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1.
【目的】研究马铃薯叶片内生细菌对马铃薯块茎蛾幼虫的杀虫活性,为马铃薯块茎蛾生物防治提供理论依据。【方法】以云南省2种马铃薯主栽品种丽薯6号和会-2叶片为材料,采用LB固体培养基分离培养马铃薯叶片内生细菌,根据内生细菌的形态特征和16S rDNA序列进行种类鉴定;通过浸叶饲喂法测定内生细菌的发酵液、发酵上清液和菌悬液对马铃薯块茎蛾3龄幼虫的毒力。【结果】分别从丽薯6号和会-2叶片中分离获得对马铃薯块茎蛾3龄幼虫具有杀虫活性的苏云金芽孢杆菌(Bacillus thuringiensis)QL1和带化红球菌(Rhodococcus fascians)YH2。分别用浓度为1.5×109CFU/mL的菌株QL1和YH2发酵液饲喂马铃薯块茎蛾3龄幼虫后第7 d时,其幼虫累积死亡率分别为81.67%和65.00%,LT50分别为3.03和5.58 d;菌株QL1发酵液处理后第3、5和7 d马铃薯块茎蛾3龄幼虫的LC50分别为7.99×108、3.21×106和2.73×103CFU/mL;菌株YH2菌体无明显致死效应。在1.5×109CFU/mL浓度下,菌株QL1和YH2发酵液对马铃薯块茎蛾3龄幼虫的杀虫活性高于发酵上清液和菌悬液。菌株QL1和YH2的发酵液、发酵上清液、菌悬液处理后马铃薯块茎蛾3龄幼虫的累积死亡率均随着处理时间变长而逐渐升高。【结论】马铃薯叶片内生细菌苏云金芽孢杆菌菌株QL1和带化红球菌菌株YH2的发酵液、发酵上清液、菌悬液对马铃薯块茎蛾3龄幼虫均具有杀虫活性,可作为马铃薯块茎蛾生防制剂开发的潜力菌株。 相似文献
2.
Two-way predation between immature stages of the hoverfly Eupeodes corollae and the invasive fall armyworm(Spodoptera frugiperda J. E. Smith) 
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下载免费PDF全文 Hui LI Shan-shan JIANG Hao-wen ZHANG Ting GENG Kris A.G. WYCKHUYS Kong-ming WU 《农业科学学报》2021,20(3):829-839
Since its 2018 invasion of eastern Asia, the fall armyworm Spodoptera frugiperda(Lepidoptera: Noctuidae) has become a key pest in local maize production. Though pesticides have been widely used to mitigate the initial S. frugiperda attack, biological control is receiving ample attention as a desirable, environmentally-sound alternative to chemical control. Hoverflies(Diptera: Syrphidae) are abundant natural enemies in Chinese maize fields and have been observed to consume S. frugiperda larvae. In this study, we use laboratory assays to study the two-way interaction between immature stages of S. frugiperda and the endemic syrphid Eupeodes corollae. To mimic natural conditions, assays were performed in the presence of fresh maize leaves. Those 2 nd or 3 rd instar larvae of E. corollae preyed on 1 st and 2 nd instar S. frugiperda larvae with a Holling type III response, consuming a respective theoretical maximum of 43.48 and 83.33 larvae over a 24-h period. Conversely, once S. frugiperda larvae reached 3 rd instar, they exhibited aggressive behavior and equally preyed on syrphid larvae with a Holling type III response. Those 5 th and 6 th instar larvae of S. frugiperda consumed a respective 16.39–19.23, 6.02–19.61 and 6.76–8.26 of 1 st, 2 nd and 3 rd instar E. corollae larvae per day. Though our results await field-level validation, S. frugiperda agonistic(i.e., defensive) and consumptive behavior towards resident natural enemies such as E. corollae possibly degrades biotic resistance and raises its invasion potential. Our findings shine new light on the interaction between lepidopteran herbivores and their natural enemies, and can help advance the development of conservation biological control and other integrated pest management(IPM) strategies against S. frugiperda in China and abroad. 相似文献
3.
Effect of three insect-resistant maizes expressing Cry1Ie,Cry1Ab/Cry2Aj and Cry1Ab on the growth and development of armyworm Mythimna separata(Walker) 下载免费PDF全文
下载免费PDF全文 Three transgenic maize events(IE09 S034, Shuangkang 12–5 and C0030.3.5) produced Cry1 Ie, Cry1 Ab/Cry2 Aj and G10-EPSPS, Cry1 Ab and EPSPS, respectively, all of which target the Asian corn borer. The oriental armyworm Mythimna separata(Walker) is the secondary target. In this study, the effects of the three Bt maizes on the development and survival of armyworm were studied. The results showed that IE09 S034 had insecticidal activity against 1 st instar larvae, and the survival rate of armyworm fed with Bt maize for 10 days was 46.2%, significantly lower than that of the control. The larvae at 3 rd–6 th instar were more tolerant of the Bt toxin than the early instar larvae. However, Shuangkang 12-5 had good insecticidal activity against 1 st–5 th instar larvae. The mortality was nearly 100% when the larvae were fed with Shuangkang 12-5 before 3 rd instar, and the toxin had quick-acting efficacy. This event significantly inhibited the development of armyworm; that is, the larval duration of the 3 rd and 4 th instar larvae fed with Shuangkang 12-5 was prolonged by 4.5 and 3.0 days, respectively. The pupal weight and egg number were also significantly lower than those of the control. For C0030.3.5, it could control 1 st–5 th instar larvae effectively. The mortality rates were all over 50% if 1 st–3 rd larvae were fed with this event. The pupal weight of 4 th–6 th instar larvae fed with Bt maize were only 53.9, 56.8 and 54.6%, respectively, compared to that of the control. The number of eggs laid was significantly less than the control. The results indicate that all three transgenic maize events exhibit the potential to provide effective control of early instar larvae of armyworm, which can be commercialized in future to control lepidoptera pests such as Asian corn borer and armyworm. 相似文献
4.
黑背毛瓢虫是蚜虫的重要捕食性天敌之一,对蚜虫具有明显的控制作用。研究了黑背毛瓢虫对大豆蚜虫的捕食功能反应。结果表明:黑背毛瓢虫对大豆蚜虫的日捕食量,4龄幼虫最大,3龄和2龄幼虫次之,成虫和1龄幼虫最小。捕食者对猎物的功能反应均属于Holling-Ⅱ型方程。黑背毛瓢虫成虫及1～4幼虫对大豆蚜的捕食功能反应模型依次为:Na1=1.0299Nt1/(1+0.0315 Nt1),Na2=1.0229 Nt2/(1+0.0232 Nt2),Na3=1.1366 Nt3/(1+0.0123 Nt3),Na4=1.1302 Nt4/(1+0.0100 Nt4),Na5=1.1156 Nt5/(1+0.0064 Nt5)。 相似文献
5.
菜青虫为害春甘蓝不同生育期对产量的影响及经济阈值的研究 总被引：2，自引：0，他引：2
应用均匀设计方法,测定了菜青虫连续为害春甘蓝结球始期和菜球充实期造成的产量损失,并应用生命表方法评价了春甘蓝上有青虫天敌的作用,建立了包括甘蓝生育期和菜青虫种群密度在内的产量损失模型和包含各类天敌作用的防治指标模型。结果表明,产量损失主要是由甘蓝结球始期的虫害造成,捕食性天敌对菜青虫控制作用最大,其排除作用控制指数为4．7107。根据防治指标模型,可求出甘蓝结球始期和菜球充实期以1－2龄幼虫、3－4龄幼虫、5龄幼虫为依据的防治指标,分别为每株14．13头、7．69头、3．44头（结球始期）,29．34头、12．26头和6．93头（菜球充实期）。 相似文献
6.
Susceptibility and tissue specificity of Spodoptera frugiperda to Junonia coenia densovirus 下载免费PDF全文
下载免费PDF全文 Zu-wen CHEN Yan-chao YANG Jian-feng ZHANG Ming-hui JIN Yu-tao XIAO Zhi-chao XIA Yuan-yuan LIU Sai-zhen YU Yong-bo YANG Yuan WANG Yi LI Kai-yu LIU 《农业科学学报》2021,20(3):840-849
The fall armyworm, Spodoptera frugiperda, which destroys many economic crops such as rice and maize, has recently invaded China. Insect viruses as biological control agents play important roles in killing pests. One potential viral insecticide is the environmentally highly infective and virulent densovirus. We successfully rescued Junonia coenia densovirus(JcDV) using its infectious clone in different insect cell lines and larvae of three insect species. Results showed that the lysate of cultured insect cells transfected by the JcDV infectious clone killed the 2 nd instar S. frugiperda. The LD_(50) of homogenate from JcDV-infected Spodoptera litura to the 2 nd instar S. frugiperda(1.76×10~8 viral genome copies per larva during 10 d post infection) was higher than that of the 2 nd instar S. litura(7.39×10~7 Jc DV genome copies) or Helicoverpa armigera larvae(9.71×10~7 JcDV genome copies). The LT_(50) of the S. litura homogenate(2.60×10~9 viral genome copies each larva) to the 2 nd instar S. frugiperda was 6.96 d, longer than that of the S. litura(6.18 d) or the 2 nd instar H. armigera(5.94 d). JcDV could infect the fat body of H. armigera, but not S. frugiperda or S. litura. Although JcDV can infect all three lepidopteran species, their susceptibility to the virus differs. JcDV has great potential as a biological control agent against pests such as S. frugiperda. 相似文献
7.
Opisina arenosella has been an outbreak pest of coconut trees in southern China since 2013. To develop efficient control methods for this invasive pest, adequate rearing protocols are desirable. In this study, an orthogonal array of artificial diets with 11 factors at 3 levels was deployed for both 2 nd–4 th and 5 th–6 th instar larvae of O. arenosella. Biological parameters including survival time of larvae, development time from larva to pupa, pupation rate, emergence rate, and pupal weight were monitored to reveal the most important components in the diet formulas. Biological parameters in O. arenosella were most affected by brewer's yeast, sucrose, ascorbic acid, and wheat germ. Statistical analysis indicated that different diet combinations supported optimum performance of biological parameters for 2 nd–4 th and 5 th–6 th instar larvae. The validity of the optimization predicted by the orthogonal array analysis was confirmed in a follow-up bioassay with similar optimized diets for both 2 nd–4 th and 5 th–6 th instar larvae. The optimal artificial diet has great potential for the mass rearing technique, and can provide valuable results for using parasitoids in biological control of O. arenosella. 相似文献
8.
观察了小菜蛾(Plutella xylostella)被寄生时的龄期对菜蛾绒茧蜂(Cotesia plutellae)发育历期、结茧率及羽化雌蜂寄生能力的影响.结果发现：寄生于3龄小菜蛾幼虫的菜蛾绒茧蜂其卵—幼虫期的发育较寄生于2龄或4龄个体的要快，结茧率及羽化后雌蜂寄生能力要高，但寄生不同龄期寄主个体间的成蜂羽化率没有差异，表明小菜蛾3龄幼虫较2、4龄幼虫对菜蛾绒茧蜂的适合性要高.不同龄期被寄生的小菜蛾幼虫均有部分个体在寄生蜂幼虫成熟啮出前死亡，这种死亡在2龄、3龄时被寄生的个体中主要发生在幼虫期，而4龄幼虫被寄生的个体死亡发生期则逐渐向蛹期转移，4龄第三天被寄生的小菜蛾蛹期死亡率达62.5%，表明小菜蛾4龄幼虫对菜蛾绒茧蜂的适合性随年龄增加迅速下降.文中还讨论了寄主龄期适合性与该蜂产卵选择性的关系. 相似文献
9.
斜纹夜蛾侧沟茧蜂对寄主龄期的选择 总被引：9，自引：1，他引：9
应用均匀设计研究了斜纹夜蛾侧沟茧蜂与斜纹夜蛾1龄末-2龄初幼虫、3龄幼虫和4龄幼虫共存系统中，寄生蜂对不同龄期幼虫的选择寄主作用，建立了3个龄期的3个龄期的幼虫被寄生量模型。根据模型，计算了寄生蜂对3个龄期幼虫寄生的选择系数。结果表明，斜纹夜蛾侧沟茧蜂能寄生斜纹夜蛾1-4龄幼虫，但当1龄末-2龄初幼虫、3龄幼虫和4龄幼虫同时存在时，该蜂偏爱寄生1龄末-2龄初幼虫，其次为3龄幼虫。 相似文献
10.
烟青虫生物学特性观察 总被引：4，自引：0，他引：4
1996～1997年在云南省红河烟区弥勒县的烤烟大田设置尼龙纱网养虫室,自然条件下连续饲养烟青虫Heliothis assulta(Guene),系统观察各虫态历期、幼虫龄期、取食量及体色变化,幼虫化蛹龄期及成虫羽化、产卵等.结果表明,烟青虫1年发生4～5代,各代均有5龄和6龄幼虫化蛹,5龄幼虫化蛹占60%以上;1龄幼虫历期比2龄历期长,3龄以后龄期增长,末龄(5龄或6龄)幼虫龄期最长;5龄化蛹的幼虫平均历期比6龄化蛹的短;无论5龄或6龄化蛹,3龄以后食量剧增,5～6龄的取食量为1～4龄取食量的1倍以上;幼虫体色多变,1龄幼虫均为红褐色,2～6龄体色变化无规律可循,第2代以后体色有随世代增加而加深的趋向;成虫产卵量与补充营养关系密切,补充营养充足时,每雌可产卵600～900粒,一般情况产400～500粒,未交配雌虫也会产卵,但卵不能孵化.根据观察结果提出了防治中应注意的问题. 相似文献
11.
在自然条件下，对松瘿小卷蛾幼虫的发育进度作系统调查，然后通过常规的数学分析方法，确定幼虫的龄数和龄期。测定的结果是，松瘿小卷蛾幼虫共7龄，各龄幼虫众数龄期分别为：Ⅰ龄38．25d,Ⅱ龄39．3d,Ⅲ龄32d，1d，Ⅳ龄35．24d，Ⅴ龄24．7d,Ⅵ龄238．36d（含越冬时间），Ⅶ龄29．8d。 相似文献
12.
双七瓢虫是蚜虫的重要捕食性天敌之一,对大豆蚜具有明显的控制作用。试验测定了双七瓢虫对大豆蚜的捕食功能反应,结果表明:双七瓢虫捕食大豆蚜的数量与大豆蚜密度呈负加速曲线关系,双七瓢虫4龄幼虫对大豆蚜的日捕食量最大,3龄幼虫和成虫次之2,龄和1龄幼虫最小,捕食者对猎物的功能反应均属于Holling-Ⅱ型方程。双七瓢虫成虫及1～4龄幼虫对大豆蚜的捕食功能反应模型依次为:Na1=1.1305Nt1/(1+0.0137 Nt1),Na2=0.8564 Nt2/(1+0.0491 Nt2),Na3=0.7158 Nt3/(1+0.0142 Nt3)。Na4=0.9983 Nt4/(1+0.0097 Nt4),Na5=1.1309 Nt5/(1+0.0089 Nt5)。 相似文献
13.
甜菜夜蛾不同龄期幼虫药剂敏感性及酶活性差异 总被引：8，自引：0，他引：8
采用虫体浸渍法测定辛硫磷、抑太保、高效灭百可、美满对不同龄期甜菜夜蛾(Spodoptera exigua)幼虫的毒力。结果表明2,3,4龄幼虫随龄期增加耐药性增强,2龄幼虫对药剂最为敏感,到3龄后耐药性迅速增强。随虫龄的增加,单头幼虫乙酰胆碱酯酶、磷酸酯酶、羧酸酯酶、谷胱甘肽-S-转移酶活性显著增强。 相似文献
14.
【目的】探究天敌昆虫异色瓢虫Harmonia axyridis对草地贪夜蛾Spodoptera frugiperda的捕食潜力。【方法】在室内条件下评价异色瓢虫成虫和4龄幼虫对草地贪夜蛾1～2龄幼虫的捕食能力,观察并总结异色瓢虫的捕食行为特点。【结果】通过观察,发现异色瓢虫捕食草地贪夜蛾幼虫主要经过静止、搜寻、试探、取食和爬行5种行为,其中异色瓢虫成虫捕食3龄草地贪夜蛾幼虫时出现3对足抱握猎物的现象。异色瓢虫成虫和4龄幼虫对草地贪夜蛾1～2龄幼虫的捕食功能反应符合HollingⅡ模型。异色瓢虫成虫和4龄幼虫对草地贪夜蛾1龄幼虫的日最大捕食量分别为196.08和161.29头,瞬时攻击率分别为1.390 6和1.451 4,处理时间分别为0.005 1和0.006 2 d;异色瓢虫成虫和4龄幼虫对草地贪夜蛾2龄幼虫的日最大捕食量分别为65.36和41.84头,瞬时攻击率分别为1.145 7和1.271 0,处理时间分别为0.015 3和0.023 9 d,即异色瓢虫成虫对草地贪夜蛾幼虫的捕食能力强于4龄幼虫。【结论】异色瓢虫对草地贪夜蛾有一定的潜在控害能力,可用于防控草地贪夜蛾。 相似文献
15.
为探索息半夏皮中的生物活性物质在小菜蛾防治上的应用。采用叶片浸渍法和浸虫法测定息半夏皮干粉95％乙醇提取物对3龄小菜蛾幼虫的拒食活性、触杀活性和胃毒活性。结果显示：在选择性拒食试验中,95%乙醇提取物对试虫24 h和48 h的拒食中浓度(AFC50)分别为30.89 mg/mL和38.71 mg/mL;非选择性拒食试验中,对试虫24 h和48 h的拒食中浓度(AFC50)分别为24.63 mg/mL和6.54 mg/mL;同时,息半夏皮95%乙醇提取物对小菜蛾的触杀和胃毒作用显示,100 mg/mL粗提物72 h对其校正死亡率分别为63.54%和70.2%。息半夏皮乙醇提取物对小菜蛾幼虫的拒食和胃毒作用较为突出。 相似文献
16.
[目的]了解吡咯类杀虫剂溴虫腈对家蚕不同性别的毒力差异。[方法]以家蚕卵色限性品种卵2为供试材料,采用浸叶法测定溴虫腈对家蚕雌、雄2～5龄起蚕的半致死浓度(LC50)。[结果]溴虫腈对该品种雄蚕各龄期起蚕的LC50都高于同一龄期的雌起蚕,不同龄期中溴虫腈对3龄雌起蚕和雄起蚕的毒力最大,然后依次为2、4、5龄雌起蚕和雄起蚕。[结论]家蚕起蚕雌雄性别对溴虫腈的耐受性存在明显差异,该研究结果为进一步研究家蚕对溴虫腈的耐受性机理奠定了基础,也为指导蚕桑安全生产、专养雄蚕和防治鳞翅目害虫提供了参考。 相似文献
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18.
为明确蛇莓[Duchesnea indica(Andr)Focke]中杀蚊幼活性成分,以淡色库蚊(Culex pipiens pallens)和白纹伊蚊(Aedes albopictus)3龄幼虫为试虫,采用活性跟踪法,对蛇莓乙醇提取物进行活性成分分离、鉴定和活性测定。从蛇莓乙醇提取物乙酸乙酯相中得到2个具有杀蚊幼活性的化合物,鉴定为齐墩果酸和芹菜素。浸渍法测定表明,乙酸乙酯萃取相对淡色库蚊和白纹伊蚊3龄幼虫LC50值分别为459.12和438.09mg/L,正丁醇相为471.41和430.81mg/L,显示较好的杀蚊幼活性,且乙酸乙酯相和正丁醇相差异性不显著;齐墩果酸对淡色库蚊和白纹伊蚊3龄幼虫24h处理LC50值分别为25.36和22.31mg/L,芹菜素对淡色库蚊和白纹伊蚊3龄幼虫24h处理LC50值分别为31.29和27.22mg/L。 相似文献
19.
印楝素对草地贪夜蛾的毒力测定及田间防效 总被引：2，自引：0，他引：2
【目的】评价印楝素对草地贪夜蛾Spodoptera frugiperda的毒力与防效,为草地贪夜蛾的防治提供技术参考。【方法】采用浸叶法与喷雾法测定了印楝素对草地贪夜蛾的室内毒力和田间防治效果。【结果】在室内条件下,0.3%(φ)印楝素乳油处理草地贪夜蛾7 d后,2龄和3龄幼虫的LC50值分别为0.59和0.46 mg/L;40%(w)印楝素干粉处理草地贪夜蛾7 d后,2龄和3龄幼虫的LC_(50)值分别为0.93和0.79 mg/L。0.3%印楝素乳油处理草地贪夜蛾3 d后,2龄和3龄幼虫的AFC50值分别为0.30和0.12 mg/L;40%印楝素干粉处理草地贪夜蛾3 d后,2龄和3龄幼虫的AFC50值分别为0.53和0.30 mg/L。0.3%印楝素乳油稀释500倍喷雾处理后1、3和7 d对草地贪夜蛾的防效分别达到了24.83%、50.34%和75.50%。【结论】印楝素对草地贪夜蛾具有较好的毒杀活性与拒食活性,7 d后的防治效果较好;印楝素对草地贪夜蛾的防治具有广阔的应用前景。 相似文献
20.
酚氧化酶在昆虫的免疫防御机制中起着非常重要的作用。利用在GenBank上登录的野桑蚕酚氧化酶原基因的cDNA序列,设计正反向特异引物,通过半定量RT-PCR技术检测了酚氧化酶原基因PPO1及PPO2在野桑蚕不同发育时期(蚁蚕、一龄、二龄、三龄、四龄、五龄1~6 d、预化蛹和蛹)的转录表达活性。结果表明,PPO1基因除了五龄1 d无表达及二龄表达量较低外,其他时期的表达量均较高。PPO2基因在野桑蚕的不同发育时期中均有表达,并且没有明显的差异。说明在野桑蚕的不同发育时期,PPO1基因的表达是特异性的,而PPO2基因的表达是非特异的。 相似文献