666对中稻田二代二化螟幼虫的防治试验

在我国南方早中稻地区,用666防治一代二化螟的效果很好。但用于防治二代二化螟的效果往往不够稳定。为此,我们在中籼稻田进行了以下试验: 在二代螟卵孵化基本结束、田间有各龄幼虫时,用666处理稻田(用6％666粉剂),试验分不同用药量及不同施药方法两组处理,共11个小区,小区面积0.3亩,施药后3天检查田间各龄幼虫死亡率,结果如表1     

温州市第三代二化螟大发生原因分析

第 3代二化螟大发生是由防治第 2代时失去最佳防治适期 ,而使其绝大部分幼虫存活下来 ,成为第 3代有效虫源所致 ;二是发生时间早 ;三是早稻收割期天气差 ,使 2代向 3代的转化率提高。1998温州市第 3代二化螟大发生正是由于上述 3个原因综合的结果 ,发生面积达 13.5万公顷 ,占当年晚稻面积的 95%以上 ,防治面积达 18万公顷 ,为该市近 10年来所少见。     

Bt与锐劲特混用防治水稻二化螟的效果评价

Bt与锐劲特混用对水稻二化螟有较显著的防治效果。每 667m2 用Bt2 5g加锐劲特 1 5mL ,防治第 1 ,3代二化螟 ,适期在 2～ 3龄幼虫盛期 ,一般情况下 1次施药即能控制全代二化螟的危害     

稻田养鸭对稻鸭复合系统中病、虫、草害及蜘蛛的影响

研究鸭子在稻鸭复合生态系统中对蜘蛛及病、虫、草害的影响。试验结果表明 :稻田中放入 4 5 0只鸭 / hm2 ,对农田杂草的控制率为 98.8% ;稻鸭共栖小区蜘蛛数量显著高于施药小区。高峰期蜘蛛量 ,稻鸭共栖小区比施药小区高 6 3.6 % ;第 4、第 5代稻飞虱虫量稻鸭共栖小区比对照小区分别下降 4 7.6 %、72 .8% ,稻鸭共栖对稻飞虱可以起到稳定、持续的控制作用 ;可减轻二化螟、纹枯病的发生量和发病程度约 5 0 .0 % ,对二化螟和纹枯病有较好的控制效果 ;稻鸭共栖对纵卷叶螟控制效果较差 ,水稻生长后期需结合采用药剂防治 ;稻鸭共栖可改变农田害虫、天敌的生存环境 ,减少用药次数 ,减轻农药对环境的污染 ,提高水稻产量和经济效益     

三唑磷防治咖啡木蠹蛾的初步研究

咖啡木蠢蛾在福建省1年发生2代,幼虫的孵化高峰期分别发生在6月与10月,掌握其幼虫孵化高峰期适时喷施20％三唑磷乳油1500倍稀释液,结果表明,对药前10d内孵化已蛀枝干的幼虫杀虫率为90oA～100％,对药后10d内已蛀枝干的幼虫杀虫率为85％～100％,2次施药就能有效防治咖啡木蠢蛾为害。由于此法简便,经济,易行,故建议在生产上可以推广应用。     

三种药剂对早稻二化螟的防效及施药适期探讨

试验结果表明,氯虫苯甲酰胺、氯虫·噻虫嗪有对二化螟Chilo suppressalis(Walker)有较好的防效和较长的持效,一次施药可兼治多个峰次。20%氯虫苯甲酰胺150mL/hm2、40%氯虫·噻虫嗪120g/hm2和2.15%甲氨基阿维菌素苯甲酸盐750mL/hm2在二化螟2龄幼虫高峰期施药,药后8d对幼虫防效分别达94.7%、91.2%和91.0%;药后18d的防效依次为99.0%、98.0%、73.2%,氯虫苯甲酰胺、氯虫·噻虫嗪处理防效仍高于药后8d,但甲氨基阿维菌素苯甲酸盐处理防效明显下降;药后18d对主峰保苗效果(枯心)氯虫苯甲酰胺和氯虫·噻虫嗪分别为99.0%、98.0%,甲氨基阿维菌素苯甲酸盐处理偏低,为73.2%。对后峰保苗效果(枯鞘)氯虫苯甲酰胺为84.9%好于氯虫·噻虫嗪处理的69.3%,甲氨基阿维菌素苯甲酸盐的防效仅为7.1%。氯虫·噻虫嗪不同时期施药处理后,主峰卵孵高峰后14d考查,防治效果和保苗效果以卵孵高峰施药最好,其次为2龄幼虫高峰期施药;主峰卵孵高峰后24d考查,主峰卵孵高峰至3龄幼虫高峰施药对主峰均有较好的防效,但对后峰的防效,随着施药时间推迟而提高,但在螟虫重发地区施药过迟,前期的大量枯鞘会影响稻苗生长与分蘖。因此作者建议在二化螟发生量大、后峰数量多地区,采用主峰卵孵高峰和后峰卵孵高峰2次防治对策,在螟虫发生较轻、后峰数量较少或全代发生较为集中地区,可根据当地虫情发生情况,适当推迟施药,达到一次用药,解决全代螟害。甲氨基阿维菌素苯甲酸盐持效期较短,可根据螟虫发生峰次施用。     

2010年广西兴安地区稻纵卷叶螟发生动态及迁飞轨迹分析

稻纵卷叶螟是我国水稻上的重要害虫,近年来给我国水稻生产造成严重的损失。兴安地区位于广西东北部是每年稻纵卷叶螟在我国南北往返的必经之路,分析该地区稻纵卷叶螟的种群动态和迁飞规律,对全国稻纵卷叶螟的预测预报和防治工作意义重大。采用灯光诱捕、田间系统调查与雌蛾卵巢解剖的方法研究了2010年广西兴安地区稻纵卷叶螟的发生动态和世代虫源性质,并运用大气质点轨迹分析平台HYSPLIT和气象图形处理软件GrADS对2010年广西兴安地区稻纵卷叶螟迁飞高峰期进行了迁飞轨迹和气象背景分析。结果表明:(1)稻纵卷叶螟种群数量在广西兴安地区随季节变化明显,年发生6代,于4月底迁入,迁飞活动主要集中在5月下旬-8月中旬。在双季早稻田、单季中稻田和双季晚稻田均发生3代,且在不同类型田中重叠发生,其在双季早稻田的发生量明显高于单季中稻田和双季晚稻田。(2)明确了兴安地区稻纵卷叶螟各世代虫源性质。第2、3代主害双季早稻,均为迁入虫源;第4代数量最多,主害双季早稻,属于迁入虫源在本地繁殖世代;7月中下旬连续降雨天气阻碍第四代稻纵卷叶螟从本地迁出,滞留单季中稻为害。第5代主害单季中稻,虫源性质复杂,主要为本地虫源本地繁殖型,既有迁入,又有迁出;第6代前期主害单季中稻,后期主害双季晚稻,第7代为害双季晚稻,虫源性质均为本地虫源大部迁出型。(3)2010年广西兴安5月上旬稻纵卷叶螟迁入虫源地来自广东沿海阳江和湛江稻区,6月中旬大规模迁入虫源地主要来自广东沿海雷州半岛稻区。低空激流为稻纵卷叶螟的迁入提供了运载气流,而当时的降雨是迫使稻纵卷叶螟集中降落的主要原因。10月中旬从本地迁出的稻纵卷叶螟,随东北气流南下可到达广西沿海北海市。     

晚稻中后期二化螟为害特点及严重发生原因剖析

近年来 ,浙江省仙居县晚稻中后期二化螟ChilosuppressalisWalker为害日趋严重。分析原因 ,一是单季稻等桥梁田面积的不断扩大 ,使 8月底至 9月上旬田间出现了全年发生量最大的 2代主蛾峰 ,卵孵化盛期与连作晚稻抽穗期吻合 ;二是冬春气温升高 ,发生期提早 ,2代虫源寄主、水稻移栽期等的多样化 ,使 3,4代发生期拉长 ;三是因 3代主峰和 4代的螟害发生具有“隐性”的特点 ,其测报和防治工作被忽视 ;四是二化螟对常用药剂的抗药性提高。据此提出了相应的治理对策     

转Cry1Ab和Cry1Ac融合基因型抗虫水稻对田间二化螟和大螟种群发生动态的影响

以Bt水稻华恢1号(Cry1Ac和CryAb融合基因;简称HH1)及其对照亲本明恢63(简称MH63)稻田靶标害虫二化螟Chilosuppressalis和次靶标害虫大螟Sesamia inferens为研究对象,研究了转基因抗虫水稻大田螟虫发生规律及其靶标和次靶标害虫致害力差异。结果表明,Bt水稻及其对照亲本上二化螟或大螟的卵块数量差异不显著,同时,对照亲本上二化螟与大螟的落卵量差异不显著,但Bt水稻上二化螟的落卵量显著大于大螟。与对照亲本相比,Bt水稻上二化螟幼虫发生量显著降低,降幅高达84.9%—100%,但大螟发生量差异不显著;此外,对照亲本上二化螟幼虫发生量显著高于大螟,但Bt水稻上两者差异不显著。同时,Bt水稻上二化螟导致的枯心/白穗率和受害丛率都显著低于其在对照亲本上的致害程度,降幅分别为30.8%—98.3%和11.4%—96.6%,而大螟差异不显著。可见,Bt水稻对靶标害虫二化螟具有较高抗性,而对次靶标害虫大螟的抗性不明显。另一方面,Bt水稻和对照亲本上二化螟导致的枯心/白穗率和受害从率都显著高于大螟。可见,二化螟仍是当前非转基因水稻上的主要害虫,而Bt水稻对二化螟幼虫发生的显著抑制作用以及对大螟幼虫发生的不显著影响,使得其大面积商业化种植下靶标害虫二化螟和次靶标害虫大螟间的竞争替代成为可能。     

耕作制度与水稻品种对二化螟发生世代的影响

探讨了我县耕作制度与水稻品种的变化对二化螟发生世代及危害程度的影响。双季杂交水稻的大面积种植,一是使早稻的播、插期提早,二化螟第1、2代发生期也相应提早,发生量与危害程度转轻;二是杂交早稻为2代安全过渡创造了条件。提高2代转化率,导致晚稻上第3代发生期提早、危害加重;三是杂交水稻改善了二化螟的营养条件,加速幼虫发育,促进世代的转化。     

Stage-specific population dynamics of cottony cushion scale,Icerya purchasi (Hemiptera: Monophlebidae), in citrus orchards in Jeju,Korea

The cottony cushion scale, Icerya purchasi Maskell (Hemiptera: Monophlebidae), is a polyphagous, cosmopolitan and destructive pest of citrus. This study was conducted to obtain the stage-specific phenology of I. purchasi for seasonal management strategies in the field. Movement of crawlers (hatched nymphs) in egg sacs of overwintered females started in late May, peaked in early to mid-June, and was completed by late June. Generally, the 1st generation occurred from late May until late September and the overlapping second generation occurred from early September. The 1st nymphs in the 1st generation peaked in mid June. The 2nd nymphs showed peak activity in late July. The 3rd nymphs showed peak population in early September. The 1st generation adults peaked in mid September. In the 2nd generation, the 1st nymphs peaked in early October, the 2nd nymphs showed peak activity in late October, and the 3rd nymphs reached a plateau after mid October. The 2nd generation adults occurred from late October. Consequently, two life cycles were competed in the Jeju area. The average fertilities of I. purchasi were 623 and 247 crawlers per female in overwintered and summer generations, respectively. An average of 20.7% of all citrus orchards was infested with I. purchasi, with a mean of 3.9% infested trees in Jeju. These results should be useful in establishing management strategies for I. purchasi in citrus orchards.     

Life tables and population parameters of the green leafhopper,Nephotettix cincticeps (Uhler), in the southwestern district of Japan with special reference to the first generation on foxtail grass

The three year (1988–1990) life tables of Nephotettix cincticeps were constructed, and the daily survival rate and longevity of female adults were estimated by Hokyo and Kiritani's (1967) method for the overwintering and the first-generations on the foxtail grass in Okayama, southwestern Japan. The life tables and the population parameter values estimated were compared with those in the other generations on rice. The FARMCOP suction sampler was employed to survey the population density. The durations of pre-ovarial maturation of female adults of the 1st generation on foxtail grass and rice seedling were similar. Longevity of adults of the overwintering and the first generations which emerged on the wild host was longer than that of the other generations (2nd and 3rd generations) on the rice plants. Fecundity of females decreased successively as the generation proceeded and it became lowest in the final 3rd generation. Only about 3.5 percent of first-instar nymphs of the 1st generation emerged as adults in the fallow field. The survival rate of nymphs on foxtail grass was always lower in comparison with that on rice plants. However, the survival rates of nymphs on foxtail grass and rice seedling were not significantly different from each other under laboratory conditions. In the fields, senescence of foxtail grass occurred in the midst of nymphal period of the 1st generation. The survival rate of nymphs on foxtail grass decreased with the increasing in the nymphal density. Abundance of spiders during the 1st generation was higher than that in the early stage of rice plants.     

白背飞虱的迁飞生物学:安徽潜山个例分析

通过田间系统调查与雌虫卵巢系统解剖研究了2008—2010年潜山混作稻区白背飞虱Sogatella furcifera (Horváth)的种群动态以及各发生世代的虫源性质,并结合2005年以来的灯诱及田间普查资料分析了造成不同年份白背飞虱种群消长态势差异性的主要原因。结果表明:(1)第3、4代白背飞虱分别在8月初和9月上中旬有2个发生高峰期,其中第3代主害单季中稻,第4代主害双季晚稻。(2)单季中稻和双季晚稻田白背飞虱各发生世代的虫源性质有所不同,中稻田四(2)代后期、五(3)代前期属于本地滞留、部分迁出,五(3)代后期属于大部迁出、少量滞留为害;而晚稻田五(3)代后期为基本迁入型,六(4)代前期为本地繁殖、少量迁出型,六(4)代后期大部迁出。(3)前期迁入虫量会影响田间2、3代种群数量,中稻田第3代滞留虫量的多少是影响双晚田后期发生量的重要因素,而降雨、温度等气象因子则是影响主害代(第3代)种群迁出与滞留的关键因子。     

2008年永福县早稻田稻纵卷叶螟发生动态及虫源性质

2008年通过调查和雌蛾卵巢解剖研究广西区永福县早稻田稻纵卷叶螟Cnaphalocrocis medinalis(Guenée)的发生动态和田间种群的虫源性质。结果表明,稻纵卷叶螟在永福县早稻田可发生4代。稻纵卷叶螟第1、2代属于基本迁入型;第3代性质较为复杂,属于本地繁殖型,既有迁入又有迁出;第4代为本地繁殖、大部分迁出型。对暴雨期间稻纵卷叶螟田间蛾量消长的研究表明,短时期的暴雨水淹对全县稻纵卷叶螟的田间蛾量消长总的影响不明显,但不同水淹情况的田块间虫量存在显著差异。还分析讨论2008年永福县早稻田稻纵卷叶螟暴发成灾的原因。     

真水狼蛛的生物学和田间种群动态研究

真水狼蛛在湖北武汉1a发生3个不完整的世代,以第2代历期最短,第3代(越冬代)历期最长。主要以亚成蛛越冬。雌、雄均可多次交配。真水狼蛛1生最多可产4个卵袋,平均2.8个,含卵量较大(平均90粒)。雌蛛有较强的护卵、护幼习性。卵的孵化率较高,平均孵化率为91.36％。真水狼蛛共蜕皮6次,有7个龄期。性比各个世代均为雌蛛多于雄蛛。真水狼蛛捕食叶蝉、飞虱等多种水稻害虫,捕食量与龄期、蜕皮和性别有关。真水狼蛛在6月5日左右开始由田埂向稻田内迁移,1a有2个发生高蜂,分析了影响真水狼蛛种群动态因素。     

中晚粳稻区褐飞虱防治策略的研究

为了解二代褐飞虱对粳稻的为害损失,确定合理的防治指标和防治策略,为科学使用噻嗪酮、吡虫啉等药剂防治稻飞虱提供依据,作者在武育粳３号上,通过接不同的虫量,并进行笼罩的方法,研究了二代褐飞虱的增殖规律和为害损失及防治指标。并进行了锐劲特防治不同世代褐飞虱策略试验。结果表明,不同水稻生育期,不同虫口密度的褐飞虱的增长速度不一样;在水稻同一生育期,低密度的增殖速度要大于高密度,但总虫量高密度区显著高于低密度区。二代褐飞虱百丛虫量与水稻产量损失呈极显著正相关（ ｒ＝ ０．９５７６**）,关系式为 ｙ＝－ １８．３３０２＋ １０． ２８９２ｌｇｘ（ｘ为 ８月上旬褐飞虱百丛虫量）,防治指标为 １１０－１２０头。因此,在早发年,迁入量较大的年份必须采取“治二压三控四”的策略,１９９６－１９９７年全面推广这一策略,成效显著。     

湖北江汉稻区优质香稻上二化螟的为害特性

研究了二化螟Chilo suppressalis(Walker)对优质香稻鄂香1号和武香988及优质常规中稻鄂中5号的田间为害特性。结果显示,1代二化螟危害造成的枯心苗数优质香稻略低于优质常规中稻。2代二化螟危害造成的枯孕穗和白穗优质香稻鄂香1号低于常规中稻,平均每15丛7.91株。田间剥查发现优质香稻中4~5龄2代二化螟所占百分比高于常规中稻,武香988中2代二化螟蛹所占比例高于常规中稻,达46.51%。3代二化螟量优质香稻低于常规中稻。结果说明香稻受二化螟的危害集中在2代,因而香稻二化螟的防治应注意消灭1代老熟幼虫和2代幼虫。     

Seasonal Development and Population Fluctuations of Arrowhead Scale,Unaspis yanonensis (Homoptera: Diaspididae), in Citrus orchards in Jeju,Korea

Arrowhead scale, Unaspis yanonensis (Kuwana), feeds on the foliage, stems, and fruits of citrus trees, and causes tree dieback when heavy infestations occur. The objective of this study was to collect basic data to establish seasonal management strategies for U. yanonensis. The abundances of male nymphs and female adults were monitored in unsprayed citrus orchards. The overwintered females started to produce their progenies (1st gen.) from mid-May. The populations of the 1st nymphs in the 1st generation showed a bimodal occurrence pattern, with a 1st larger peak between late May and early June, and a 2nd smaller peak in June. The nymphs in the 2nd generation, which were laid from newly developed females, were observed from late July, and the 1st peak occurred in mid-August, followed by an obscure later peak (the 2nd peak) around late September. The numbers of live females for the overwintered populations began to decrease gradually from early June by the impact of the predacious Chilocorus kuwanae, as well as by natural mortality factors, and dropped to a low level in mid-July. When there were abundant predator attacks, the U. yanonensis female populations sharply decreased from early June and were almost nonexistent in July. New female adults (1st generation adults) appeared from late June and peaked in mid-July. The 2nd generation female adults, consequently, the overwintering generation, occurred from mid- September, and gradually increased to late October. Overall, these results will be useful in terms of management strategies for U. yanonensis in citrus orchards.