Pest

Plant-mediated RNA interference (RNAi) shows great potential in crop protection. It relies on plants stably expressing double-stranded RNAs (dsRNAs) that target essential genes in pest insects. Practical application of this strategy is challenging because producing sufficient amounts of stable dsRNA in plants has proven to be difficult to achieve with conventional transgenesis. In addition, many insects do not respond to exogenously applied dsRNAs, either degrading them or failing to import them into the cytoplasm...

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There is surprisingly little information on adaptive responses of pests and disease vectors to climatic stresses even though the short generation times and large population sizes associated with pests make rapid adaptation likely. Most evidence of adaptive differentiation has been obtained from geographic comparisons and these can directly or indirectly indicate rates of adaptation where historical data on invasions are available. There is very little information on adaptive shifts in pests detected through molecular comparisons even though the genomes of many pests are now available and can help to identify markers underlying adaptation...

Gene flow via immigration affects rate of evolution of resistance to a pest management tactic, while emigration from a resistant population can spread resistance alleles spatially. Whether resistance detected across the landscape reflects ongoing de novo evolution in different hotspots or spread from a single focal population can determine the most effective mitigation strategy. Pest dispersal dynamics determine the spatio-temporal scale at which mitigation tactics must be applied to contain or reverse resistance in an area...

Insect pathogens are widely used as a tool for sustainable pest management. Their complex mode of action was thought to make them immune to the evolution of resistance; however, several examples of field-based resistance to the bacterium Bacillus thuringiensis and a granulovirus have been recorded. Here I review the scenarios where resistance has evolved and discuss the likelihood of it occurring in other entomopathogens. I highlight recent research on the factors which might influence the evolution of resistance to insect pathogens, including the role of pathogen diversity, host nutrition and transgenerational effects...

Insecticides are an invaluable pest management tool and anthropogenic stressors of widespread environmental occurrence that are subject to biased perceptions based on the targeted application, market value of use, and regulatory requirements. As a result, short-term and simplistic efforts focusing on lethal effects toward individual species and populations prevail. Holistic and comprehensive studies exploring rather common sublethal insecticide exposures are rare, particularly considering their potential role in structuring populations and communities in diverse environmental settings and potentially interfering in a range of ecological interactions...

Insecticide resistance is a serious economic problem that jeopardizes sustainability of chemical control of herbivorous insects and related arthropods. It can be viewed as a specific case of adaptation to toxic chemicals, which has been driven in large part, but not exclusively, by the necessity for insect pests to tolerate defensive compounds produced by their host plants. Synthetic insecticides may simply change expression of specific sets of detoxification genes that have evolved due to ancestral associations with host plants...

For over 100 years it has been recognized that insect pests evolve resistance to chemical pesticides. More recently, managers have advocated restrained use of pesticides, crop rotation, the use of multiple pesticides, and pesticide-free sanctuaries as resistance management practices. Game theory provides a conceptual framework for combining the resistance strategies of the insects and the control strategies of the pest manager into a unified conceptual and modelling framework. Game theory can contrast an ecologically enlightened application of pesticides with an evolutionarily enlightened one...

Several strategies involving refuge have been proposed for delaying insect resistance to Bt crops. The report was focused on the unstructured 'natural' refuges that contain plants naturally presented as part of the cropping system in the form of non-Bt plants that differ from Bt plant species, or wild host plants of the target pests. The cases of natural refuges applied in different countries were analyzed, and the factors that favor their success are discussed. The results indicate that the effectiveness of a natural refuge strategy depends on the biological characteristics of the target pest, the spatial and temporal distribution and abundance of the host plants in the agricultural system and the quality of the host plants for the pest species...

Plant-mediated RNA interference (RNAi) shows great potential in crop protection. It relies on plants stably expressing double-stranded RNAs (dsRNAs) that target essential genes in pest insects. Practical application of this strategy is challenging because producing sufficient amounts of stable dsRNA in plants has proven to be difficult to achieve with conventional transgenesis. In addition, many insects do not respond to exogenously applied dsRNAs, either degrading them or failing to import them into the cytoplasm...

To understand the history development and changes of Citri Grandis Exocarpium and initially establish its standard system after exploring the historical origins and modern development of Citri Grandis Exocarpium. In CNKI, Wanfang database and other academic search platforms were searched for literature on Citri Grandis Exocarpium and Chinese medicine standard system； the books related to its modern cultivation techniques and processing technology were also accessed, and after combining with the actual situation analysis, the prospective design of the standard system of Citri Grandis Exocarpium was finally established with research conclusion...

Neoleucinodes elegantalis (Guenée) (Lepidoptera: Crambidae) is one of the major pests of solanaceous plants in South America. It is considered a great threat by the European and Mediterranean Plant Protection Organization due to the serious economic damage that it causes on tomato farms; therefore, controlling this pest is a challenging task in South America. Controlling N. elegantalis at the egg stage is the best way to prevent it from damaging crops; however, thorough studies about the effectiveness of chemicals on the different life stages of this insect pest are lacking...

The brown planthopper (BPH) is the most devastating insect pest of rice. The rice gene BPH15 confers resistance to BPH. MicroRNAs (miRNAs) regulate a spectrum of development and defense response processes in plants. In this study, we analyzed six miRNA profiles of a BPH15 introgression line (P15) and a susceptible recipient line (PC) at three time points (0 h, 6 h and 48 h) after BPH attack, and identified 464 known miRNAs and 183 potential novel miRNAs. Before the BPH feeding, we identified 23 miRNAs differentially expressed in P15 and PC...

A novel chemotype insecticide flupyrimin (FLP) [N-[(E)-1-(6-chloro-3-pyridinylmethyl)pyridin-2(1H)-ylidene]-2,2,2-trifluoroacetamide], discovered by Meiji Seika Pharma, has unique biological properties including outstanding potency to imidacloprid (IMI)-resistant rice pests together with superior safety toward pollinators. Intriguingly, FLP acts as a nicotinic antagonist in American cockroach neurons and [3H]FLP binds to the multiple high-affinity binding components in house fly nicotinic acetylcholine (ACh) receptor (nAChR) preparation...

Improving natural pest control by promoting high densities of predatory mites (Acari: Phytoseiidae) is an effective way to prevent damage by pest mites (e.g., Eriophyidae, Tetranychidae) and other arthropod taxa that can cause serious damage to vineyards. Here, we investigate the influence of innovative management on predatory mite densities. We compare (i) full versus reduced fungicide applications and (ii) minimal pruning versus a traditional trellis pruning system in four fungus-resistant grapevine varieties...

The predator mite Iphiseiodes zuluagai Denmark & Muma is an important biological-control agent of mite pests, and it is one of the most common species found in citrus orchards. This study assessed, under laboratory conditions, the toxicity and duration of the harmful effects of five insecticides, the three pyrethroids deltamethrin, esfenvalerate and lambda-cyhalothrin, and the two neonicotinoids imidacloprid and thiamethoxam on I. zuluagai. Furthermore, we estimated the life-table parameters of the predator...

The mirid bug Apolygus lucorum (Meyer-Dür) has become a major pest in cotton fields and has led to significant yield losses due to the widespread use of transgenic Bt cotton in China. Eight neonicotinoid seed treatments were investigated to determine their effects on the management of A. lucorum in cotton fields. All neonicotinoid seed treatments reduced the cotton damage caused by A. lucorum, and nitenpyram at the rate of 4 g/kg seed showed the most favorable efficacy in suppressing A. lucorum populations throughout the cotton seedling stage...

Insect pests belonging to the genus Callosobruchus are the major cause of damage to stored pulse crops. Recently, nanotechnology has emerged as a promising tool for pest control. In the present study, we report for the first time the synthesis and biological evaluation of Bacillus thuringiensis coated zinc oxide nanoparticles (Bt-ZnO NPs) on the pulse beetle, Callosobruchus maculatus. The biologically synthesized Bt-ZnO NPs were extensively characterized using UV-Vis spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM) and Zeta potential...

Polyphenol oxidase (PPO) is believed to play a role in plant growth, reproduction, and resistance to pathogens and pests. PPO causes browning of grains in cereals. In this study, genetic mapping of sorghum grain for phenol color reaction (PHR) was performed using a recombinant inbred line population. Only one locus was detected between SSR markers SM06072 and Xtxp176 on chromosome 6. Two linked orthologous genes (Sb06PPO1 and Sb06PPO2) within the mapped region were discovered and cloned. Transformation experiments using Nipponbare (a PHR negative rice cultivar) showed that Sb06PPO1 from LTR108 and two Sb06PPO2 alleles from both varieties could complement Nipponbare, whereas Sb06PPO1 from 654 could not...

BACKROUND: Interactions among invertebrate predators could affect a pest suppression. The hemipteran species Macrolophus pygmaeus (Rambur) and Nesidiocoris tenuis (Reuter) (Hemiptera: Miridae) are natural enemies of several pests in agroecosystems and coexist in tomato crops in Mediterranean countries. By using the multiplicative risk model (MRM) and the substitutive model, the multiple predator effects (MPEs) on prey suppression was calculated when two individuals of the predators foraged at the same densities of the South American tomato pinworm, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), eggs...