activity of carboxlesterase (CarE) of C. Medinalis. was lower when feeding onî—…â…¡KF6 than that onâ…¡YM86, while no significant difference of acetylcholinesterase (AChE) was found.3 Effects of transgenic hybrid rice on the non-target pest N. lugens.Transgenic hybrid rice had no significant effect on parameters of N. lugens, such as population dynamics, body weight, sex ratio, feeding preference, oviposition choice and activity of CarE and AChE. 4 Effects of transgenic hybrid rice on the predatory natural enemy T. nitensEffects of transgenic hybrid rice on the bionomical characteristics of T. nitens through its preys C. medinalis were studied in the lab, with larvae of C. medinalis fed onâ…¡KF6 for a given time as preys. The results showed that there was no difference in the mortality and fecundity of T. nitens betweenâ…¡KF6 treatment and the control when they were continuously fed on leafrollers for 7 days, 14 days or 21 days, respectively. The growth rate in weight ofâ…¡KF6 treatment was significantly higher than that of the control in the first week, while in the second week the result was reversed, as for the third week the difference was not significant. Although both predatory functional responses of the spiders followed the Hollingâ…¡model, after 7 days the predatory capacity of spiders for leafrollers fed onâ…¡KF6 was significantly lower than that of the control. Both the activities of AChE and CarE in spiders were obviously enhanced underâ…¡KF6 treatment, except for AChE in the third week.