scholarly journals Mechanisms of Cell Entry by dsRNA Viruses: Insights for Efficient Delivery of dsRNA and Tools for Improved RNAi-Based Pest Control

2021 ◽  
Vol 12 ◽  
Author(s):  
Luc Swevers ◽  
Dimitrios Kontogiannatos ◽  
Anna Kolliopoulou ◽  
Feifei Ren ◽  
Min Feng ◽  
...  

While RNAi is often heralded as a promising new strategy for insect pest control, a major obstacle that still remains is the efficient delivery of dsRNA molecules within the cells of the targeted insects. However, it seems overlooked that dsRNA viruses already have developed efficient strategies for transport of dsRNA molecules across tissue barriers and cellular membranes. Besides protecting their dsRNA genomes in a protective shell, dsRNA viruses also display outer capsid layers that incorporate sophisticated mechanisms to disrupt the plasma membrane layer and to translocate core particles (with linear dsRNA genome fragments) within the cytoplasm. Because of the perceived efficiency of the translocation mechanism, it is well worth analyzing in detail the molecular processes that are used to achieve this feat. In this review, the mechanism of cell entry by dsRNA viruses belonging to the Reoviridae family is discussed in detail. Because of the large amount of progress in mammalian versus insect models, the mechanism of infections of reoviruses in mammals (orthoreoviruses, rotaviruses, orbiviruses) will be treated as a point of reference against which infections of reoviruses in insects (orbiviruses in midges, plant viruses in hemipterans, insect-specific cypoviruses in lepidopterans) will be compared. The goal of this discussion is to uncover the basic principles by which dsRNA viruses cross tissue barriers and translocate their cargo to the cellular cytoplasm; such knowledge subsequently can be incorporated into the design of dsRNA virus-based viral-like particles for optimal delivery of RNAi triggers in targeted insect pests.

2021 ◽  
Vol 70 ◽  
pp. 158-166
Author(s):  
Qiang Zhang ◽  
Wei Dou ◽  
Clauvis Nji Tizi Taning ◽  
Guy Smagghe ◽  
Jin-Jun Wang

1996 ◽  
Vol 14 (1) ◽  
pp. 22-26 ◽  
Author(s):  
D. Casey Sclar ◽  
Whitney S. Cranshaw

Abstract Use of systemic insecticides that can be injected either into the root system or trunk of woody plants provides several potential advantages, notably in control of drift during application. Recently, new classes of insecticides with systemic activity have been developed, which may supplant the organophosphate and carbamate systemic insecticides that have previously been available. To evaluate their potential to control insects affecting shade trees, studies were conducted using imidacloprid and abamectin on elm. Soil injections of imidacloprid appeared particularly effective, controlling all three of the target pest species in this study (elm leaf beetle, European elm scale, elm leaf aphid). Both imidacloprid and abamectin also were effective against at least some elm insects when injected into trunks. Persistence of irnidacloprid was unusually long, providing second season control of all elm insect pests, although root uptake following soil injections was slow.


2006 ◽  
Vol 15 (6) ◽  
pp. 667-672 ◽  
Author(s):  
Yun-Soo Kim ◽  
Hirotaka Uefuji ◽  
Shinjiro Ogita ◽  
Hiroshi Sano

Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2290 ◽  
Author(s):  
Mariano Cáceres ◽  
Eduardo Guzmán ◽  
Agustín Alvarez-Costa ◽  
Francisco Ortega ◽  
Ramón G. Rubio ◽  
...  

Synthetic insecticides have been used for a long time as one of the most effective tools for insect pest control. However, the re-emergence of insect pests and their fast development of resistance, as has occurred for pyrethroid-resistant bed bugs Cimex lectularius L., make it necessary to develop new and safe strategies for effective pest control. This has fostered the research on new eco-sustainable formulations based on essential oils, which allows reducing the impact associated with the intensive use of synthetic insecticides on the environment and their effects on human health. This research explores the stability of water/eugenol/ethanol surfactantless emulsions loaded with imidacloprid (0.003 wt%), and their toxicity against a resistant bed bug strain. The results have shown that these emulsions enable the solubilization of a poorly water-soluble drug, such as the imidacloprid, without any significant modification of their stability. Furthermore, the application of the obtained formulations against the pyrethroid-resistant bed bug results in mortality in the 50–85% range upon topical and spray applications, with the increase of the eugenol content enhancing the effectiveness of the formulations. It may be expected that the ternary water/eugenol/ethanol mixtures could be further developed in the preparation of ready to use formulations, enabling the dispersion of insecticides for pest control.


1988 ◽  
Vol 17 (1) ◽  
pp. 30-34 ◽  
Author(s):  
R. G. Mckinlay

The international importance of the potato crop needs no stressing and its protection from insect pests is correspondingly important. This article reviews the wide variety of control methods currently in use. In present circumstances integrated pest control methods are desirable on environmental grounds, but in practice the careful monitoring required makes this difficult for the individual grower.


2016 ◽  
Vol 1 (2) ◽  
pp. 55
Author(s):  
. Nurindah ◽  
Dwi Adi Sunarto ◽  
. Sujak

<p>Pengelolaan serangga hama dalam good agricultural practices (GAP) menerapkan cara-cara memproduksi tanaman yang berkualitas dengan menggunakan metode-metode pengelolaan serangga hama yang dapat meningkatkan keragaman genetik, keanekaragaman hayati dan habitatnya, serta terhadap struktur sosial dan komunitas pedesaan. Strategi ‘tolak-tarik’ (‘push-pull’ strategy) merupakan salah satu teknik pengenda-lian hama yang berprinsip pada komponen pengendalian non-toksik, sehingga dapat diintegrasikan dengan metode-metode lain yang dapat menekan perkembangan populasi hama dengan meningkatkan peran mu-suh alami pada pertanaman. Penelitian tanaman perangkap untuk pengendalian serangga tanaman temba-kau cerutu besuki dilaksanakan di Desa Antirogo, Kecamatan Sumbersari, Jember pada bulan Agustus–De-sember 2008. Pada penelitian ini digunakan tanaman jarak kepyar, sorgum, dan kacang hijau sebagai ta-naman penarik yang ditanam secara berlajur sebanyak satu atau dua baris di antara delapan baris tanaman tembakau. Sebagai pembanding adalah tanaman tembakau monokultur dengan penyemprotan insektisida secara berjadwal setiap empat hari sejak 10–50 HST dan petak kontrol, yaitu tanaman monokultur tanpa pe-ngendalian hama sama sekali. Penelitian disusun dalam rancangan acak kelompok dengan lima perlakuan yang diulang lima kali. Penelitian ini bertujuan untuk memilih tanaman perangkap yang dapat digunakan da-lam program pengendalian hama cerutu besuki secara terpadu. Hasil penelitian menunjukkan bahwa tanam-an jarak kepyar, sorgum, dan kacang hijau dapat digunakan sebagai tanaman perangkap, sehingga populasi hama pada tembakau dapat ditekan hingga 50% dan diperoleh produksi daun basah (8,62–9,17 ton/ha vs 8,42 ton/ha) dan kerosok (1,01–1,07 ton/ha vs 0,96 ton/ha) dengan mutu yang lebih baik dibandingkan kontrol (indeks mutu: 62,5–64,4 vs 62,1). Penggunaan kacang hijau memberikan produksi kerosok dengan mutu baik tertinggi, sehingga memberikan penerimaan yang lebih tinggi dibandingkan perlakuan lain. Pe-nyemprotan insektisida secara berjadwal untuk mengendalikan serangga hama tembakau cerutu besuki na-oogst merupakan tindakan pengendalian yang tidak efektif dan juga tidak efisien, karena sasaran serangga hama tidak tepat, sehingga terjadi pemborosan biaya input.</p><p> </p><p>Pest management in good agricultural practices concept use methods of qualified crop production processes with considering increasing genetic diversity, biodiversity and its habitat as well as social structure and village community. Push-and-pull strategy is a pest control method with a non-toxic method principal so that it can be integrated with other methods to suppress pest population and increase natural enemies’ populationin the ecosystems. Research on trap crops used for controlling insect pests on besuki-cigar tobaccowas conducted on besuki-cigar tobacco fields planted after rice (na-oogst) in Jember on August–December2008. In this research activity we used castor, sorghum, and mungbean as trap crops, each was intercroppedin one or two rows between eight rows of tobacco plants. We used monoculture tobacco plants withscheduled sprays of chemical insecticide, i.e. 4 days-spray interval on 10–50 days after planting and controlplots without any insect pest control for comparison with the use of trap crops. The research was arrangedin randomized block design with five treatments and five replicates. The aim of the research is to choose asuitable trap crop used in pest management of besuki cigar tobacco. The results showed that castor, sorghum,and mungbean could be use as trap crops to suppress insect pests population up to 25% on tobaccoplants and would give leaf production (1.01–1.07 ton/ha vs 0,96 ton cured leaves/ha) with a better quality(quality index: 62.5–64.4 vs 62.1) than those of control. Mungbean is the best trap crop as it gives a highestleaf production with a better quality, so that gives a better income than those of other treatments. Scheduledchemical insecticide sprays to control insect pest on na-oogst-besuki cigar tobacco was not either effectiveor efficient, because the target pest was not right, so that causing a wasteful input cost.</p>


2021 ◽  
Author(s):  
Shudh Kirti Dolma ◽  
Prithvi Pal Singh ◽  
S. G. Eswara Reddy

Abstract Aphid, Aphis craccivora Koch (Hemiptera: Aphididae) is a major sap-sucking insect pest of leguminous crops and also transmit plant viruses leading to economic yield loss. Insecticidal activities of T. sebifera have not been reported against A. craccivora and other insect pests till date. In this study, residual toxicity of leaf/bark extracts, seed oil, fractions, isolated compounds and its combinations; synergistic activity of leaf/ bark extract with seed oil and its enzyme inhibition activities against A. craccivora was studied. Among extracts, ethanolic bark extract 80% (LC50=5115.98 mg L-1) was more effective against A. craccivora than other extracts. Among fractions, n-hexane fraction of leaf (LC50=425.73 mg L-1) and ethyl acetate fraction of bark (LC50=813.45mg L-1) was more effective. Among compounds, gallic acid was most effective (LC50=1303.68 mg L-1) than shikimic acid and quercetin (LC50=1725.09 and 1855.93 mg L-1, respectively). Seed oil (LC50=850.94 mg L-1) is more superior than extracts/fractions/compounds. All the combinations showed toxicity and synergistic activity. Leaf/bark extracts and seed oil (0.25-2 mg L-1) significantly inhibits the AChE and GST activity in A. craccivora. Based on field bio-efficacy studies, the leaf extract/seed oil or their combinations can be recommended for development of botanical formulation for the control of aphid.


2021 ◽  
Vol 4 (4) ◽  
pp. 484-491
Author(s):  
A. Muhammad ◽  
M. A. Kashere

The search for reducing risks associated with the use of chemicals has necessitated use of pest control using plant products. Neem is perhaps one of the most useful medicinal plant in the tropics. Each part of the tree has huge insecticidal property. Apart from the chemistry of the neem compounds, considerable progress has been achieved regarding the biological activity and insecticidal uses of neem. It is now considered as a valuable source of unique natural product for botanical insecticides against various pests. Farmers in tropical countries commonly used its leaves, seed kernels and its oil in various forms. Neem is utilized in form of powders, extracts or as an emulsifiable oil. Researches had shown that neem consists of pesticidal ingredients called triterpenes (limonoids). Trials conducted on the effect of neem products revealed secondary metabolites affect metabolic processes that include feeding and oviposition deterrence; metamorphosis inhibition, protein synthesis, changes in biological fitness, impaired sexual communication and chitin synthesis. Azadirachtin in particular interferes with chemoreception and exerts direct negative effects on many insect tissues such as muscles and digestive epithelial cells as well as insect mortality. Neem derived biopesticides are cheap, available in all ecological zone, posed no hazard to applicator and the environment as it is biodegradable. Insects such as Aphids, African migratory locust, legume pod-borer, coreid bugs and storage insect pests such as cowpea seed bruchid were controlled using neem. Sustainable insect pest control can be achieved with the use of neem based biopesticides.


Insects ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 189
Author(s):  
Ivana Tlak Gajger ◽  
Showket Ahmad Dar

In this review, we describe the role of plant-derived biochemicals that are toxic to insect pests. Biotic stress in plants caused by insect pests is one of the most significant problems, leading to yield losses. Synthetic pesticides still play a significant role in crop protection. However, the environmental side effects and health issues caused by the overuse or inappropriate application of synthetic pesticides forced authorities to ban some problematic ones. Consequently, there is a strong necessity for novel and alternative insect pest control methods. An interesting source of ecological pesticides are biocidal compounds, naturally occurring in plants as allelochemicals (secondary metabolites), helping plants to resist, tolerate or compensate the stress caused by insect pests. The abovementioned bioactive natural products are the first line of defense in plants against insect herbivores. The large group of secondary plant metabolites, including alkaloids, saponins, phenols and terpenes, are the most promising compounds in the management of insect pests. Secondary metabolites offer sustainable pest control, therefore we can conclude that certain plant species provide numerous promising possibilities for discovering novel and ecologically friendly methods for the control of numerous insect pests.


Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 346
Author(s):  
Marc J. B. Vreysen ◽  
Adly M. M. Abd-Alla ◽  
Kostas Bourtzis ◽  
Jeremy Bouyer ◽  
Carlos Caceres ◽  
...  

The Joint FAO/IAEA Centre (formerly called Division) of Nuclear Techniques in Food and Agriculture was established in 1964 and its accompanying laboratories in 1961. One of its subprograms deals with insect pest control, and has the mandate to develop and implement the sterile insect technique (SIT) for selected key insect pests, with the goal of reducing the use of insecticides, reducing animal and crop losses, protecting the environment, facilitating international trade in agricultural commodities and improving human health. Since its inception, the Insect Pest Control Laboratory (IPCL) (formerly named Entomology Unit) has been implementing research in relation to the development of the SIT package for insect pests of crops, livestock and human health. This paper provides a review of research carried out between 2010 and 2020 at the IPCL. Research on plant pests has focused on the development of genetic sexing strains, characterizing and assessing the performance of these strains (e.g., Ceratitis capitata), elucidation of the taxonomic status of several members of the Bactrocera dorsalis and Anastrepha fraterculus complexes, the use of microbiota as probiotics, genomics, supplements to improve the performance of the reared insects, and the development of the SIT package for fruit fly species such as Bactrocera oleae and Drosophila suzukii. Research on livestock pests has focused on colony maintenance and establishment, tsetse symbionts and pathogens, sex separation, morphology, sterile male quality, radiation biology, mating behavior and transportation and release systems. Research with human disease vectors has focused on the development of genetic sexing strains (Anopheles arabiensis, Aedes aegypti and Aedes albopictus), the development of a more cost-effective larvae and adult rearing system, assessing various aspects of radiation biology, characterizing symbionts and pathogens, studying mating behavior and the development of quality control procedures, and handling and release methods. During the review period, 13 coordinated research projects (CRPs) were completed and six are still being implemented. At the end of each CRP, the results were published in a special issue of a peer-reviewed journal. The review concludes with an overview of future challenges, such as the need to adhere to a phased conditional approach for the implementation of operational SIT programs, the need to make the SIT more cost effective, to respond with demand driven research to solve the problems faced by the operational SIT programs and the use of the SIT to address a multitude of exotic species that are being introduced, due to globalization, and established in areas where they could not survive before, due to climate change.


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