东亚小花蝽(Orius sauteri)成虫对入侵害虫西花蓟马(Frankliniella occidentalis)成虫的捕食作用

为探明东亚小花蝽对西花蓟马的控制效能,开展了东亚小花蝽成虫对西花蓟马成虫的捕食功能反应与寻找效应研究。试验结果表明,在供试温度下,其捕食功能反应符合HollingⅡ型方程。在相同温度下,东亚小花蝽成虫的捕食量随着猎物密度的增加而增大,搜寻效应随着猎物密度的增加而降低。在18～26℃,随着温度的升高,东亚小花蝽成虫对西花蓟马成虫的捕食量增加,而在26～34℃则有相反的趋势。在相同猎物密度条件下,随着东亚小花蝽成虫密度的增大,其平均捕食量逐渐减少,捕食作用率E也相应地降低,捕食作用率E与东亚小花蝽成虫密度P的关系为E=0.5224P-0.7148,分摊竞争强度I与东亚小花蝽成虫密度P的关系为I=0.9689logP+0.0763。

西花蓟马(Frankliniella occidentalis)rDNA ITS2和COⅠ基因5’末端序列的克隆与比较分析

利用PCR技术克隆西花蓟马(Frankliniella occidentalis)的rDNAITS2和COⅠ基因5末端的部分序列,结合GenBank中相应序列对两者的突变类型、核苷酸多态性、单倍型多态性、种内平均遗传距离以及系统进化等进行比较分析.结果表明,COⅠ基因较rDNA ITS2更适合于F.occidentalis的种内遗传分析;F.occidentalis可能是由两个(或多个)株系或隐存种组成的复合体;入侵我国的F.occidentalis以温室系(greenhouse strain)为主体,也存在一定数量的羽扇豆系(lupin strain).据此,推测F.occidentalis最先是被传播至云南,再从云南扩散至北京、哈尔滨等地.本研究结果对了解我国F.occidentalis的遗传多样性、株系组成以及入侵机制具有一定意义.

温度对西花蓟马(Frankliniella occidentalis)生长发育和存活率的影响

在15、20、25℃和30℃，RH75％的条件下，分析了温度与西花蓟马发育速率的关系，并测定了西花蓟马的发育起点温度、有效积温和存活率。结果表明：在15～30℃范围内，西花蓟马各虫期的发育速率随温度的升高而加快；用直接最优法对发育起点温度和有效积温进行估算，求得西花蓟马的卵、若虫、预蛹和伪蛹及世代发育起点温度分别为5．70、7．04、4．49、6．84℃和6．23℃；世代的有效积温为219．73d·℃。西花蓟马的世代存活率在25℃时最高，为40．12％；30℃时西花蓟马的存活率最低，为17．80％。

The mRNA Expression Profiles of Five Heat Shock Protein Genes from Frankliniella occidentalis at Different Stages and Their Responses to Temperatures and Insecticides

The westem flower thrips, Frankliniella occidental＆ （Pergande） is a highly invasive pest that is able to exploit many crops across a wide range of environmental conditions. Five full-length cDNAs of heat shock protein （HSP） genes （Fo-HSP90, Fo-HSP70, Fo-HSP60, Fo-HSP40 and Fo-HSP28.9） were cloned from F. occidentalis, and their expression profiles were investigated under conditions of thermal stress and insecticide exposure, and at different stages during development, using real-time quantitative PCR. All five gene sequences showed high similarity to homologs in other species, indicating the conserved fimction of this gene family. HSP60 represents an informative phylogenetic marker at the ordinal taxonomic level within Insecta, but HSP90, which has two homologous copies in Hymenoptera, was not informative. The expression of Fo-HSPs under thermal stress suggests that Fo-HSP90, Fo-HSP70, and Fo-HSP28.9 are inducible by both cold and heat stress, Fo-HSP40 is only heat-inducible, and Fo-HSP60 is thermally insensitive. There were two patterns of cold induction of Fo-HSPs： one is from 0 to 4℃ and the other is around -8℃. All five Fo-HSPs genes were induced by exposure to sublethal concentrations of the insecticide avermectin. The expression of the five Fo-HSPs during different developmental stages suggests that they all play a role in development of F. occidentalis.

Field resistance to spinosad in western flower thrips Frankliniella occidentalis(Thysanoptera:Thripidae)

The western flower thrips, Frankliniella occidentalis, is one of the most destructive sucking pests of vegetables, fruits and ornamental crops in China. Spinosad is one of the most commonly used insecticides to manage thrips. To assess the incidence of spinosad resistance in F. occidentalis field populations in eastern China, survival rates for 24 different populations were compared with those of a susceptible laboratory strain. All populations showed significantly higher resistance to spinosad compared with the control as determined by comparing median lethal concentrations. Two populations from Shouguang and Liaocheng in Shandong Province were classified as having moderate and high levels of resistance to spinosad with a mean resistance ratio of 17.0 and 89.2, respectively. Our research indicates a widespread reduction in spinosad efficacy for controlling F. occidentalis field populations, and that resistance management strategies should be implemented as soon as practicable, to reduce the potential of progressive resistance development and loss of efficacy.

Characterization of two novel heat shock protein 70s and their transcriptional expression patterns in response to thermal stress in adult of Frankliniella occidentalis (Thysanoptera:Thripidae)

Heat shock protein 70（HSP70） is one of the most important members in the heat shock protein family, and plays important roles in the thermotolerance of insect. To explore the molecular mechanism of thermotolerance of Frankliniella occidentalis adults, the difference in the expression of HSP70s in F. occidentalis male or female adults under the thermal stress was studied under the laboratory conditions. Two full length c DNAs of HSP70s gene（Fohsc704 and Fohsc705） were cloned from F. occidentalis by using RT-PCR and RACE. The genomic sequence was demonstrated by genomic validation, and the position and size of the intron were analyzed by sequence analysis of c DNA. Real-time PCR was used to analyze the HSP70 expression patterns. The c DNA of Fohsc704 and Fohsc705 possessed 2 073 and 1 476 bp which encoded 690 and 491 amino acids（aa） with a calculated molecular weight of 75 and 54 k Da, respectively. Four introns in Fohsc704 and six introns in Fohsc705 protein were found. However, the HSP70 protein sequences in our study were ended with EKKN and GIFL, which were different from the reported Fo HSP70s. Various expression patterns of Fohsc704 and Fohsc705 were found in both genders of F. occidentalis under thermal stress. The expression of Fohsc704 and Fohsc705 reached to the highest level at –12 and –8°C in male adults, respectively, and Fohsc705 expressed the highest level at 33°C in female adults. In conclusion, HSP70s of F. occidentalis in our study are novel heat shock proteins. There were difference in expression patterns of the two hsc70s in genders of F. occidentalis, and the two HSP70s play important roles in the thermotolerance of F. occidentalis.

Systematic Analysis of Gene Expression in Western Flower Thrip( Frankliniella occidentalis Pergande ) before and after Infection with Impatiens Necrotic Spot Virus(INSV)

Impatiens necrotic spot virus( INSV) is an important plant virus identified in recent years. Western flower thrip( Frankliniella occidentalis) has been confirmed to be the most efficient vector for INSV. In the present study,Illumina's second-generation sequencing technique was used to determine the variation in gene expression at the transcriptome level in western flower thrip before and after infection with INSV. By aligning 168 188 unigenes of western flower thrip to the NCBI protein database,47 558 unigenes were annotated,accounting for 28. 27% of the total. Species classification revealed that 58. 7% of the annotated unigenes of western flower thrip did not match any other species,and 15. 4% of had a match in Zootermopsis navadensis,12. 4% in Mus musculus,7. 3% in Mustela putorius,3. 4% in Theileria parva,and 2. 7% in Tribolium castaneum. By analyzing DEGs between INSV-free and INSV-carrying western flower thrips,we found that 11 genes were upregulated,and 9 genes were downregulated in western flower thrip after INSV infection. In addition,cell cycle and ubiquitin-proteasome pathway in western flower thrip were significantly infected by INSV infection.

Effects of Nicotine, a Plant Secondary Metabolite, on Protective Enzyme and Detoxification Enzyme of Frankliniella occidentalis

[Objective] The paper was to explore the effects of plant secondary metabolite on protective enzymes and detoxification enzymes of quarantine pest Frankliniella occidentalis. [Method] F. occidentalis were continuously exposed to artificial diets containing nicotine from the second to fifth instars for five generations, and the effects of nicotine on protective enzymes and detoxification enzymes of larvae were determined. [Result]The activities of carboxylate esterase(CarE) and glutathione-S-transferase(GST) in midgut of the fifth instar larvae were significantly increased, and reached the maximum at the third generation(1.86 times and 1.59 times, respectively). Nicotine inhibited the activities of superoxide dismutase(SOD) and catalase(CAT). With the increase of feeding generations, the inhibitory effect of nicotine weakened. Nicotine significantly increased the activities of peroxidase(POD). [Conclusion] F. occidentalis will gradually adapt to the harm of plant toxins by starting its own detoxification enzyme system and regulating protective enzyme system after feeding on plant secondary substance nicotine.

Obstructor,a Frankliniella occidentalis protein,promotes transmission of tomato spotted wilt orthotospovirus

Tomato spotted wilt orthotospovirus(TSWV)causes substantial economic losses to vegetables and other crops.TSWV is mainly transmitted by thrips in a persistent and proliferative manner,and its most efficient vector is the western flower thrips,Frankliniella occidentalis(Pergande).In moving from the thrips midgut to the salivary glands in preparation for transmission,the virions must overcome multiple barriers.Although several proteins that interact with TSWV in thrips have been characterized,we hypothesized that additional thrips proteins interact with TSWV and facilitate its transmission.In the current study,67 F occidentalis proteins that interact with GN(a structural glycoprotein)were identified using a split-ubiquitin membrane-based yeast 2-hybrid(MbY2H)system.Three proteins,apolipoprotein-D(ApoD),orai-2-like(Orai),and obstructor-E-like isoform X2(Obst),were selected for further study based on their high abundance and interaction strength;their interactions with Gn were confirmed by MbY2H,yeastβ-galactosidase and luciferase complementation assays.The relative expressions of ApoD and Orai were significantly down-regulated but that of Obst was significantly up-regulated in viruliferous thrips.When interfering with Obst in larval stage,the TSWV acquisition rate in 3 independent experiments was significantly decreased by 26%,40%,and 35%,respectively.In addition,when Obst was silenced in adults,the virus titer was significantly decreased,and the TSWV transmission rate decreased from 66.7%to 31.9%using the leaf disk method and from 86.67%to 43.33%using the living plant method.However,the TSWV acquisition and transmission rates were not affected by interference with the ApoD or Orai gene.The results indicate that Obst may play an important role in TSWV acquisition and transmission in Frankliniella occidentalis.

The diurnal flight activity and influential factors of Frankliniella occidentalis in the greenhouse

The daily flight activity of westem flower thrips, Frankliniella occidentalis （Pergande） （Thysanoptera： Thripidae） was examined using color, yellow-light and chemical attractant traps in a cucumber greenhouse and under controlled laboratory conditions. In the greenhouse, flying thrips were most abundant between hours 08：00-10：00, declined at mid-day, and then slightly increased during hours 14：00-16：00; however they decreased to a very low level at 18：00. The use of light traps showed no thrip flight activity during the night. The total number of thrips that flew onto cards on rainy or cloudy days was higher than that on sunny days. We reconfirmed that traps treated with attractant attracted 4.0-9.4 times more thrip than the untreated traps. Under laboratory controlled conditions, thrip flight activity was highest under light intensity between 4 000 and 6 000 lux, air temperature of 28℃, and RH of 70%. In addition, starved thrips flew more readily than non-starved thrips.

不同光谱对东亚小花蝽捕食西花蓟马的影响

设施补光可能会影响天敌昆虫的应用效率,为探索提升天敌应用效果的补光光谱,促进补光与天敌释放技术的有机结合,本研究在相同光强和光周期的条件下,比较了红(R)、蓝(B)、红蓝组合(RB)和白(W,对照)光处理下东亚小花蝽对西花蓟马捕食能力的差异。结果表明,相比于W光,B光显著降低东亚小花蝽雌成虫的存活率,R和RB光未影响其雌成虫的存活。R和RB光显著增加东亚小花蝽在高密度猎物下对西花蓟马的捕食量。不同光谱处理下东亚小花蝽雌成虫对西花蓟马雌成虫的捕食能力均符合HollingⅡ型功能反应模型,且搜寻效应随猎物密度增加逐渐降低。RB光处理下,东亚小花蝽捕食西花蓟马的效果最好,理论日最大捕食量最高,为43.10头/d,单头猎物处理时间最短,为0.0232d;B光的理论日最大捕食量也较高,为42.90头/d,单头猎物处理时间为0.0233d;R光下东亚小花蝽捕食西花蓟马的瞬时攻击率最高为1.0837。东亚小花蝽对西花蓟马的搜寻效率最高的是RB光处理,其次是R或B光,最低的是W光。以上结果表明,相比于W光,R、B和RB光均增加东亚小花蝽对西花蓟马的捕食能力和搜寻效率,但B光会降低东亚小花蝽的存活率。因此,与设施补充R和RB光相结合,可潜在提升东亚小花蝽对西花蓟马的捕食效果。本文基于捕食功能差异评价了三种常用补光光谱对东亚小花蝽捕食西花蓟马的影响,为设施补光兼顾天敌应用提供了基础数据。

烟台地区花生田害虫发生动态分析

为进一步了解山东烟台地区花生田主要害虫发生种类和发生动态,2017—2020年,利用色板诱集法对山东烟台地区花生田间害虫进行系统监测。结果表明,烟台地区花生田地上害虫优势种群主要有西花蓟马、花生蚜虫、叶蝉、潜蝇、虻科。西花蓟马多暴发于7、8月,虫口数量显著高于其他月份。西花蓟马虫口密度与平均气温、平均地温、日照时间呈正相关,其中与平均气温、平均地温呈显著相关;与平均相对湿度、降雨、风速呈负相关但不显著。

西花蓟马抗药性分子机制研究进展

西花蓟马(Frankliniella occidentalis)是世界范围内对蔬菜、水果和观赏作物最具破坏性的害虫之一,其通过直接取食植物并传播多种病毒对植物造成危害。由于杀虫剂的大量使用导致西花蓟马对多种杀虫剂产生了抗药性。因此,深入研究其抗药性分子机制,可为西花蓟马的综合治理和绿色防控提供重要的理论依据。本文综述了西花蓟马对多种杀虫剂的抗性分子机制研究进展,主要包括与抗药性有关的解毒酶和转运蛋白基因的功能,以及相关基因的调控路径等方面,对目前存在的问题提出了可行性的建议并展望了未来防治西花蓟马的发展方向。

五种药用植物对西花蓟马成虫选择行为的影响

【目的】验证药用植物及其挥发物成分对西花蓟马Frankliniella occidentalis成虫选择行为干预的可行性,为农业害虫防治提供解决方案。【方法】利用Y型嗅觉仪测定西花蓟马成虫对3种蔬菜植物(番茄Solanum lycopersicum、黄瓜Cucumis sativus和辣椒Capsicum annuum)和5种药用植物(薄荷Mentha piperita、紫苏Perilla frutescens、荆芥Nepeta cataria、益母草Leonurus cardiaca和藿香Ageratum conyzoides)的选择率;通过气相色谱-质谱联用(gas chromatography-mass spectrometry, GC-MS)鉴定5种药用植物叶片中共有挥发物成分;使用Y型嗅觉仪检测西花蓟马成虫对0.01, 0.1, 1, 10和100μL/mL β-石竹烯的选择率。【结果】在选择行为试验中,西花蓟马成虫对5种药用植物均表现出忌避行为,其中对紫苏和藿香的忌避行为较为显著(选择率分别为24.45%和24.53%)。GC-MS鉴定出5种药用植物叶片中挥发物共有成分为β-石竹烯和2, 2′-亚甲基双(6-叔丁基对甲酚)。西花蓟马成虫对0.01μL/mL β-石竹烯无明显行为反应,对0.1~100μL/mL β-石竹烯表现出明显的忌避行为,并且高浓度(10~100μL/mL)β-石竹烯对西花蓟马成虫的驱避率可达到约85%。【结论】测试的5种药用植物对西花蓟马成虫表现出较为显著的驱避效果,该结果为了解西花蓟马对非寄主植物的选择性提供理论依据;β-石竹烯是5种药用植物叶片中的共有挥发物成分,可作为驱避剂或植物源农药用于西花蓟马的农业治理。

5种杀虫剂对西花蓟马的室内毒力及其对巴氏新小绥螨的安全性评价

【目的】筛选对西花蓟马(Frankliniella occidentalis)防控效果显著且对巴氏新小绥螨(Neoseiulus barkeri)安全的杀虫剂,为联合使用杀虫剂和捕食螨防控西花蓟马提供参考。【方法】分别使用60 g/L乙基多杀菌素悬浮剂、苦参碱、25%噻虫嗪水分散粒剂、5%阿维菌素和70%吡虫啉共5种常用杀虫剂浸渍过的菜豆豆荚饲喂西花蓟马,48 h后测定其对西花蓟马成虫的防控效果;将巴氏新小绥螨放入喷洒过药剂的捕食螨饲养麦麸中,48 h后测定其对巴氏新小绥螨的安全性。【结果】这5种杀虫剂对西花蓟马的虫口减退率分别为97.78%、95.00%、92.22%、88.89%和59.56%,防控效果依次为97.52%、94.43%、91.34%、87.43%和55.42%,乙基多杀菌素、苦参碱和噻虫嗪对西花蓟马的防控效果较好。与清水对照组相比,苦参碱、噻虫嗪、乙基多杀菌素、吡虫啉和阿维菌素对巴氏新小绥螨的虫口减退率分别为11.37%、9.71%、9.15%、8.04%和4.70%,其中,阿维菌素对巴氏新小绥螨虫口数量的影响最小,安全性最高。【结论】单独使用时,乙基多杀菌素、苦参碱和噻虫嗪可作为生产中防控西花蓟马的推荐药剂;与天敌组合使用时,阿维菌素与巴氏新小绥螨联合使用能够充分发挥杀虫剂的药效和捕食螨的捕食作用,乙基多杀菌素和噻虫嗪则应在捕食螨充分定殖后使用。

77种植物提取物杀虫活性初步研究

为评价39科77种植物的杀虫活性,本研究采用叶碟喷雾法、浸渍法和喷雾法,分别测定了植物乙醇提取物对二斑叶螨、西花蓟马和麦长管蚜的杀虫活性,进一步测定了杀虫活性较高的植物对二斑叶螨、西花蓟马和麦长管蚜的室内毒力。结果表明:在1 g/m L的供试剂量下,颠茄、蟛蜞菊、咽喉草、菝葜、沙棘、石竹、凌霄花、山佩兰8种植物对二斑叶螨的72 h校正死亡率较高,均在70%以上;LC_(50)分别为254、297、413、424、428、553、663、725 mg/m L;颠茄、蟛蜞菊对西花蓟马的72 h校正死亡率均在80%以上,其LC_(50)分别是272、306 mg/m L;菝葜、咽喉草、沙棘、羊角蒿、凌霄花和山佩兰对西花蓟马72 h的校正死亡率在70%~80%,其LC_(50)分别为446、485、523、563、710、712 mg/m L;虎杖、颠茄、牛叠肚、地肤子、狼毒5种植物对麦长管蚜72 h的校正死亡率在70%以上,其LC_(50)分别为281、336、540、657、730 mg/m L。因此,颠茄、虎杖、蟛蜞菊、菝葜等植物对不同供试昆虫的校正死亡率均较高,表现出良好的杀虫活性,值得进一步研究。

3种瓢虫对西花蓟马和烟粉虱的控制能力研究

本研究旨在探讨多异瓢虫、七星瓢虫和十斑大瓢虫这3种天敌昆虫对西花蓟马和烟粉虱的生物防治潜能。在室内条件下,用田间采集的西花蓟马和烟粉虱若虫对3种瓢虫进行不同益害比的饲喂试验,试验过程中记录各处理西花蓟马虫口密度、烟粉虱若虫有咬痕个数及羽化的成虫比例。结果表明,西花蓟马饲喂处理3 d后,3种瓢虫成虫和幼虫对西花蓟马的控制能力由强到弱为:多异瓢虫成虫>七星瓢虫3龄幼虫>七星瓢虫成虫>十斑大瓢虫3龄幼虫>多异瓢虫3龄幼虫>十斑大瓢虫成虫,其中多异瓢虫成虫对西花蓟马的防治效果最高,达到48.35%。烟粉虱若虫饲喂处理3 d后,十斑大瓢虫幼虫处理组中烟粉虱低龄若虫有咬痕的个数占比为2.61%,显著高于对照组,其余处理间没有显著性差异;各处理组烟粉虱成虫羽化率之间没有显著性差异。研究表明,多异瓢虫成虫对西花蓟马的防治效果较高,十斑大瓢虫幼虫对烟粉虱低龄若虫具有一定取食趋性,但3种瓢虫对烟粉虱高龄若虫均没有取食趋性。

西花蓟马(Frankliniella occidental)在白三叶草上的空间分布

利用5种聚集度指标和线性回归方程对西花蓟马在白三叶草上的空间分布型进行研究。结果表明:西花蓟马在白三叶草上的空间分布型为聚集分布,其分布的基本成分是个体群,个体间相互吸引,这种聚集主要由环境引起。运用Iwao的m*-m直线回归方程建立了理论抽样数模型,田间理论抽样数可用N=1/D2(1.3533/m+1.964)进行估计。

基于刺吸电位技术的西花蓟马取食行为研究进展

西花蓟马是一种世界性的重要农业害虫,对蔬菜和花卉等园艺作物的生产构成了巨大威胁,该害虫造成的危害与其取食行为密切相关。刺吸电位技术(EPG)是研究刺吸式和锉吸式口器昆虫取食行为的重要工具,在揭示害虫的取食机制、寄主植物的防御、害虫与寄主植物互作等方面发挥了重要作用。本文综述了西花蓟马取食行为波形的划分、寄主种类、病毒和杀虫剂对西花蓟马取食行为的影响,为西花蓟马的防控奠定了基础。

西花蓟马对蔬菜不同器官的选择性研究

为研究西花蓟马对不同寄主蔬菜及其不同器官的选择性,进一步明确西花蓟马与寄主之间的关系,阐明该虫对寄主植物的选择机制,研发有效的引诱剂或驱避剂,本文对不同寄主蔬菜及其不同器官上西花蓟马的种群数量进行分析。结果表明,西花蓟马喜好在寄主蔬菜的花器官上,且中部和上部居多,其次是叶,茎、果实。在不同寄主蔬菜的花器官上,西花蓟马数量由多到少为茄子、西葫芦、黄瓜、辣椒、番茄、甜瓜。