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.

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。

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 Plant Secondary Metabolite Nicotine on Growth and Development of Frankliniella occidentalis

[Objective] The paper was to explore the chemical and molecular mechanisms of Frankliniella occidentalis, an important quarantine pest, against toxic substances. [Method] F. occidentalis were evaluated after continuous exposure to artificial diets containing nicotine from the 2^（nd） and the 3^（rd）instars for five generations, to determine the larval weight, pupal weight, and larval development duration. [Result] The larval development delayed and nicotine treatment significantly inhibited the weight gain of larvae. Compared to the control, the inhibition rates of larval weight and pupal weight were declined from 45% to 20% and from 25% to 4% respectively after feeding the 2^（nd）instars with nicotine for five generations.Nicotine delayed the larval growth and prolonged the generation duration of F. occidentalis. Nicotine showed more significant inhibitory effect on the lower instar larvae. With the increasing generations of secondary culture, the inhibitory effect of nicotine on larval weight and pupal weight was weakened. The developmental period of larvae was shortened, and the generation duration of F. occidentalis was shortened. [Conclusion] Nicotine affects the growth and development of F. occidentalis. F. occidentalis will gradually increase the adaptability to nicotine toxic substances after selfregulation for a few generations, and relieve the inhibitory effect of toxic substances.

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.

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.

害虫与天敌个体数量比值对天敌竞争作用指数的影响——以茶园花蓟马及其主要天敌为例

为合理保护和利用自然天敌,明确害虫与天敌个体数量比值对天敌竞争作用指数(竞争系数和竞争强度指数)的影响。运用竞争系数分析法、灰色关联度分析法、竞争强度指数分析法和Pearson相关系数法对2020年、2021年三种茶园花蓟马与主要天敌个体数比值对主要天敌竞争作用指数的影响。三种茶园两年数据汇总分析得出,竞争系数和竞争强度指数均值与花蓟马-天敌比值的Pearson相关系数分别为-0.7858和-0.8199;2020年三种茶园数据综合分析得出,竞争系数和竞争强度指数均值与花蓟马-天敌比值的Pearson相关系数分别为-0.7391和-0.7819;2021年三种茶园竞争作用指数与比值的跟随关系不明显,主要是平阳特早茶园9种主要天敌以外的其他天敌影响了竞争作用趋势。综合多种分析结果得出,9种主要天敌的竞争作用指数与花蓟马-天敌比值呈显著负相关,其中三突花蟹蛛(-0.9936)负相关性最显著,鞍型花蟹蛛是高比值组竞争作用指数最高的天敌。研究结果为利用天敌开展花蓟马生物防治提供参考。

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.

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。

大同黄花田间杂草种类调查及杂草与蓟马的相互影响

目的 探究大同黄花田间草害和蓟马发生情况,为制定综合协同防控策略提供依据。方法 对大同黄花田间杂草种类和蓟马成虫发生情况进行调查分析,总结规律。结果 发现11科31属38种杂草,其中一年生植物7科20属23种,多年生植物6科13属16种,外来入侵物种4科5属6种。相对多度分析表明,苋科刺藜属刺藜、禾本科狗尾草属狗尾草、蒺藜科蒺藜属蒺藜为优势种;凹头苋、稷、藜、田旋花、猪毛菜、豚草、猪毛草、黄花蒿为常见杂草,其中凹头苋和豚草为外来入侵物种。比较有、无防除杂草的大同黄花地块蓟马成虫发生情况表明,杂草的生长可降低蓟马成虫的发生。结论 大同黄花田间有38种杂草,优势种3种,常见种8种。特定时期杂草的存在对蓟马成虫发生有一定的抑制作用。

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。

Tiny insects against the weather flight and foraging patterns of Frankliniella schultzei (Thripidae) not altered by onset of rainfall

To survive in nature,organisms may need to take direct action to mitigate specific dangers from their environmental surroundings.Tiny flying insects are thought to be at particular risk from rainfall that would be of negligible concern to larger animals.The study species Frankliniella schultzei is a thrips that inhabits flowers and feeds mostly on petal tissue and pollen.While found to respond in the laboratory to decreases in atmospheric pressure associated with cyclonic conditions (rather than merely heavy rainfall),their responses to conditions preceding rainfall have not been tested in the field.Initial field sampling investigated the relationship between floral development and sites at which male,female,and larval thrips were generally present on sunny days.We then designed a sampling strategy to test if these thrips can anticipate imminent rainfall or storms and so seek shelter deep within flowers,by sampling host flowers (in sections)on multiple days with different weather conditions.Sticky traps were used to intercept thrips in flight,thus providing a measure of flight behavior across different days.The initial sampling found adult thrips primarily at the petal apex of anthesis-stage flowers where pollen is distributed. We subsequently found that rainfall,atmospheric pressure change,temperature,humidity and wind had no effect on flight behavior of E schultzei,or on their positions within flowers.These findings suggest rainfall is not a serious hazard for them.Perhaps thrips can survive raindrop collisions during flight,as impacts with water droplets are not expected to break the surface tension.

温度对东亚小花蝽捕食西花蓟马效果的影响

探究优势天敌东亚小花蝽成虫对西花蓟马的生物防治捕食潜能,为发挥昆虫天敌资源对害虫的自然防控作用奠定基础。在不同温度和不同猎物密度下,对东亚小花蝽成虫的捕食功能反应和搜寻效应进行研究。结果表明,东亚小花蝽成虫对西花蓟马捕食功能反应符合Holling II模型,各温度条件下东亚小花蝽成虫捕食量与猎物密度呈显著相关性。东亚小花蝽成虫处理1头西花蓟马成虫所需的时间在16℃时最短,为0.1000 d,24℃时最长,为0.4475 d;瞬时攻击率以24℃时最大,为0.8889,32℃时最小,为0.1818;捕食上限以24℃时最大,为18.0头,16℃时最小,为6.5头。东亚小花蝽的日捕食量与西花蓟马密度呈正相关,搜寻效应与西花蓟马密度呈负相关。东亚小花蝽成虫在24℃条件下对西花蓟马有较好的捕食潜能,研究结果为田间充分利用东亚小花蝽防控西花蓟马提供了理论依据。

CopE and TLR6 RNAi-mediated tomato resistance to western flower thrips

The western flower thrips(WFT;Frankliniella occidentalis)is a mesophyll cell feeder that damages many crops.Management of WFT is complex due to factors such as high fecundity,short reproduction time,ability to feed on a broad range of host plants,and broad pesticide resistance.These challenges have driven research into developing alternative pest control approaches for WFT.This study analyzed the feasibility of a biological control-based strategy to manage WFT using RNA interference(RNAi)-mediated silencing of WFT endogenous genes.For the delivery of RNAi,we developed transgenic tomato lines expressing double-stranded RNA(dsRNA)of coatomer protein subunit epsilon(CopE)and Toll-like receptor 6(TLR6)from WFT.These genes are involved in critical biological processes of WFT,and their dsRNA can be lethal to these insects when ingested orally.Adult WFT that fed on the transgenic dsRNAexpressing tomato flower stalk showed increased mortality compared with insects that fed on wild-type samples.In addition,WFT that fed on TLR6 and CopE transgenic tomato RNAi lines showed reduced levels of endogenous CopE and TLR6 transcripts,suggesting that their mortality was likely due to RNAi-mediated silencing of these genes.Thus,our findings demonstrate that transgenic tomato plants expressing dsRNA of TLR6 and CopE can be lethal to F.occidentalis,suggesting that these genes may be deployed to control insecticide-resistant WFT.

四季豆叶挥发性化学物质对西花蓟马趋向行为的影响

为筛选对西花蓟马具有生物活性的四季豆挥发性化学物质,阐明西花蓟马与四季豆之间的化学通讯机制以及开辟防控西花蓟马新的策略和途径提供理论依据。本研究采用固相萃取结合气相色谱质谱联用仪分析了四季豆叶片释放的挥发性物质,利用“Y”型嗅觉仪测定了西花蓟马对不同浓度的5种挥发性化合物的行为反应。结果表明:四季豆叶片中共鉴定出乙酸叶醇酯(36.38%)、2-已烯醛(7.88%)、顺-3-己烯-1-醇(39.81%)和正己醇(4.42%)等52种挥发性化合物,可归为酯类、醛类、烷烃类、环烷烃类等10类。西花蓟马对浓度为10^(-1)~10^(-5)的1-辛烯3-醇、10^(-3)和10^(-5)的乙酸叶醇酯、10^(-2)和10^(-5)的1-戊烯-3-醇及10^(-3)的异戊酸叶醇酯具有一定的趋向反应;对10^(-1)~10^(-2)和10^(-4)~10^(-5)的异戊酸叶醇酯、10^(-2)和10^(-4)的苯乙醛及10^(-1)的1-戊烯-3-醇有一定的忌避反应;对10^(-1)、10^(-2)、10^(-4)的乙酸叶醇酯、10^(-1)和10^(-3)的苯乙醛及10^(-4)的1-戊烯-3-醇没有明显的行为定向反应。本研究结果为阐明西花蓟马与寄主植物四季豆间的化学通讯机制及开发西花蓟马引诱剂或趋避剂奠定理论基础。