虫酰·辛硫磷20%乳油防治稻纵卷叶螟和稻飞虱初步试验

试验结果表明：在稻纵卷叶螟的卵孵始盛期和稻飞虱的若虫盛期,用虫酰·辛硫磷20%乳油100g/667m2,药后15d对稻纵卷叶螟与稻飞虱的防治效果均达到95%以上。对稻纵卷叶螟的防治效果显著优于稻丰散50%乳油120g/667m2,对稻飞虱的防治效果与吡蚜酮25%可湿性粉剂25g/667m2之间无显著差异。     

食诱剂监测稻纵卷叶螟种群动态初报

2020年7月-10月在我国南方3大稻区的6省(区)12个点开展了稻纵卷叶螟成虫种群动态的食诱监测试验,并与性诱、灯诱和田间赶蛾等传统监测技术进行了对比.结果表明,食诱监测可准确反映田间稻纵卷叶螟种群数量动态,其峰次、峰期与性诱、灯诱和田间赶蛾基本一致.4种监测方法在长江中下游单季晚稻区、单季中稻区和华南双季晚稻区同期...     

稻纵卷叶螟成虫日龄的判定指标

本研究旨在明确稻纵卷叶螟成虫生化和形态指标与其日龄之间的关系,为建立稻纵卷叶螟成虫日龄判定的数学模型和预测预报提供理论依据。通过提取稻纵卷叶螟成虫头部生化物质和解剖其生殖器官,研究了羽化后1～6日龄雌雄成虫头部褐脂质、蝶啶含量的变化以及雌蛾卵巢小管和雄蛾精巢的发育状况。研究表明:(1)不同日龄间雌、雄成虫头部褐脂质、蝶啶含量均无显著差异。(2)不同日龄间雌蛾卵巢小管长度、雄蛾精巢大小均具有显著差异(P0.05)。雌蛾1～3日龄、3～6日龄卵巢小管长度与日龄的线性相关系数(R~2)分别为0.615 2和0.128 4。雄蛾精巢长半轴、短半轴长度与日龄的线性相关系数(R~2)分别为0.578 4和0.579 6。(3)利用卵巢小管长度对低日龄雌蛾日龄的估计表明:1 d估计误差平均为±0.56 d,2 d估计误差平均为±0.47 d。利用精巢长半轴对雄蛾日龄的估计表明:1～6 d估计误差平均为±1.28 d、±1.48 d、±1.43 d、±1.32 d、±1.53 d和±1.29 d。利用精巢短半轴对雄蛾日龄的估计表明:1～6 d估计误差平均为±1.15 d、±1.04 d、±0.97 d、±1.12 d、±1.46 d和±1.21 d。综上,头部褐脂质和蝶啶不能准确反映稻纵卷叶螟成虫日龄的变化,不能作为其日龄判定的指标。而雌蛾卵巢小管和雄蛾精巢形态稳定,其大小变化与日龄具有一定的对应关系,卵巢小管和精巢在稻纵卷叶螟成虫日龄的判定中具有较大的应用潜力。     

甲胺磷对稻纵卷叶螟及其天敌的影响

实验室、田间试验表明 ,甲胺磷对稻纵卷叶螟及其寄生蜂、捕食性天敌等均有不同程度的杀伤作用。各代推迟喷药、放宽防治指标可提高纵卷叶螟幼虫被寄生率 ,对产量并无影响。结合前期施药对褐飞虱再增猖獗的促进作用 ,建议在水稻生长前期谨慎用药 ,尤其应限制甚至禁止在稻田使用甲胺磷。     

纵卷叶螟绒茧蜂对稻纵卷叶螟幼虫的功能反应

在室内测定了纵卷叶螟绒茧蜂Apanteles cypris对稻纵卷叶螟Cnaphalocrocis medinalis幼虫的功能反应和寻找效应。结果表明,纵卷叶螟绒茧蜂对稻纵卷叶螟幼虫的功能反应可用Michaelis-Menten-Ⅱ型功能反应模型Na=AN0/(F+N0)拟合,一头纵卷叶螟绒茧蜂雌蜂在24h内对稻纵卷叶螟幼虫的寄生潜能A为10.7528头,寄主半饱和密度F为14.3864头。纵卷叶螟绒茧蜂的寄生功能反应有较强的种内干扰作用,即随自身密度的增加,寄生数量逐渐减少。Hassell模型E=QP-m能较好地反映纵卷叶螟绒茧蜂的寻找效应与其自身密度的关系,拟合结果为:E=0.2956P-0.5890。     

转cry1Ab基因粳稻对稻纵卷叶螟成虫产卵行为的影响

为评价转cry1Ab基因粳稻(KMD1和KMD2)对稻纵卷叶螟Cnaphalocrocis medinalis(Guenée)成虫产卵行为的影响,采用"Y"型嗅觉仪和笼罩以及田间试验等方法对稻纵卷叶螟成虫对转基因水稻的趋性以及其产卵选择性进行了研究,并利用固相微萃取和GC-MS技术测定了这2种Bt水稻及其对照亲本秀水11挥发物的组成及其相对含量。结果表明,稻纵卷叶螟成虫在"Y"型嗅觉仪和小型笼罩内对Bt水稻和对照亲本的选择性差异不显著,而在大型笼罩和田间条件下均显著趋向于在非转基因水稻上产卵,其中大田中稻纵卷叶螟在KMD1、KMD2和对照中的百叶卵量分别为2.20±1.28、1.00±0.77和5.60±2.16粒。水稻挥发物的组成及其相对含量在Bt水稻及其对照亲本之间差异不显著。表明相对于Bt水稻,在田间条件下稻纵卷叶螟成虫趋向于在非转基因水稻产卵,而水稻挥发物可能不是引起这种行为趋性的直接原因。     

Effects of Melia azedarach on nutritional physiology and enzyme activities of the rice leaffolder Cnaphalocrocis medinalis (Guenée) (Lepidoptera: Pyralidae)

Laboratory assays were done to evaluate the effect of Melia azedarach L. (Rutales: Meliaceae) seed extract on nutritional indices and gut enzymes acid phosphatases, alkaline phosphatases, adenosinetriphosphatases, and lactate dehydrogenase of the rice leaffolder (RLF) Cnaphalocrocis medinalis (Guenée) (Lepidoptera: Pyralidae). Larvae were fed a treated rice-leaf diet containing the seed extract and their midgut was used for enzyme determination. Laboratory experiments showed that the seed extract suppressed the larval activity of C. medinalis even at a low dose. Gross dietary utilization (efficiency of conversion of ingested and digested food) of RLF decreased after ingesting the treated rice-leaf diet. Food consumption, digestion, relative consumption rate, efficiency of conversion of ingested food, efficiency of conversion of digested food, and relative growth rate values declined significantly. As compared to the control, consumption of the extract containing rice-leaf diet resulted in a 69% reduction of the acid phosphatases activity, a 71% reduction of the alkaline phosphatases activity, a 46% reduction of the adenosine triphosphatases activity, and a 52% inhibition of the lactate dehydrogenase activity.     

不同类型杀虫剂对水稻二化螟及稻纵卷叶螟的田间防治效果评价

基于同时防治水稻二化螟及稻纵卷叶螟的杀虫药剂较少的现状,2014年采用田间小区试验探索了有机磷类、沙蚕毒素类、酰肼类、多杀菌素类、取代苯基吡唑类、缩氨基脲类、噁二嗪类、大环内酯抗生素类及双酰胺类等9类16种杀虫剂对二化螟和稻纵卷叶螟的防治效果。结果表明,200g/L氯虫苯甲酰胺SC和10%阿维·氟酰胺SC能有效控制二化螟和稻纵卷叶螟危害,且速效作用好、持效期长达28d,药后7~28d对二化螟和稻纵卷叶螟的防治效果分别为84.85%~93.37%和80.40%~86.16%。60g/L乙基多杀菌素SC、1.8%阿维菌素EC、20%氟苯虫酰胺WG、40%氯虫·噻虫嗪WG、6%阿维·氯苯酰SC和10%四氯虫酰胺SC对二化螟的防治效果好而对稻纵卷叶螟有一定的兼治作用,药后7~28d防治效果分别为81.13%~97.17%和62.17%~85.26%。240g/L氰氟虫腙SC对稻纵卷叶螟的防治效果好而对二化螟有较好的兼治效果,药后7~28d防治效果分别为76.98%~92.16%和76.37%~80.98%。1%甲氨基阿维菌素苯甲酸盐ME对二化螟及稻纵卷叶螟的防治效果较好,速效性好且持效期较长,药后7~28d防治效果分别为69.29%~83.61%和68.84%~82.95%。此外,5%丁虫腈EC和30%茚虫威WG分别对二化螟和稻纵卷叶螟高效,而20%三唑磷EC、40%水胺硫磷EC、29%杀虫双AS和240g/L甲氧虫酰肼SC难以有效控制二化螟和稻纵卷叶螟危害。在水稻生产实践中,建议轮换使用双酰胺类和大环内酯抗生素类杀虫剂、乙基多杀菌素和氰氟虫腙防治二化螟和稻纵卷叶螟。     

Interactions between the striped stem borer Chilo suppressalis (Walk.) (Lep., Pyralidae) larvae and rice plants in response to nitrogen fertilization

A screenhouse experiment was conducted to examine the damage and compensation in rice plants when injured by the striped stem borer, Chilo suppressalis (Walker), larvae at tillering stage, as well as larval survival and development of the insect at different nitrogen (N) fertilization levels. Potted plants were fertilized at late seedling stage at the rates 0, 200, 400, 600 and 800mgN/pot, respectively. More deadheads were caused as fertilization increased. Plants compensated well for injury at the fertilization concentrations of 200 and 400mgN/pot by producing new tillers, but such compensation did not take place at 600 and 800mgN/pot. Two weeks after infestation, the highest number of remaining healthy tillers was found in plants fertilized at 400mgN/pot. Larval survival varied little among the treatments 200 to 800mgN/pot. Larval weight attainment and/or developmental rate increased with increasing fertilization level from 200 to 600mgN/pot, but both declined rapidly as fertilization reached 800mgN/pot, indicating the great dependence of plant suitability on N fertilization levels. Conclusively, both the compensation response of rice plants and their suitability for C. suppressalis larvae could be significantly affected by N fertilization levels.     

Interactions between the striped stem borer Chilo suppressalis (Walk.) (Lep., Pyralidae) larvae and rice plants in response to nitrogen fertilization

A screenhouse experiment was conducted to examine the damage and compensation in rice plants when injured by the striped stem borer, Chilo suppressalis (Walker), larvae at tillering stage, as well as larval survival and development of the insect at different nitrogen (N) fertilization levels. Potted plants were fertilized at late seedling stage at the rates 0, 200, 400, 600 and 800mgN/pot, respectively. More deadheads were caused as fertilization increased. Plants compensated well for injury at the fertilization concentrations of 200 and 400mgN/pot by producing new tillers, but such compensation did not take place at 600 and 800mgN/pot. Two weeks after infestation, the highest number of remaining healthy tillers was found in plants fertilized at 400mgN/pot. Larval survival varied little among the treatments 200 to 800mgN/pot. Larval weight attainment and/or developmental rate increased with increasing fertilization level from 200 to 600mgN/pot, but both declined rapidly as fertilization reached 800mgN/pot, indicating the great dependence of plant suitability on N fertilization levels. Conclusively, both the compensation response of rice plants and their suitability for C. suppressalis larvae could be significantly affected by N fertilization levels.     

庐江县稻飞虱群落演变特点、大发生原因及防治对策

通过分析历史资料、调查研究及田间试验,归纳了安徽省庐江县稻飞虱群落演变规律,分析了2006年褐飞虱发生特点、大发生成因,并提出相应的防治对策。1964年以来稻飞虱群落演变规律可分为4个阶段,其间相对于白背飞虱,褐飞虱种群数量分别为高、低、平、高水平,总态势近于“U”字形。当前褐飞虱发生特点主要有迁入虫源早、迁入量大,种群增量大,危害时间长,危害世代多,危害面积广。回升和暴发可能的原因包括水稻品种、作物布局和栽培措施改变,秋季气温升高,褐飞虱对吡虫啉产生抗药性,害虫天敌下降,以及农民防治组织缺乏。防治对策强调改进虫情测报、适时早治、适当多治、选用正确药剂、改进施药方法,并建立健全基层防治组织。     

影响禾谷缢管蚜自然种群变动的关键因素研究

试验表明 ,影响禾谷缢管蚜自然种群变动的主要因素是气候和天敌。低龄若蚜主要受风雨的影响 ,高龄若蚜和成蚜主要受天敌和风雨共同作用。天敌主要为七星瓢虫和食蚜蝇。禾谷缢管蚜是典型的γ对策昆虫 ,具有较高的内禀增殖率 ,又具有较高的死亡率。种群的变动受自身密度的影响 ,γ值的大小可以说明自然种群变化的趋势     

Laboratory studies on the influence of the earthworm Eukerria saltensis (Beddard) (Oligochaeta: Ocnerodrilidae) on overlying water quality and rice plant establishment

Dense infestations of a peregrine oligochaete worm, Eukerria saltensis (Beddard), have been linked to rice crop failures in southern New South Wales, Australia. The influence of E. saltensis on water quality and rice plant establishment was investigated in a series of laboratory experiments using a flooded Riverina clay soil. Worm densities of 20 and 40 per container (2548 and 5096 worms/m², respectively) significantly increased water turbidity after 7 days incubation. Longer incubation periods led to turbidity levels of over 500 NTU being achieved (40 worms per container, 21 days incubation). Water pH was significantly reduced by densities of 10, 20, and 40 worms per container after 7 days under cyclical illumination, however in continuous darkness significant changes in pH related to worm density were only found after 21 days incubation. Nitrogen as NH₄+ and total phosphorus increased significantly in the overlying water in response to increasing worm densities after 21 days incubation, however nitrogen as nitrate/nitrite and soluble phosphorus did not. Algal production (measured as extracted chlorophyll a concentration) was unaffected by the worms, reflecting the low concentrations of available phosphorus in all treatments. Rice plants grown in containers with worms produced significantly longer and heavier shoots than control plants. Root systems were unaffected, and there was no evidence of root abrasion. Evaluation of rice seed stratification in the soil profile indicates that rice seeds can be passively transported below the soil surface by the feeding and tunnelling activity of E. saltensis. Our results suggest that E. saltensis impedes the establishment of aerially-sown rice crops primarily by increasing water turbidity. Plants respond to high turbidity by partitioning more of their growth into shoot production, and consequently become vulnerable touprooting through wave action, particularly as the soil loses compaction because of worm activity. Maintaining the lowest possible water levels during rice crop establishment has helped farmers to minimize these effects.     

Characterization of glutathione S-transferase of the rice leaffolder moth, Cnaphalocrocis medinalis (Lepidoptera: Pyralidae): Comparison of its properties of glutathione S-transferases from other lepidopteran insects

An enzyme that possesses the glutathione S-transferase (GST) activity was found in the rice leaffolder moth, Cnaphalocrocis medinalis. The enzyme was purified to homogeneity for the first time by ammonium sulfate fractionation and affinity chromatography. The resultant enzyme revealed a single band with a molecular mass of 24 kDa by SDS-polyacrylamide gel electrophoresis under reduced conditions. When assayed with 1-chloro-2,4-dinitrobenzene, a universal substrate for GST, the purified GST had an optimum pH at 8.0, and was fairly stable at pH 3-10 and at temperatures below 50 °C. The enzyme was also able to conjugate glutathione to 4-hydroxynonenal, a cytotoxic lipid peroxidation product. The present GST was inhibited by fenitrothion, permethrin, and deltamethrin, suggesting that the GST could be involved in metabolizing these organophosphorus and pyrethroid insecticides.     

四川省犍为县越冬代稻显纹纵卷叶螟冬后虫口密度和生物学特性

稻显纹纵卷叶螟Cnaphalocrocis exigua(Butler)是稻纵卷叶螟Cnaphalocrocis medinalis(Guenée)的近缘种,目前主要在我国西南稻区发生为害。为了明确稻显纹纵卷叶螟在四川省犍为县冬后的虫源状况,我们开展了稻显纹纵卷叶螟冬后虫源结构调查,观察了冬后种群的生物学特性,并研究了温度对其的影响。结果显示,犍为县舞雩乡和罗城镇稻显纹纵卷叶螟冬后虫源密度分别为7.09头/25丛和5.50头/25丛。调查时稻显纹纵卷叶螟主要以蛹为主,有少量幼虫。稻显纹纵卷叶螟越冬代雌雄蛹重分别为11.56 mg和11.82 mg,性比(雌∶雄)为1.29∶1,蛹被寄生率为16.5%。20℃、22℃、24℃和室温下稻显纹纵卷叶螟越冬代蛹羽化率分别为44%、38%、52%、43%。不同温度下,稻显纹纵卷叶螟产卵量及成虫寿命无显著差异。本研究结果对于开春稻显纹纵卷叶螟的防控具有指导意义。     

氮肥对水稻叶冠层捕食性天敌种群及其自然控制能力的影响

为了公正地评价氮肥对整个稻田生态系统的影响，在国际水稻研究所试验场分别设立0、100和200kg／hm^2三个氮肥水平，测定了水稻主要特性参数和叶冠层捕食性天敌的种群动态，同时以果蝇蛹作为替代猎物的方法在田间模拟评价了叶冠层捕食性天敌对害虫的自然控制能力。结果表明，虽然施用200kg／hm^2氮肥稻田的稻株高度、叶面积和稻草干重显著比施用100kg／hm^2氮肥稻田的高，但每丛分蘖数和稻谷产量则没有明显差异。在水稻叶冠层中，肖蛸、圆蛛、黑肩绿盲蝽、稻红瓢虫和捕食性螅等为稻飞虱主要捕食性天敌。肖蛸在水稻孕穗期的数量最高，圆蛛的种群随水稻的生长而下降，但黑肩绿盲蝽、稻红瓢虫和捕食性螅的数量却均随水稻的生长而增加。施用氮肥后稻田中肖蛸和稻红瓢虫的种群数量显著减少。在水稻孕穗期，叶冠层上蜘蛛网的数量和蜘蛛网总面积均随氮肥施用量的提高而显著减少。在水稻孕穗期和乳熟期，不施用氮肥稻田中的捕食性天敌对替代猎物果蝇蛹的捕食能力显著高于其它两个施用氮肥的稻田中的捕食能力。而在乳熟期施用100kg／hm^2氮肥稻田的捕食能力又显著比施用200kg／hm^2氮肥稻田的高。结果说明过量施用氮肥可削弱天敌对害虫的自然控制作用。     

水稻条纹叶枯病发生规律与防治技术研究

通过多点同时系统调查,明确在新的种植形势下常州市灰飞虱和水稻条纹叶枯病的发生规律。在试验研究基础上,提出了麦田狠治灰飞虱、药剂浸种、秧田适期喷药等水稻条纹叶枯病的药剂“治虫防病”措施,经实际应用,两年来成效显著。     

杂交水稻穗期三化螟侵入部位及防治技术探讨

2a的试验调查表明,杂交水稻穗期三化螟的侵入以穗茎部和倒一节为主,穗部以下各节也可侵入;三化螟有转移为害习性;在大发生年,杂交水稻穗期三化螟必须防治两次,第一次防治适期应以卵孵始盛至卵孵高峰期为宜,间隔5～7d后防治第二次。