越冬代棉大卷叶螟的种群动态

对棉大卷叶螟Sylepta derogata Fabricius第5代、第6代室内种群饲养结果显示,该虫的有效越冬虫源为第5代滞育的老熟幼虫,滞育率24.4%～33.1%,第6代棉大卷叶螟的发生对第2年的种群基数影响不大。滞育老熟幼虫的越冬存活率为60.0%～71.9%。次年越冬代羽化的成虫雌虫少,雄虫多,单雌产卵量平均为163.4～198.8粒。     

棉铃虫室内饲养技术的改进

在传统人工饲料饲养技术的基础上 ,对棉铃虫的卵、幼虫、蛹和成虫的饲养器材和操作方法进行了简化和改进。将产于纱布上的卵经消毒晾干后 ,直接放于塑料保鲜袋中孵化。初孵幼虫用毛笔移入特制的带盖 1 0孔饲养盒 ,每孔 1头 ,孔径和高度为 2 5cm× 1 8cm ,接虫前每孔加人工饲料 4～ 5g ,接虫后加盖 ,直至化蛹。幼虫化蛹后用培养皿收集 ,直接放于成虫饲养笼中 ,任其羽化、交配和产卵。采用这一改进饲养技术 ,幼虫存活率、化蛹率、羽化率等均有显著提高 ,棉铃虫的病害明显减少 ,同时节约饲养成本约 5 0 %。     

转Bt基因棉花国抗62对棉铃虫生长发育的影响及田间抗虫效果

为了明确新疆第一个自主转Bt基因棉花品种国抗62对棉铃虫Helicoverpa armigera生长发育影响及田间抗虫效果,2005年进行了室内生物测定和田间小区试验。在室内以国抗62（转Cry1Ac基因棉花）和中棉35（对照常规棉花）的叶片饲喂棉铃虫幼虫,从幼虫发育历期、体重、存活率、化蛹等方面,分析了棉铃虫生长发育动态。结果表明,国抗62对棉铃虫生长发育的抑制作用非常显著。与对照相比,取食国抗62的棉铃虫幼虫1～6龄龄期分别延长了1.0,7.8,8.2,17.8,20.3和＞21.3天;幼虫发育到6龄时存活率仅为2.6%,最终无一化蛹,而对照幼虫发育到6龄时存活率为91.8%,最终化蛹率为89.8%。田间小区调查结果显示国抗62对第2代棉铃虫有非常好的抗虫效果：两个品种棉田棉铃虫落卵量无显著差异,但国抗62棉田比对照棉田虫口数量降低85.7%,顶尖被害率降低94.4%,蕾铃被害率降低95.1%,差异达到显著和极显著水平。但国抗62对第3代棉铃虫的田间抗虫效果欠佳。棉铃虫在新疆棉田以第2代为害为主,因此,国抗62能够起到有效的控制作用。     

甜菜夜蛾人工饲料及饲养技术研究

研究了人工继代繁殖甜菜夜蛾饲料配方及饲养方法 ,测定了各虫态发育历期、幼虫死亡率、化蛹率、羽化率、蛹畸形率及不同世代蛹重。采用改进的饲料配方饲养的深圳种群 ,第 2代幼虫死亡率、化蛹率、蛹畸形率、羽化率分别为 7 8% ,97 3 % ,2 7%和 93 8% ,第 2 ,5 ,9,1 2代平均单头蛹重分别为 1 1 9 7± 1 6 1 ,98 3± 1 1 4,94 3± 1 2 6和 82 4± 9 6mg,平均单雌产卵量分别为 1 1 3 7 2± 63 3 ,684 5± 5 3 7,45 6 9± 40 2和 3 91 7± 45 6粒。人工饲养的甜菜夜蛾 ,卵、幼虫、蛹、雌性成虫的发育历期分别为 2 5～3 5 ,1 0～ 1 2 5 ,7～ 8 5和 8～ 1 4天 ,完成一个世代需要 2 1～ 2 5天。     

沙雷氏杆菌S3菌株产几丁质酶对棉铃虫不同虫龄幼虫的后致死作用

研究了粘质沙雷氏杆菌（Serratia marcesens）S3菌株产几丁质酶（Chitinase）对棉铃虫(Helicoverpa armigera)的后致死作用。生物测定表明,沙雷氏杆菌S3菌株产几丁质酶对棉铃虫幼虫48h的毒力不高,其中几丁质酶浓度为50μg/mL对初孵幼虫的毒杀力仅为8.3%,对高龄幼虫48h不表现毒力。但几丁质酶对棉铃虫幼虫特别是低龄幼虫生长发育如10d龄虫重、蛹重、化蛹历期、蜕皮、羽化等影响较大,造成棉铃虫幼虫化蛹历期延长,死蛹率和不正常羽化率增加。其中经几丁质酶处理后的初孵、1d龄、2d龄、3d龄、4d龄幼虫蛹重分别是对照组的51.0%、77.1%、81.4%、86.0%、96.2%;化蛹率分别为74.5%、87.5%、93.7%、95.8%、95.8%,都低于对照组的97.9%;死蛹率分别为57.3%、18.8%、13.6%、7.8%、7.9%;初孵幼虫化蛹历期长达14d;初孵幼虫的正常羽化的蛹只有40.8%。几丁质酶对棉铃虫的后致死作用明显。     

黄连木种子小蜂的生物学特性和发生规律

通过田间及室内饲养观察,黄连木种子小蜂EurytomaplotnikoviNikolskaya在河南省太行山区为1年发生1代,以老熟幼虫在被害果内过冬。翌年4月中旬开始化蛹,5月下旬至6月上旬为成虫羽化产卵的盛期。幼虫5月中旬开始孵化,在果内取食至8月中、下旬老熟越冬。成虫在果壳内停留4～5d,出壳后成虫寿命:雄虫3～7d,雌虫4～17d,产卵前期3.7d。平均产卵量35.4粒,卵期3～4d。幼虫共5龄,预蛹期4～5d,蛹期8～10d,蛹期发育过程中形态变化的阶段性分为4级。成虫交尾产卵的最适温度为23～25℃,化蛹、羽化较适宜的湿度为65%～70%。     

人工饲养棉铃虫环境条件的研究

<正> 我们就人工饲养棉铃虫过程中,温度、湿度和光照等三大要素对棉铃虫各虫态的影响进行过一些研究,现将资料整理报告于后。 材料与方法 棉铃虫Heliothis armigera Hbner虫源是从大田采回的越冬老熟幼虫,室内化蛹羽化的成虫繁殖的后代。 饲养室温度、湿度用电热蒸气和喷水控制在25—30℃之间,相对湿度70—85％,光照以30瓦或40瓦日光灯为光源,距0.5—2.0米,光     

山东省亚洲玉米螟越冬特性及越冬代成虫发生期预测

【目的】亚洲玉米螟Ostrinia furnacalis(Guenée)是我国玉米生产上的重要害虫。亚洲玉米螟越冬特性及预测预报的研究,对于提高防治效果具有重要意义。【方法】本文通过对山东省东昌府、曲阜、商河、滨城区、即墨和栖霞地区玉米秸秆和穗轴进行剖查,统计越冬幼虫虫量和位置分布。并将幼虫带回济南放于室外待其化蛹,统计化蛹时间及存活率。【结果】山东省6个地区2007年春季玉米秸秆和穗轴中亚洲玉米螟平均越冬虫量分别为41.80头/百秆和19.91头/百穗,其中在玉米秸秆中越冬虫量占总量的67.30%。越冬幼虫在玉米秸秆上、中和下部比例分别为21.18%、38.80%和40.02%。越冬代亚洲玉米螟化蛹始盛期、高峰期、盛末期分别为5月27日、6月5日和6月21日,预测越冬代羽化始盛期、高峰期和盛末期分别为6月8日、6月17日和7月1日。【结论】应重视对亚洲玉米螟越冬虫源的控制,及时处理玉米秸秆和穗轴,第一代幼虫应该在6月中下旬防治,第二代应该在7月中旬防治。     

茴香薄翅野螟发生动态的调查

经调查研究表明:在青海省的油菜种植区,茴香薄翅野螟Evergestis extimalis Scopoli越冬幼虫从6月初开始化蛹,6月中旬化蛹率达为80%,到6月下旬化蛹率达到100%;成虫于7月上旬开始羽化,7月15～20日为成虫羽化高峰;田间卵始见期为6月下旬至7月上旬,7月中旬达到产卵高峰期;越冬幼虫平均死亡率为96.63%。     

印楝素A和印楝素B对棉铃虫生长发育的影响

为了明确印楝素A和印楝素B生物活性的差异,选用印楝素A和印楝素B对棉铃虫生长发育的影响进行了比较研究。结果表明:印楝素A和印楝素B对棉铃虫3龄幼虫具有良好的拒食活性,5μg/mL处理48 h对棉铃虫3龄幼虫的拒食率分别为85.17%和69.02%。分别用含有药剂(1μg/mL)的饲料饲喂棉铃虫5龄幼虫,结果表明:印楝素A和印楝素B能够明显抑制棉铃虫5龄幼虫的体重增长,处理14 d后幼虫的体重分别下降50.28%和43.08%,仅有少量个体化蛹,化蛹率分别为26.67%和13.33%。进一步的羽化结果表明:经印楝素A和印楝素B处理的虫蛹均未能完成羽化。综合各阶段试验结果来看,印楝素A和印楝素B的生物活性存在差异,印楝素B对棉铃虫生长发育的抑制作用高于印楝素A。     

Effects of transgenic Bt cotton on overwintering characteristics and survival of Helicoverpa armigera

The effects of transgenic Bt cotton on the overwintering generation of the cotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), are unknown. We hypothesized that a Bt cotton diet may adversely affect fitness of this generation and examined fresh weight, lipids, glycogens, low-molecular-weight sugars and SCPs (supercooling points) of pupae, as well as survival of larvae, diapausing pupae and adult emergence in comparison with controls. Field and laboratory experiments showed that larvae fed on Bt cotton had a decreased pupation rate, and fewer entered diapause and emerged as adults compared with larvae fed non-Bt cotton. Furthermore, larvae fed Bt cotton had reduced pupal weight, glycogen content and trehalose levels both in diapausing and in non-diapausing pupae, and only diapausing pupae had an increased SCP compared to controls. The SCPs of diapausing pupae reared on Bt cotton were significantly higher than those reared on non-Bt cotton. The trehalose levels of diapausing pupae reared on Bt cotton were significantly lower than those of larvae reared on non-Bt cotton. Thus, these results suggest that a Bt cotton diet weakens the preparedness of cotton bollworm for overwintering and reduces survival of the overwintering generation, which will in turn reduce the density of the first generation in the following year. Effects of transgenic Bt cotton on the overwintering generation of cotton bollworm appear to have significantly contributed to the suppression of cotton bollworm observed throughout northern China in the past decade.     

Quantification of diapausing fourth generation and suicidal fifth generation cotton bollworm, Helicoverpa armigera, in cotton and corn in northern China

Cotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), is a major pest of cotton and corn crops in northern China. A phenological differentiation between fourth generation cotton bollworms from cotton and those from corn fields was observed in northern China during 1999–2000. The proportion of pupation in late fall was marginally higher in cotton fields compared to that in corn fields; however, the proportions of fall emergence of moths from cotton fields were significantly higher than those from corn fields. The proportion of spring emergence of moths was also significantly higher for larvae collected from cotton (28.0%) than from corn (14.5%). The overwintering duration of females was significantly shorter than that of males in both crops. Moreover, the overwintering duration of bollworm populations from cotton was significantly longer than that from corn. The early spring population of H. armigera came from both cotton and corn fields, but the spring emergence of moths from larvae collected from cotton took about 5 days longer to reach 100% emergence compared to that from corn.     

取食Bt棉与玉米的越冬代棉铃虫抗寒性特征比较

【目的】针对由Bt棉花和玉米构成的华北农田景观, 探讨不同寄主作物对棉铃虫 Helicoverpa armigera 越冬抗寒的影响。【方法】2013年在河北廊坊科研中试基地的作物田中将棉铃虫幼虫接到Bt棉和玉米上, 比较取食不同作物后棉铃虫的化蛹率、存活率和越冬蛹羽化率;在室内控制条件下分别用棉蕾和鲜玉米粒饲喂棉铃虫幼虫。 测定滞育蛹和非滞育蛹的鲜重、干重、以及脂肪、糖原和低分子物质含量等指标, 比较取食不同作物后棉铃虫的抗寒能力。【结果】取食玉米的棉铃虫滞育蛹干重（117.5 mg）、脂肪含量（457.2 μg/mg DW）以及海藻糖浓度（86.45 μg/g）均显著高于取食Bt棉的棉铃虫滞育蛹干重（56.6 mg）、脂肪含量（239.6 μg/mg DW）以及海藻糖浓度（13.87 μg/g）;取食玉米的棉铃虫冰点(-10.2℃)显著低于取食Bt棉的棉铃虫冰点(-6.5℃)。【结论】结果表明取食玉米更加有利于棉铃虫越冬。 据历史数据, 近年来玉米种植面积不断增加, 这将提高棉铃虫成功越冬比率, 对棉铃虫种群扩张起到促进作用, 因此注重玉米上棉铃虫的防治尤为重要。     

寄主植物对棉铃虫越冬蛹抗寒能力的影响

通过对滞育蛹过冷却点的测定 ,初步明确寄主对棉铃虫Helicoverpaarmigera的越冬抗寒性有影响 ,幼虫取食棉花时产生的滞育蛹的过冷却点低于取食玉米的滞育蛹的过冷却点 ,即前者的抗寒能力高于后者 ;但用Bt棉喂养后的棉铃虫滞育蛹抗寒能力下降     

转Bt基因玉米对甜菜夜蛾幼虫存活和发育的影响

在室内测定了2种转Cry1Ab基因的Bt玉米MON810和Bt11不同组织对甜菜夜蛾 Spodoptera exigua （Hübner）初孵幼虫以及心叶对4龄幼虫存活和发育的影响,在田间比较了甜菜夜蛾幼虫取食Bt 和非Bt玉米雌穗的存活和为害情况。结果表明,转Cry1Ab基因的Bt玉米的不同组织对甜菜夜蛾初孵幼虫都具有明显的杀虫活性,取食Bt玉米心叶、苞叶、籽粒时甜菜夜蛾均在幼虫期死亡; 取食MON810和Bt11雄穗的初孵幼虫化蛹率分别为5.2%和2.1%,羽化率为2.1%和1.0%;取食MON810和Bt11花丝的初孵幼虫化蛹率分别为1.0%和2.1%,但不能羽化。4龄幼虫取食MON810玉米心叶的化蛹率与对照差异不显著,而取食Bt11的化蛹率与对照差异显著; 取食两种Bt玉米心叶的４龄幼虫化蛹后的雌、雄蛹重和羽化率与对照组差异显著,但蛹期和平均单雌产卵量差异不显著,虽然对照组羽化的成虫平均产卵量高于Bt玉米组。田间接种初孵幼虫10 天后的调查结果表明,在MON810和Bt11玉米花丝上幼虫存活率分别为1.3%和0.3%, 而对照组分别为12.9%和16.2%;MON810和Bt11玉米雌穗被害率分别为18.3%和5.0%,而对照组分别为93.3%和95.0%,均显著低于对照组。     

敲减神经肽F基因(npf)对亚洲玉米螟取食、生长发育和繁殖的影响

【目的】神经肽F(neuropeptide F, NPF)是无脊椎动物特有的一类神经肽,因其C末端是苯丙氨酸(F)而命名,参与昆虫的取食、生物节律、学习记忆等多种生理功能的调控。本研究旨在明确NPF对亚洲玉米螟Ostrinia furnacalis生长发育的影响,为害虫防治提供重要依据。【方法】采用一种基于工程菌高效合成靶向昆虫基因的dsRNA的方法经济有效地敲降npf,用低浓度(0.01%)和高浓度(0.02%)dsNPF和dsGFP(对照)分别饲喂亚洲玉米螟1龄初、3龄初和5龄初幼虫直至化蛹,检测5龄幼虫平均取食量、体重、体长、存活率和化蛹率,蛹羽化率和成虫产卵量,以及幼虫各龄期、蛹发育历期和成虫寿命。【结果】从亚洲玉米螟1, 3和5龄初幼虫开始饲喂0.01%和0.02% dsNPF时,与饲喂相应浓度dsGFP的对照相比,除个别点外,5龄幼虫的取食量、体重、体长、存活率和化蛹率,蛹羽化率和成虫单雌产卵量均显著降低,幼虫各龄期、蛹发育历期均显著延长,成虫寿命显著缩短。且dsNPF处理幼虫的龄期越早对发育的影响越大。其中0.01% dsNPF处理的1龄幼虫和0.02% dsNPF处理的3龄幼虫有90%的个体在蛹期死亡,而0.02%dsNPF处理的1龄幼虫有90%的个体在幼虫期死亡。【结论】结果提示NPF对亚洲玉米螟的发育和取食具有调控作用,这为探索新型绿色的害虫防治提供了依据。     

转Bt基因棉花对棉铃虫不同龄期幼虫的杀虫活性和抑制生长作用

以我国培育的转Bt基因棉花(简称Bt棉)为材料,系统测定了Bt棉叶片对棉铃虫 Helicoverpa armigera(Hubner)不同龄期幼虫的杀虫活性和抑制生长的作用。结果表明,Bt棉的杀虫活性随着龄期的增大而趋于降低,其中处理3d只对1龄幼虫有较高效果;从1～4龄开始连续取食Bt棉后均不能化蛹,5龄幼虫则能正常化蛹。3龄幼虫取食Bt棉叶3d后的体重与初始体重之比为0.94,而取食常规棉叶的相应比值为5.48,对幼虫生长的抑制作用明显。在28℃条件下用Bt棉饲养棉铃虫1～3龄幼虫3d,对幼虫的致死率显著高于25℃处理,对3龄幼虫抑制生长的作用也显著提高。研究结果可为确定棉铃虫对Bt棉的抗性监测与治理技术以及Bt棉的田间应用技术提供依据。     

Effects of a juvenoid, DPE-28, on biology and behaviour of Culex quinquefasciatus, the human filariasis vector

Studies on the effect of a juvenoid, DPE-28 (2,4-dinitrophenyl-2',6'-di-tertiarybutyl phenyl ether) on biology and behaviour of Cx. quinquefasciatus showed that the developmental duration, sex ratio, mating success and blood feeding were considerably affected by the exposure of larvae and pupae to the compound. Exposure of fourth instar larvae to 0.007 (EI90) and 0.0019 (EI50) ppm of DPE-28 prolonged the duration of pupation by 58.6 and 52.4 hr and delayed the adult emergence by 35.4 and 17.7 hr in males and 36.8 and 21.1 hr in females respectively. Exposure of freshly ecdysed pupae to 10 and 5 ppm delayed the adult emergence with respect to the control by 54.3 and 32.4 hr in males and 55.2 and 33.2 hr in females respectively. The sex ratio of the adults emerged from treated larvae and pupae was also affected. The female mosquitoes that survived from the exposed fourth instar larvae and pupae exhibited a low blood engorgement ratio. This depression in blood feeding was more pronounced in adults emerged from treated pupae than that of treated fourth instar larvae. A significant proportion of adults emerged from treated larvae and pupae were able to feed only partially. Mating success of the treated populations declined considerably when crosses were made between the males and females emerged from treated fourth instar larvae and pupae. The adults emerged from treated larvae and pupae showed a significant reduction in the oviposition.     

A NEW AND PRACTICAL ARTIFICIAL DIET FOR THE COTTON BOLL-WORM*

Abstract A new and practical artificial diet for the cotton bollworm, Helicoverpa armigera (Hübner), containing canned tomato paste has been developed. The developmental duration of larvae fed on the diet was greatly shortened because most of them only went through 5 stadia before pupation. To add certain amount of mung bean flour to partly substitute for wheat germ in the diet was beneficial to the adult reproduction. During rearing period of 12 successive generations, 87. 5%-98. 7% of the larvae survived and only less than 5 % of the pupae failed to emerge. The number of egg laid by the adults of the 11th generation averaged about 1 000/female, with a hatching rate of 86. 5%. These results suggested that the vitality of the cotton bollworm did not decline obviously after reared with the diet for two years.