小菜蛾中肠氨肽酶N2在昆虫细胞中的表达

利用昆虫细胞-杆状病毒表达系统(Bac-to-Bac baculovirus expression system)表达获得小菜蛾 Plutella xylostella(L.)中肠氨肽酶N2(aminopeptidase N,APN2)蛋白,成功建立了该蛋白在昆虫细胞中的表达体系。将对Cry1Ac毒素敏感和已产生抗性的小菜蛾中肠APN2基因插入表达载体pFAST Bac HTB中,并在草地夜蛾 Spodoptera frugiperda 细胞系(Sf9)中进行了重组表达。聚丙烯酰胺凝胶电泳(SDS-PAGE)及蛋白免疫印迹技术(Western-blotting)结果显示,在107 kDa处有1条特异性蛋白条带。研究表明,小菜蛾中肠APN2基因可在Sf9细胞中成功表达,这为继续研究其功能及抗性的关系奠定了基础。     

The kinetics of insecticide action. Part II: The relationship between the pharmacokinetics of substituted benzyl (1RS)-cis,trans-chrysanthemates and their relative toxicities to mustard beetles (Phaedon cochleariae fab.)

A mathematical model describing insect pharmacokinetics has been applied to data describing the penetration and elimination of a series of pyrethroid analogues [the methylbenzyl (1 RS)-cis, trans-chrysanthemates], applied to mustard beetles. The three parameters of the model (k_p, k_e and λ) have been estimated for each compound. The influence of chemical structure on pharmacokinetics, investigated using canonical correlation analysis, is discussed in relation to relative toxicity and knockdown action. In general, physicochemical properties which result in a slow flow of insecticide through the insect are associated with high toxicity. A large proportion (84%) of the variation in relative toxicity has been explained by resistance to elimination (1/k_e), implying that exposure of the site of action to insecticide is related to the total integral IM₂ for material (M₂) inside the insect. The remaining variation has been attributed to differences in behaviour at receptor sites. An optimum partition value (Δπ₀ ≈ 1.6) seems necessary for maximum pharmacodynamic activity in this series of compounds.     

Quantification of biopesticide activity — a rapid survey of methods and standardization problems1

Worldwide development of IPM techniques and increased interest in microbial pesticides have brought a wide range of registered products onto the market in many countries. Quality control is the key point for manufacturing companies because of the variable biological nature of the products and constraints concerning their storage life. The technical specifications of such microorganism-based preparations are rather difficult for end users to understand and there is an urgent need for standardization. The European Committee for Standardization (ECS) has set up a working group to prepare standard guidelines on assessment of the purity, biological activity and stability of microorganism-based preparations. This paper discusses the measurement of the activity of the three main classes of frequently used microbial pesticides, those of bacterial origin (Bacillus thuringiensis toxin), viral products (insect baculovirus) and fungal products (antagonistic or entomopathogenic).     

粉纹夜蛾离体细胞对Bt Cry1Ac毒素的抗性发展及其交互抗性

以CrylAc活性毒素逐代筛选抗性粉纹夜蛾离体细胞BTI-TN-5B1抗性发展速度呈S形曲线，经56代选择后，抗性比上升至1280倍。在去除选择压力后，抗性比逐渐下降。低水平抗性细胞抗性衰退较快，而高水平抗性细胞抗性衰退较缓慢。抗性比衰退至1．5倍的细胞在复筛后抗性比恢复较快。抗性细胞对苏云金杆菌工程菌GC-91(BtGC-91)、苏云金杆菌鲇泽亚种(B.t.atoazai)和苏云金杆菌库斯塔克亚种(B．t．kurstaki)的复合毒素晶体的活性毒素都具有较高的交互抗性，但对农药无交互抗性，对杆状病毒的敏感性也没发生变化。     

Can the mammalian organoid technology be applied to the insect gut?

Mammalian intestinal organoids are multicellular structures that closely resemble the structure of the intestinal epithelium and can be generated in vitro from intestinal stem cells under appropriate culture conditions. This technology has transformed pharmaceutical research and drug development in human medicine. For the insect gut, no biotechnological platform equivalent to organoid cultures has been described yet. Comparison of the regulation of intestinal homeostasis and growth between insects and mammals has revealed significant similarities but also important differences. In contrast to mammals, the differentiation potential of available insect cell lines is limited and can not be exploited for in vitro permeability assays to measure the uptake of insecticides. The successful development of in vitro models could be a result of the emergence of molecular mechanisms of self‐organization and signaling in the intestine that are unique to mammals. It is nevertheless considered that the technology gap is a consequence of vast differences in knowledge, particularly with respect to culture conditions that maintain the differentation potential of insect midgut cells. From the viewpoint of pest control, advanced in vitro models of the insect midgut would be very desirable because of its key barrier function for orally ingested insecticides with hemolymphatic target and its role in insecticide resistance. © 2020 Society of Chemical Industry     

Expression of δ-endotoxin Cry1EC from an inducible promoter confers insect protection in peanut (Arachis hypogaea L.) plants

BACKGROUND: Spodoptera litura (F.) is a polyphagous foliage insect and a major pest on peanut (Arachis hypogaea L.). Constitutive expression of δ‐endotoxin Cry1EC gives protection against S. litura, as reported earlier. In this study, insect bites and salicylic acid induced high‐level expression of Cry1EC was achieved in peanut. In order to achieve this, the expression of pathogenesis responsive promoter PR‐1a was enhanced by placing it downstream of the CaMV35S promoter in the pCAMBIA 1300 backbone. The resultant promoter CaMV35S(r)PR‐1a expressed a high level of insecticidal δ‐endotoxin Cry1EC. The Gus expression under the control of CaMV35S(r)PR‐1a served as a convenient marker for evaluation of promoter response to different treatments. RESULTS: Transgenic events that showed a very low level of uninduced expression and no expression in seeds were selected. The Cry1EC expression in leaves increased nearly eightfold in the selected event, following induction by salicylic acid. Both the salicylic‐acid‐treated and the S. litura‐bitten leaves showed the highest expression after 2 days. Leaves from salicylic‐acid‐induced transgenic plants caused 100% mortality of S. litura at all stages of larval development. CONCLUSION: The results suggest that high expression of inducible promoters provides a good strategy for the development of safer transgenic food and feed crops. Copyright © 2010 Society of Chemical Industry     

Is acetyl/butyrylcholine specificity a marker for insecticide‐resistance mutations in insect acetylcholinesterase?

Substrate specificity has been widely studied in vertebrate cholinesterases and it has been shown that two phenylalanines in the acyl pocket of acetylcholinesterase govern the acceptance of the acetyl/butyryl moiety of the choline esters. As an insecticide‐resistance mutation has been evidenced in the acyl pocket of Drosophila melanogaster and Musca domestica acetylcholinesterase we investigated the possibility of linking changes in acetyl/butyrylthiocholine specificity with mutations in insect acetylcholinesterase. We thus analyzed the effect of 28 mutations in Drosophila enzyme on acetyl/butyrylthiocholine, N‐methyl/N‐propyl‐carbamates and ethyl/methyl‐paraoxon preference. It appeared that the highest changes on acetyl/butyrylthiocholine and N‐propyl/N‐methyl‐carbamates preference were due to mutations in the acyl pocket. Nevertheless, other insecticide‐resistance mutations, not located in the acyl pocket, also modified these substrate preferences. Moreover, the effect of mutations in the acyl pocket was hidden when some other insecticide‐resistance mutations were combined in the enzyme. Consequently, acetyl/butyrylthiocholine preference alteration cannot be used as a marker to localize a mutation in the insect AChE. © 2000 Society of Chemical Industry     

莲草直胸跳甲气味结合蛋白鉴定及其在触角中的表达分析

为阐明莲草直胸跳甲Agasicles hygrophila对其寄主植物喜旱莲子草Alternanthera philoxeroides的专一性识别过程中气味结合蛋白(odorant-binding protein,OBP)的作用,基于莲草直胸跳甲三代全长转录组测序结果筛选获得其所有OBP基因并进行生物信息学分析,以最大似然法构建莲草直胸跳甲OBP的系统进化树,并通过定量PCR分析这些OBP基因在其触角中的表达量。结果表明,全长转录组测序结果中共鉴定得到53个莲草直胸跳甲AhygOBP基因,所编码蛋白有36个属于Minus-C家族,11个属于Classic家族,5个属于Plus-C家族,1个属于Atypical家族。进化分析结果显示,大部分莲草直胸跳甲AhygOBP与其它目昆虫OBP为直系同源。莲草直胸跳甲AhygOBP基因在触角中的表达分析结果显示,将表达量最低的AhygOBP31作为基准1,表达量最高的依次为AhygOBP53、AhygOBP32、AhygOBP13、AhygOBP28、AhygOBP44、AhygOBP45、AhygOBP29、AhygOBP37、AhygOBP24,其中AhygOBP53的表达量是AhygOBP31的106 000倍。推测这些触角中高表达的AhygOBP可能在宿主植物识别中发挥重要作用。     

Phenology modelling of major insect pests in fruit orchards from biological basics to decision support: the forecasting tool SOPRA*

The forecasting tool SOPRA has been developed with the objective of optimizing timing of monitoring, management and control measures of insect pests in fruit orchards in Switzerland. Applying time‐varying distributed delay approaches, phenology‐models were developed driven by solar radiation, air temperature and soil temperature on hourly basis. Relationships between temperature and stage‐specific development rates for relevant stages of the life cycles were established under controlled laboratory conditions for Dysaphis plantaginea, Hoplocampa testudinea, Cydia pomonella, Grapholita lobarzewskii, Cacopsylla pyri, Rhagoletis cerasi, Anthonomus pomorum and Adoxophyes orana. The implementation of body temperatures in the models is based on habitat selection and biophysical modelling of habitat conditions. In order to validate modelling, phenology predictions were compared with several years of independent field observations. On the basis of local weather data, the age structure of the pest populations is simulated and crucial events for management activities are announced. Through a web interface, the simulation results are made available to consultants and growers ( http://www.sopra.info ) and the latter can be applied as a decision support system for the eight major insect pests of fruit orchards in the alpine valleys and north of the Alps on local and regional scale.     

Isolation,characterization and insect growth inhibitory activity of major turmeric constituents and their derivatives against Schistocerca gregaria (Forsk) and Dysdercus koenigii (Walk)

Curcuminoids, the major colouring constituents of Curcuma longa (turmeric) rhizome powder, comprise mainly three closely related curcumins (I, II and III). A simple method has been devised for their efficient extraction and separation. Their structures have been confirmed by ¹H NMR spectroscopy and unique mass fragmentation pattern. Curcumin‐I, the major constituent has been converted to five alkyl ether derivatives, which have been tested along with the parent compounds and other extractives for insect growth inhibitory activity against Schistocerca gregaria and Dysdercus koenigii nymphs. At 20 µg per nymph, benzene extract and dibutyl curcumin‐I were the most active (60% inhibition) against S gregaria, whereas at 50 µg per nymph these substances exhibited moderate growth‐inhibitory activity (45%) against D koenigii nymphs. At these concentrations, turmeric oil caused 50–60% nymphal mortality in both test insects. The insect control activity of most of the turmeric products was comparable to or better than that of a commercial neem formulation. © 2000 Society of Chemical Industry     

An historical perspective of the ‘Blandford Fly’ (Simulium posticatum Meigen) problem and attempted control of the pest species using Bacillus thuringiensis var. israelensis

This review deals with the biology and control of a biting pest species, Simulium posticatum, which has been responsible for a considerable degree of distress to the human population in the vicinity of the River Stour in Dorset. Each phase of the life cycle of the insect is considered in relation to possible control measures. An account is given of how this information has been combined with the use of Bacillus thuringiensis in a successful, precisely targeted attack on the pest.     

昆虫杆状病毒流行病模拟模型及Java模拟软件(英文)

研究昆虫杆状病毒流行病模拟模型,对确定基因工程改造杆状病毒的主攻方向,明确病毒病田间流行的机制与关键因素,以及制定生物防治策略,均具有重要的理论与实践意义。本研究研制了用于昆虫杆状病毒流行病模拟的数学模型和Java模拟软件,该模型包括描述种群动态的一个微分方程组,描述气温变化、作物生长及病毒动态的若干模型等。模拟软件用工具包JDK和JavaScript开发,由主计算类、图形类、结果显示类、参数输入界面类、警告信息类、主页、用户指南页、版权页、计数页等组成。在参数文件中编入有关作物、病毒、害虫等方面的参数,输入初始的各龄健康、染病虫量、叶面积、病毒密度等,运行后可输出各龄健康、染病及病死的虫量,作物损失,病毒积累等动态,以及图形等等。该模型适用于各种杆状病毒,各种有叶作物,各种食叶性的全变态昆虫。应用该模拟模型,对温度、病毒施用虫龄、病毒施用时间、病毒施用剂量等进行了灵敏度分析,得到了一些重要结论。     

Icerya purchasi (Homoptera: Margarodidae) on Rosmarinus officinalis (Lamiaceae), a new host plant record for Greece

Since July 2008, Rosmarinus officinalis plants in Greece have been observed to be infested by the cottony cushion scale, Icerya purchasi Maskell. This is the first time that I. purchasi has been found on R. officinalis in Greece. Observations made have shown that this scale insect prefers to initially attack the stems of R. officinalis plants.     

Insecticide Resistance in the Western Flower Thrips, Frankliniella occidentalis

The western flower thrips, Frankliniella occidentalis Pergande (Thysanoptera: Thripidae) is a serious pest on a wide range of crops throughout the world. F. occidentalis is difficult to control with insecticides because of its thigmokinetic behaviour and resistance to insecticides. Pesticide resistance can have a negative impact on integrated pest management programmes with chemical control as one of the components. Resistance to a number of different insecticides has been shown in many populations of F. occidentalis. This flower thrips has the potential of fast development of resistance owing to the short generation time, high fecundity, and a haplodiploid breeding system. The mechanisms conferring insecticide resistance in insects can be divided into four levels. First, an altered behaviour can aid the insect to avoid coming into contact with the insecticide. Second, a delayed penetration through the integument will reduce the effect of the insecticide at the target site. Third, inside the insect, detoxification enzymes may metabolise and thereby inactivate the insecticide. Fourth, the last level of resistance mechanisms is alterations at the target site for the insecticide. Knowledge of resistance mechanisms can give information and tools to be used in management of the resistance problem. Recently, studies have been carried out to investigate the underlying mechanisms conferring resistance in F. occidentalis. It appears that resistance in F. occidentalis is polyfactorial; different mechanisms can confer resistance in different populations and different mechanisms may coexist in the same population. Possible resistance mechanisms in F. occidentalis include: reduced penetration, detoxification by P450-monooxygenases, esterases and glutathione S-transferases, and alterations of acetylcholinesterase, the target site for organophosphate and carbamate insecticides. Target site resistance to pyrethroids (knockdown resistance) may also be a resistance mechanism in F. occidentalis.     

Insecticide detoxification indicator strains as tools for enhancing chemical discovery screens

BACKGROUND: Insecticide discovery screens carried out on whole organisms screen for potency resulting from chemical activity at the target site. However, many potentially insecticidal compounds are naturally detoxified in vivo and do not make it to the target site. It is hypothesised that insect strains with their xenobiotic detoxification machinery compromised could be used to identify such compounds that normally fail to show up in screens; these compounds could then be more rationally designed to increase their bioavailability. This strategy was tested with transgenic Drosophila lines with altered expression of Cyp6g1 and Dhr96. RESULTS: It was observed that Cyp6g1 knockdown transgenic lines have increased susceptibility to the test compound imidacloprid, while Dhr96 knockdown transgenic lines are resistant. Evidence was found for a systemic response to xenobiotic exposure, uncovered by piperonyl butoxide treatment and by gene expression profiling. Sex-specific gene expression regulated by DHR96 was also observed. CONCLUSION: The results confirm that this approach to chemical discovery could identify compounds that escape traditional screens. The complexity of the system means that a panel of single and multiple gene knockdown transgenic lines may be required. Copyright © 2011 Society of Chemical Industry     

Definitive confirmation of establishment of Parasaissetia nigra (Nietner) (Hemiptera,Coccidae) in Sicily (Italy), with notes on its association with a new host,Syzygium myrtifolium Walp.

The nigra scale, Parasaissetia nigra (Hemiptera, Coccidae), has occurred for a long time on many ornamental plants in continental Italy. Records of the presence of this polyphagous scale in the island of Sicily have remained unconfirmed. This study confirms the establishment of this damaging insect in Sicily, where the scale has been found on a new host, Syzygium myrtifolium.     

Xylella fastidiosa subspecies and sequence types detected in Philaenus spumarius and in infected plants in France share the same locations

In Europe, the meadow spittlebug Philaenus spumarius is the main known vector of the quarantine bacterium Xylella fastidiosa. So far detection and identification of X. fastidiosa has more often been performed from plant matrices than insects, mainly using a real-time PCR and multilocus sequence typing (MLST) approach. Detection of X. fastidiosa in its insect vectors would enhance knowledge of the epidemiologic situation in France, specifically in the already infected Corsica and Provence-Alpes-Côte d’Azur (PACA) regions. The aim of this study was to validate a methodological approach to detect X. fastidiosa in P. spumarius, analysed individually or in groups of 10, using real-time PCR and MLST, and to apply the approach to more than 4,000 individuals collected between 2015 and 2019 from infected areas. The corresponding results expanded our knowledge of the epidemiology of X. fastidiosa in France: (a) X. fastidiosa subsp. multiplex including the sequence types ST6 and ST7 were identified in the insect vector; (b) the rate of positive insects per infected area was as high as 33.3% in Corsica or 50% in the PACA region; (c) positive adults were found during winter; and (d) the bacterial load in P. spumarius (droplet digital PCR) usually ranged from 10³ to 10⁴ cells per insect, but could be as high as 10⁵ or 10⁶ cells per insect for some individuals (13%). The subspecies and sequence types detected in P. spumarius corresponded to the situation officially reported for plants in the same areas.     

褐飞虱寄生性天敌两索线虫生活史的研究

两索线虫(Amphimermis sp.)的幼虫寄生于褐飞虱、灰飞虱等害虫的体内,使宿主产生一系列的病理变化,直至死亡。本文较详细地报导了湖北省褐飞虱寄生性天敌两索线虫的生活史。在实验室内用感染期幼虫作感染褐飞虱的试验获得成功。根据该虫的生活史和生态习性,在汉阳县的两索线虫孳生田里,采用与水稻高产栽培相结合的保护线虫措施,可以在褐飞虱中等发生量的年份,有效地控制褐飞虱的危害。     

Effect of compost and casing treatments of insecticides against the sciarid Bradysia ocellaris (Diptera: Sciaridae) and on the total yield of cultivated mushrooms,Agaricus bisporus

BACKGROUND: Bradysia ocellaris (Comstock) is one of the major pests of cultivated mushrooms, Agaricus bisporus (Lange) Imbach. The feeding of sciarid fly larvae causes damage to the cultivation substrates, compost and casing. A comparative study of insecticidal treatments incorporated into compost and casing against B. ocellaris was conducted during 2003–2004. Treatments with an organophosphate, diazinon, a pyrazole, fipronil, and an insect growth regulator (IGR), triflumuron, were incorporated into casing. Another IGR, cyromazine, was incorporated into compost. Insecticidal incorporation into compost and casing has been associated with reductions in mushroom yield. Therefore, the effect of these insecticidal treatments on the overall yield was evaluated. RESULTS: A combined treatment, incorporation of cyromazine at 10 mg kg^?1 into compost and of triflumuron at 20 mg kg^?1 into casing, provided 100% control against B. ocellaris. There was no apparent reduction in yield as a result of incorporation of the tested chemicals into either compost or casing. CONCLUSION: The results obtained from this study suggest that incorporation of insecticides into both compost and casing is required to control a moderate to high pressure of insect pests. There were no significant yield reductions as a result of the incorporation of pesticides in the Australian mushroom‐growing system. Copyright © 2009 Society of Chemical Industry