杀虫剂对转Bt水稻靶标害虫二化螟和非靶标害虫稻飞虱种群数量的影响

为明确杀虫剂对转Bt水稻品种华恢1号(Huahui 1,HH1)靶标害虫二化螟Chilo suppressalis及其非靶标害虫白背飞虱Sogatella furcifera和褐飞虱Nilaparvata lugens种群数量的影响,于2014—2015年在江西省南昌市南昌县莲塘镇的广福试验基地进行田间试验,种植转Bt水稻和对照亲本水稻,分别对其进行施用杀虫剂和未施用杀虫剂处理,然后对经2种处理后转Bt水稻和对照亲本水稻田中靶标害虫二化螟幼虫数量及非靶标害虫白背飞虱、褐飞虱的若虫数量、成虫数量、总虫量(若虫数量和成虫数量之和)进行调查,并对这3种害虫田间种群数量的年份、水稻品种、杀虫剂影响因子进行方差分析。结果显示,转Bt水稻种植对二化螟幼虫数量影响显著,而施用杀虫剂处理未显著影响二化螟幼虫数量。转Bt水稻种植对白背飞虱和褐飞虱的若虫数量、成虫数量和总虫量无显著影响;而施用杀虫剂处理显著降低转Bt水稻及其对照亲本水稻稻田内白背飞虱和褐飞虱的若虫数量及总虫量,并显著降低白背飞虱成虫数量。2014年和2015年,施用杀虫剂和未施用杀虫剂转Bt水稻田内二化螟幼虫数量极低或未调查到;未施用杀虫剂转Bt水稻上二化螟幼虫数量仅在2014年显著低于未施用杀虫剂对照亲本水稻。2014年,未施用杀虫剂转Bt水稻和对照亲本水稻上白背飞虱总虫量最大值分别为1 037、1 376头/百丛,施用杀虫剂后分别降低至233、253头/百丛;未施用杀虫剂转Bt水稻上和对照亲本水稻上褐飞虱总虫量最大值分别为4 120、2 413头/百丛,施用杀虫剂后降低至367、410头/百丛;2015年白背飞虱和褐飞虱的发生规律与2014年相同。表明转Bt水稻可显著降低二化螟幼虫数量,但褐飞虱及白背飞虱数量没有降低,而施用杀虫剂可有效降低褐飞虱及白背飞虱数量。

Effects of insecticide application on the population quantity of target rice stem borer, Chilo suppressalis and nontarget planthoppers, Nilaparvata lugens and Sogatella furcifera of Bt rice

To evaluate the effect of insecticide application on the population quantity of the target stem borer Chilo suppressalis, non-target planthoppers Nilaparvata lugens and Sogatella furcifera in the field of transgenic Bt rice, the field experiments were carried out in the field of transgenic Bt rice Huahui 1 (HH1) and its parental line of non-Bt rice Minghui 63 (MH63) with and without application of insecticides in Guangfu test site in Liantang Town, Nanchang County, Nanchang City, Jiangxi Province from 2014 to 2015. Then the larvae population quantity of target C. suppressalis, and the nymph, adult and total population (sum of nymph and adult) of non-target S. furcifera and N. lugens on the Bt and non-Bt rice with and without application of insecticides were investigated. Variance analysis was conducted to analyze the three factors including sampling year, transgenic treatment and insecticide application which influence the field population quantity of the investigated insects. The results showed that transgenic treatment significantly affected the population quantity of C. suppressalis larvae, while application of insecticides did not significantly affected the population quantity of C. suppressalis larvae. Transgenic treatment did not significantly affected the nymph, adult and total population quantity of S. furcifera and of N. lugens, but application of insecticides extremely significantly affected the nymph, adult and total population quantity of S. furcifera and nymph and total population quantity of N. lugens. In 2014 and 2015, the C. suppressalis larval population quantity in the field of Bt rice with and without application of insecticides was extremely low or none. In the paddy field without application of insecticides, the population quantity of C. suppressalis larvae fed on Bt rice in contrast to non-Bt rice was just significantly reduced in 2014. In 2014, the peak population quantities of total individuals of S. furcifera in the Bt and non-Bt paddy field without application of insecticides were 1 037 and 1 376 head/100 plants, respectively, and reduced to 233 and 253 heads/100 plants after application of insecticides. In 2014, the peak population quantities of total individuals of N. lugens in the Bt and non-Bt paddy field without application of insecticides were 4 120 and 2 413 head/100 plants, and reduced to 367 and 410 heads/100 plants after application of insecticides. In 2015, the occurrence of S. furcifera and N. lugens was similar to that in 2014. Finally, it was concluded that the planting of transgenic Bt rice can effectively control the population quantity of target stemborer C. suppressalis, but couldn''t significantly decreased the population quantity of N. lugens and S. furcifera; the application of insecticide could effectively decrease the population quantity of N. lugens and S. furcifera.