Enhanced mortality of Bemisia tabaci nymphs by Isaria javanica combined with sublethal doses of chemical insecticides

The aim of this current study was to evaluate the mortality of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) nymphs by the combination between the entomopathogenic fungus Isaria javanica (Friedrichs & Bally) Samson & Hywel‐Jones and synthetic chemical insecticides. The bioefficacy of I. javanica and the insect growth regulators named spiromesifen and buprofezin was tested alone and in combination against B. tabaci nymphs under screenhouse conditions. The in vitro compatibility between these two control agents was previously assessed under laboratory conditions. The sublethal concentration (LC₂₅) of these insecticides towards second‐instar nymphs was determined and then mixed with the fungal treatments to investigate the type of interaction. All I. javanica isolates at 5 × 10⁷ conidia/ml inflicted nymphal mortality by up to 62.4%. The insecticides did not influence the germination and mycelial growth of the selected I. javanica isolate CG1282. In general, the insecticide–fungus combinations increased nymphal mortalities in comparison with their single counterparts. Combinations with the fungus and buprofezin or spiromesifen augmented nymphal mortality by 10% and 24%, respectively, in comparison with the fungus alone. Additive interaction was found with the combination of the I. javanica CG1282 at 1 × 10⁶ conidia/ml and spiromesifen at 1.56 ppm, and additive and synergistic interactions were achieved with the fungus at 5 × 10⁶ conidia/ml and spiromesifen at 3.12, 6.25 and 12.5 ppm. Additive interactions were also observed from mixtures of fungus at 5 × 10⁶ and buprofezin at 3.12 and 6.25 ppm. Only combinations of I. javanica with spiromesifen reduced to some extent the mycosis on dead nymphs. The joint action of I. javanica with sublethal doses of these insecticides may be a promising tool to assist in the integrated management system for B. tabaci.     

An age-structured model to evaluate the potential of novel malaria-control interventions: a case study of fungal biopesticide sprays

It has recently been proposed that mosquito vectors of human diseases, particularly malaria, may be controlled by spraying with fungal biopesticides that increase the rate of adult mortality. Though fungal pathogens do not cause instantaneous mortality, they can kill mosquitoes before they are old enough to transmit disease. A model is developed (i) to explore the potential for fungal entomopathogens to reduce significantly infectious mosquito populations, (ii) to assess the relative value of the many different fungal strains that might be used, and (iii) to help guide the tactical design of vector-control programmes. The model follows the dynamics of different classes of adult mosquitoes with the risk of mortality due to the fungus being assumed to be a function of time since infection (modelled using the Weibull distribution). It is shown that substantial reductions in mosquito numbers are feasible for realistic assumptions about mosquito, fungus and malaria biology and moderate to low daily fungal infection probability. The choice of optimal fungal strain and spraying regime is shown to depend on local mosquito and malaria biology. Fungal pathogens may also influence the ability of mosquitoes to transmit malaria and such effects are shown to further reduce vectorial capacity.     

Characterization of biosurfactants as insecticidal metabolites produced by Bacillus subtilis Y9

Biosurfactants have been used for crop protection in integrated pest management programs, as they are generally biodegradable and environmentally friendly. While screening for insecticidal bacteria against green peach aphid, Myzus persicae, we found that a Bacillus isolate, Y9, exhibited strong surface tension activity and produced insecticidal metabolites. The insecticidal metabolites with surface tension activity were extracted from the cell‐free supernatant of Y9 and subjected to repetitive column chromatography and preparative high performance liquid chromatography (HPLC). Based on data from instrumental analyses, the metabolites were identified as surfactin isomers consisting of C₁₄[Leu₇], C₁₄[Val₇] and C₁₅[Leu₇]. The isomers with leucine showed higher insecticidal activity than the isomers with valine. Y9 was capable of producing biosurfactants as insecticidal metabolites against M. persicae, and showed potential for use as a biocontrol agent in an integrated pest management program.     

Paratransgenesis as a potential tool for pest control: review of applied arthropod symbiosis

Research funds for addressing practical plant pest or disease problems are justified by the size of the threat and the financial burden it imposes. When new technology is developed for pest or disease control, regulatory costs to pay for risk assessments make sense when projected income from a new product can be charged to expected income from a future market. When a pest or disease problem affects a minor crop, the research to address regulatory issues does not have such a clear‐cut funding origin. Ironically, a very selective biopesticide designed to address a local pest or disease problem is the ideal form of sustainable pest management, but has the smallest market of any pest control strategy and therefore the smallest amount of financial support. In this sphere of modest financial resources, regulatory needs can force research away from solving the problem at hand to address assessment issues that add considerable cost. When genetic modification is a part of the proposed new strategy, an added burden is placed on the developers. This burden can defy logic and can also come largely from peers, not the public.     

Activity-based probes as a tool for functional proteomic analysis of proteases

Traditional proteomics methodology allows global analysis of protein abundance but does not provide information on the regulation of protein activity. Proteases, in particular, are known for their multilayered post-translational activity regulation that can lead to a significant difference between protease abundance levels and their enzyme activity. To address these issues, the field of activity-based proteomics has been established in order to characterize protein activity and monitor the functional regulation of enzymes in complex proteomes. In this review, we present structural features of activity-based probes for proteases and discuss their applications in proteomic profiling of various catalytic classes of proteases.     

Proteomics as a tool for clinically relevant biomarker discovery and validation

The excitement associated with clinical applications of proteomics was initially focused on its potential to serve as a vehicle for both biomarker discovery and drug discovery and routine clinical sample analysis. Some approaches were thought to be able to "identify" mass spectral characteristics that distinguished between control and disease samples, and thereafter it was believed that the same tool could be employed to screen samples in a high-throughput clinical setting. However, this has been difficult to achieve, and the early promise is yet to be fully realized. While we see an important place for mass spectrometry in drug and biomarker discovery, we believe that alternative strategies will prove more fruitful for routine analysis. Here we discuss the power and versatility of 2D gels and mass spectrometry in the discovery phase of biomarker work but argue that it is better to rely on immunochemical methods for high-throughput validation and routine assay applications.     

Genetics and evolution of resistance to insecticides

The evolution of resistance to insecticides has become a serious problem world-wide. It is important to identify patterns of insecticide use whereby insecticides can be used in integrated pest management programmes to help control insect numbers, but in such a manner that the evolution of resistance to insecticides will be retarded. The principal mechanisms of insecticide action and of resistance to these are reviewed. Some generalizations that can be made about the evolution of resistance are examined. In general, to control resistance it appears better to use an intense dose of non-persistent pesticides over a circumscribed area. Some features of the problem where population genetics and evolutionary theory might contribute to controlling resistance are discussed.     

A microbial culture with oxygen-sensitive product distribution as a potential tool for characterizing bioreactor oxygen transport

The dissolved oxygen (DO) level has been shown to have a profound effect on the product distribution of a Bacillus subtilis culture, with acetoin being excreted with DO above 100 parts per billion (ppb) and butanediol below 100 ppb. The product concentration ratio changed rapidly in the 80-90 ppb range. Switching from one oxygen level to another caused one already accumulated product to be converted to the other in a reversible manner. Rates of change of 0.5-1 g/L h enabled detection within 10 min. Detection sensitivity is enhanced because the ratio of two concentrations can be measured. Remarkably sensitive to mixing rates, the culture responded to changes in stirring speed during experiments in which the dissolved oxygen was controlled at a constant level with a novel control system. Thus, the culture is capable of detecting dead zones in relatively well-mixed reactors and oxygen gradients in column and tubular reactors. High-viscosity effects can also be investigated since the culture grows well in xanthan gum solutions. Preliminary kinetic model development indicates that a useful model for simulating reactor mixing and transport effects can be developed to aid in the planning of experiments.     

Use of baculoviruses as biological insecticides

Naturally occurring baculoviruses can be used to control a wide range of insect pests. Most baculoviruses are used as biopesticides, that is, they are sprayed onto high-density pest populations in a manner akin to the use of synthetic chemical pesticides. However, other strategies that use the biological features of the viruses are also possible and should increase as we expand our knowledge of baculovirus ecology. In order to develop a baculovirus control program, several areas need to be studied before progressing to large scale field studies and commercialization. These range from laboratory efficacy testing and the development of production systems to detailed study of pest behavior and the development of appropriate application strategies.     

The International Proteomics Tutorial Programme (IPTP): a teaching tool box for the proteomics community

The most critical functions of the various proteomics organisations are the training of young scientists and the dissemination of information to the general scientific community. The education committees of the Human Proteome Organisation (HUPO) and the European Proteomics Association (EuPA) together with their national counterparts are therefore launching the International Proteomics Tutorial Programme to meet these needs. The programme is being led by Peter James (Sweden), Thierry Rabilloud (France) and Kazuyuki Nakamura (Japan). It involves collaboration between the leading proteomics journals: Journal of Proteome Research, Journal of Proteomics, Molecular and Cellular Proteomics, and Proteomics. The overall level is aimed at Masters/PhD level students who are starting out their research and who would benefit from a solid grounding in the techniques used in modern protein-based research. The tutorial program will cover core techniques and basics as an introduction to scientists new to the field. At a later stage the programme may be expanded with a series of more advanced topics focussing on the application of proteomics techniques to biological problem solving. The entire series of articles and slides will be made freely available for teaching use at the Journals and Organisations homepages and at a special website, www.proteomicstutorials.org.     

Proteomics as a tool for the investigation of seafood and other marine products

The state-of-the-art and future trends of the application of proteomics to seafood and other marine products are reviewed. Consumers' demands for seafood products have increased in the recent years and this situation has underlined the need to guarantee the safety, traceability, authenticity, and health benefits of such products. The increasing presence of commercially available aquaculture products has also prompted the seafood industry to face newer challenges. In this sense, a review of the present status and perspectives of the application of proteomics in the development of newer biotechnology products of marine origin is given.     

Proteomics and metabolomics in biomarker discovery for cardiovascular diseases: progress and potential

Introduction: The process of discovering novel biomarkers and potential therapeutic targets may be shortened using proteomic and metabolomic approaches.

Areas covered: Several complementary strategies, each one presenting different advantages and limitations, may be used with these novel approaches. In vitro studies show how cells involved in cardiovascular disease react, although the phenotype of cultured cells differs to that occurring in vivo. Tissue analysis either in human specimens or animal models may show the proteins that are expressed in the pathological process, although the presence of structural proteins may be confounding. To identify circulating biomarkers, analyzing the secretome of cultured atherosclerotic tissue, analysis of blood cells and/or plasma may be more straightforward. However, in the latter approach, high-abundant proteins may mask small molecules that could be potential biomarkers. The study of sub-proteomes such as high-density lipoproteins may be useful to circumvent this limitation. Regarding metabolomics, most studies have been performed in small populations, and we need to perform studies in large populations in order to discover robust biomarkers.

Expert commentary: It is necessary to involve the clinicians in these areas to improve the design of clinical studies, including larger populations, in order to obtain consistent novel biomarkers.     

Isolation and characterization of a Serratia marcescens with insecticidal activity from Polyphylla olivieri (Col.: Scarabaeidae)

Members of the genus Serratia are known for their abilities to infect insects. In this study, a red‐pigmented S. marcescens was isolated and characterized from the infected larvae of Polyphylla olivieri using bacterial cultivation, phylogenetic analysis as well as bioassays against larvae of the two insect pests, Plodia interpunctella and Ephestia kuehniella. Comparative 16S rRNA and groEL gene sequence BLAST analyses strongly suggested that the isolated strain should be placed in the genus Serratia, sharing high sequence similarities with several strain of S. marcescens associated with insects. Phylogenetic analysis placed the isolated bacterium with other S. marcescens bacteria in a clade with high bootstrapping values. To assess pathogenicity of the S. marcescens isolate, the bacterial cells were either injected into the haemolymph of the fifth‐instar larvae or added to the diets of insects. Survival curves of the control insects and those challenged with six different concentrations of S. marcescens showed that the S. marcescens isolate significantly reduced survival rates of the larvae. The LC₅₀s of the bacterium on P. interpunctella and E. kuehniella were 1992.26 and 1.09 × 10⁴ (CFU/μl) for injection bioassays at 6 h post‐injection, and 4.48 × 10⁴ and 1.96 × 10⁵ (CFU/10 μl) for feeding bioassays at 24 h post‐feeding, respectively. Injection of the bacterial culture supernatant into the larvae led to continuous bleeding from the site of injection, while injection of heat‐treated culture supernatant of the bacterium did not cause continuous bleeding. Together, our results showed the possibility of using this S. marcescens isolate in microbial control of the insect pests after addressing the safety concerns. Moreover, it might be considered as a source of useful bioactive molecules and genes with application in insect control and biotechnology via developing insect‐resistant plants.     

Ants as mealybug detectors: a novel tool for monitoring Planococcus ficus infestation based on ant behaviour

1. Vineyards are economically valuable agroecosystems that have spread to all continents. As such, sustainable management of their pests is an important goal. Mealybugs are serious pests of vines with Planococcus ficus (VMB) being the most problematic worldwide. Mealybugs are attended by different ant species, whose trophobiotic relationship is often considered damaging since some ant species may offer effective protection from natural enemies in exchange for honeydew.
2. We tested whether this trophobiosis can be used as a VMB monitoring tool, developing a protocol to evaluate infestation on the plants based on ant behaviour (Ant method). We compared this new protocol with the conventional one, consisting in visual counting of VMBs on infested leaves (Leaf method).
3. Our results demonstrated that the Ant method yielded significant advantages over the Leaf method by: (i) allowing to detect VMB infestation on individual plants much earlier; and (ii) allowing to keep track of VMB presence after pest treatments.
4. The Ant method is proposed as a valid complementary tool for integrated pest management in vineyards and its successful achievement encourage searching for further agricultural contexts in which ants may be revaluated as a monitoring tool.

     

Protease inhibitors:recent advancement in its usage as a potential biocontrol agent for insect pest management

Plant derived protease inhibitors(PIs)are a promising defensin for crop im-provement and insect pest management.Although agronomist made significant efforts in utilizing PIs for managing insect pests.the potentials of PIs are still obscured.Insect ability to compensate nutrient starvation induced by dietary PI feeding using different strategies,that is,overexpression of PI-sensitive protease,expression of PI-insensitive proteases,degradation of PI,has made this innumerable collection of PIs worthless.A practical challenge for agronomist is to identify potent PI candidates,to limit insect compensatory responses and to elucidate insect compensatory and resistance mechanisms activated upon herbivory.This knowledge could be further efficiently utilized to identify potential targets for RNAi-mediated pest control.These vital genes of insects could be functionally anno-tated using the advanced gene-editing technique,CRISPR/Cas9.Contemporary research is exploiting different in silico and modern molecular biology techniques to utilize PIs in controlling insect pests efficiently.This review is structured to update recent advancements in this field,along with is chronological background.     

Proteomics as a tool to monitor plant-microbe endosymbioses in the rhizosphere

In recent years, outstanding molecular approaches have been used to investigate genes and functions involved in plant-microbe endosymbioses. In this review, we outline the use of proteomic analysis, based on two-dimensional electrophoresis and mass spectrometry, to characterize symbiosis-related proteins. During the last decade, proteomics succeeded in identifying about 400 proteins associated with the development and functioning of both mycorrhizal and rhizobial symbioses. Further progress in prefractionation procedures is expected to allow the detection of symbiotic proteins showing low abundance or being present in certain cell compartments.     

Proteomics in Alzheimer's disease: insights into potential mechanisms of neurodegeneration

Proteomics involves the identification of unknown proteins following their separation, often using two-dimensional electrophoresis, digestion of particular proteins of interest by trypsin, determination of the molecular weight of the resulting peptides, and database searching to make the identification of the proteins. Application of proteomics to Alzheimer's disease (AD), the major dementing disorder of the elderly, has just begun. Differences in protein expression and post-translational modification (mostly oxidative modification) of proteins from AD brain and peripheral tissue, as well as in brain from rodent models of AD, have yielded insights into potential molecular mechanisms of neurodegeneration in this dementing disorder. This review surveys the proteomics studies relevant to AD, from which new understandings of the pathology, biochemistry, and physiology of AD are beginning to emerge.     

Evaluation of organic insecticides for management of spotted‐wing drosophila (Drosophila suzukii) in berry crops

Spotted‐wing drosophila, Drosophila suzukii (Matsumura), is an invasive pest affecting fruit production in many regions of the world. Insecticides are the primary tactic for controlling D. suzukii in organic as well as conventional production systems. Organic growers have a greater challenge because fewer insecticides are approved for use in organic agriculture. The most effective organically approved product is spinosad, but alternatives are needed because of label restrictions limiting the number of applications per year, toxicity to beneficial arthropods and the risk of developing resistance. We evaluated several organically approved insecticides against D. suzukii in laboratory assays and field trials conducted on organic blueberry and raspberry farms. Spinosad was consistently the most effective insecticide, but a few other insecticides such as azadirachtin + pyrethrins, Chromobacterium subtsugae and sabadilla alkaloids showed moderate activity. None of the treatments had long residual activity. Mortality started to decline by 3 days after treatment, and by 5 days after application, the treatments were not different from the controls. These products may be useful in rotation programmes, necessary for reducing reliance on spinosad and mitigating resistance. Cultural and biological control approaches are needed in fruit production for D. suzukii management, but insecticides will likely continue to be the dominant management tactic while these other approaches are being optimized and adopted.