scholarly journals Next Generation dsRNA-Based Insect Control: Success So Far and Challenges

2021 ◽  
Vol 12 ◽  
Author(s):  
Rahul B. Nitnavare ◽  
Joorie Bhattacharya ◽  
Satnam Singh ◽  
Amardeep Kour ◽  
Malcolm J. Hawkesford ◽  
...  
Keyword(s):  
Endosomal Escape ◽  
Pest Species ◽  
New Techniques ◽  
Environment Friendly ◽  
Safe Delivery ◽  
Rnai Efficiency ◽  
Important Pest ◽  
Living Organisms ◽  
Underlying Mechanisms ◽  
Interfering Rna

RNA interference (RNAi) is a method of gene silencing where dsRNA is digested into small interfering RNA (siRNA) in the presence of enzymes. These siRNAs then target homologous mRNA sequences aided by the RNA-induced silencing complex (RISC). The mechanism of dsRNA uptake has been well studied and established across many living organisms including insects. In insects, RNAi is a novel and potential tool to develop future pest management means targeting various classes of insects including dipterans, coleopterans, hemipterans, lepidopterans, hymenopterans and isopterans. However, the extent of RNAi in individual class varies due to underlying mechanisms. The present review focuses on three major insect classes viz hemipterans, lepidopterans and coleopterans and the rationale behind this lies in the fact that studies pertaining to RNAi has been extensively performed in these groups. Additionally, these classes harbour major agriculturally important pest species which require due attention. Interestingly, all the three classes exhibit varying levels of RNAi efficiencies with the coleopterans exhibiting maximum response, while hemipterans are relatively inefficient. Lepidopterans on the other hand, show minimum response to RNAi. This has been attributed to many facts and few important being endosomal escape, high activity dsRNA-specific nucleases, and highly alkaline gut environment which renders the dsRNA unstable. Various methods have been established to ensure safe delivery of dsRNA into the biological system of the insect. The most common method for dsRNA administration is supplementing the diet of insects via spraying onto leaves and other commonly eaten parts of the plant. This method is environment-friendly and superior to the hazardous effects of pesticides. Another method involves submergence of root systems in dsRNA solutions and subsequent uptake by the phloem. Additionally, more recent techniques are nanoparticle- and Agrobacterium-mediated delivery systems. However, due to the novelty of these biotechnological methods and recalcitrant nature of certain crops, further optimization is required. This review emphasizes on RNAi developments in agriculturally important insect species and the major hurdles for efficient RNAi in these groups. The review also discusses in detail the development of new techniques to enhance RNAi efficiency using liposomes and nanoparticles, transplastomics, microbial-mediated delivery and chemical methods.

Percussion signals of Lygus rugulipennis Poppius (Heteroptera: Miridae)

2014 ◽  
Vol 9 (5) ◽  
pp. 543-549
Author(s):  
Sándor Koczor ◽  
Andrej Cokl
Keyword(s):  
Dominant Frequency ◽  
Laser Vibrometer ◽  
Pest Species ◽  
Adult Males ◽  
Tarnished Plant Bug ◽  
Lygus Rugulipennis ◽  
Important Pest ◽  
Low Pass ◽  
Males And Females ◽  
Study Laboratory

AbstractThe European tarnished plant bug (Lygus rugulipennis Poppius) is among the most serious pests in the family Miridae, and therefore there is increasing interest in understanding the behaviour of this species. In the present study, laboratory recordings were taken using a laser vibrometer on adult males and females to ascertain whether acoustic signals are involved in intraspecific communication. Recordings were both carried out on plant and loudspeaker membrane substrates. Males and females emitted vibratory signals and the present results indicate that these signals are important during courtship. The basic signal characteristics measured were the dominant frequency, pulse duration, repetition time and number of pulses per group within the signal. Male and female signals did not differ in respect to any of these characteristics. Plant recorded signals were longer because of different mechanical properties of substrates. Additionally, the high frequency components were attenuated due to the low-pass filtering properties of plants. As this is the first study on vibratory communication of the European tarnished plant bug, we believe these findings may contribute considerably to the better understanding of the mating behavior of this important pest species.

scholarly journals Cryptic Diversity Hidden within the Leafminer Genus Liriomyza (Diptera: Agromyzidae)

Genes ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 554 ◽  
Author(s):  
Antonio Carapelli ◽  
Abir Soltani ◽  
Chiara Leo ◽  
Matteo Vitale ◽  
Moez Amri ◽  
...  
Keyword(s):  
Population Genetics ◽  
Species Delimitation ◽  
Decisive Role ◽  
Molecular Data ◽  
Point Of View ◽  
Species Differentiation ◽  
Pest Species ◽  
Human Diet ◽  
Important Pest ◽  
Highly Uniform

Leafminer insects of the genus Liriomyza are small flies whose larvae feed on the internal tissue of some of the most important crop plants for the human diet. Several of these pest species are highly uniform from the morphological point of view, meaning molecular data represents the only reliable taxonomic tool useful to define cryptic boundaries. In this study, both mitochondrial and nuclear molecular markers have been applied to investigate the population genetics of some Tunisian populations of the polyphagous species Liriomyza cicerina, one of the most important pest of chickpea cultivars in the whole Mediterranean region. Molecular data have been collected on larvae isolated from chickpea, faba bean, and lentil leaves, and used for population genetics, phylogenetics, and species delimitation analyses. Results point toward high differentiation levels between specimens collected on the three different legume crops, which, according to the species delimitation methods, are also sufficient to define incipient species differentiation and cryptic species occurrence, apparently tied up with host choice. Genetic data have also been applied for a phylogenetic comparison among Liriomyza species, further confirming their decisive role in the systematic studies of the genus.

scholarly journals An Inactivation Switch Enables Rhythms in a Neurospora Clock Model

2019 ◽  
Vol 20 (12) ◽  
pp. 2985 ◽  
Author(s):  
Abhishek Upadhyay ◽  
Michael Brunner ◽  
Hanspeter Herzel
Keyword(s):  
Feedback Loop ◽  
Design Principle ◽  
Temporal Dynamics ◽  
Model Organism ◽  
Transcription Activator ◽  
White Collar Complex ◽  
Living Organisms ◽  
Underlying Mechanisms ◽  
Molecular Components ◽  
Novel Model

Autonomous endogenous time-keeping is ubiquitous across many living organisms, known as the circadian clock when it has a period of about 24 h. Interestingly, the fundamental design principle with a network of interconnected negative and positive feedback loops is conserved through evolution, although the molecular components differ. Filamentous fungus Neurospora crassa is a well-established chrono-genetics model organism to investigate the underlying mechanisms. The core negative feedback loop of the clock of Neurospora is composed of the transcription activator White Collar Complex (WCC) (heterodimer of WC1 and WC2) and the inhibitory element called FFC complex, which is made of FRQ (Frequency protein), FRH (Frequency interacting RNA Helicase) and CK1a (Casein kinase 1a). While exploring their temporal dynamics, we investigate how limit cycle oscillations arise and how molecular switches support self-sustained rhythms. We develop a mathematical model of 10 variables with 26 parameters to understand the interactions and feedback among WC1 and FFC elements in nuclear and cytoplasmic compartments. We performed control and bifurcation analysis to show that our novel model produces robust oscillations with a wild-type period of 22.5 h. Our model reveals a switch between WC1-induced transcription and FFC-assisted inactivation of WC1. Using the new model, we also study the possible mechanisms of glucose compensation. A fairly simple model with just three nonlinearities helps to elucidate clock dynamics, revealing a mechanism of rhythms’ production. The model can further be utilized to study entrainment and temperature compensation.

scholarly journals Punicalagin protects H9c2 cardiomyocytes from doxorubicin-induced toxicity through activation of Nrf2/HO-1 signaling

2019 ◽  
Vol 39 (5) ◽  
Author(s):  
Mingfang Ye ◽  
Linlin Zhang ◽  
Yuanming Yan ◽  
Huizhong Lin
Keyword(s):  
Wide Spectrum ◽  
Critical Role ◽  
Antitumor Agent ◽  
Cytochrome C Release ◽  
Beneficial Effects ◽  
H9c2 Cardiomyocytes ◽  
Underlying Mechanisms ◽  
Interfering Rna

Abstract Doxorubicin (DOX) is a wide-spectrum antitumor agent, but its clinical application is largely limited by its cardiotoxicity. Therefore, identification of effective agents against DOX-induced cardiotoxicity is of critical importance. The present study aimed to determine the beneficial role of punicalagin (PUN), a polyphenol isolated from pomegranate, in DOX-induced cardiotoxicity in vitro and explored the underlying mechanisms. H9c2 cardiomyocytes were pretreated with different concentrations (50, 100 and 200 μM) of PUN prior to DOX exposure. The results showed that PUN pretreatment significantly increased cell viability, inhibited lactate dehydrogenase (LDH) release and suppressed cell apoptosis induced by DOX. Additionally, PUN pretreatment attenuated the loss of mitochondrial membrane potential and cytochrome c release. Besides, PUN further enhanced the expression of nuclear Nrf2 and HO-1 in DOX-treated H9c2 cells, and the aforementioned beneficial effects of PUN were partially abolished by small interfering RNA (siRNA)-mediated Nrf2 knockdown. Hence, our findings clearly revealed that PUN might be a promising agent for alleviating the cardiotoxicity of DOX, and Nrf2/HO-1 signaling might serve a critical role during this process.

scholarly journals Generalism in Nature…The Great Misnomer: Aphids and Wasp Parasitoids as Examples

Insects ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 314 ◽  
Author(s):  
Hugh D. Loxdale ◽  
Adalbert Balog ◽  
Jeffrey A. Harvey
Keyword(s):  
Ecological Niche ◽  
Large Degree ◽  
Parasitoid Wasps ◽  
Pest Species ◽  
Entry And Exit ◽  
Relaxed Selection ◽  
Dietary Breadth ◽  
Trade Offs ◽  
Enemy Free Space ◽  
Living Organisms

In the present article we discuss why, in our view, the term ‘generalism’ to define the dietary breadth of a species is a misnomer and should be revised by entomologists/ecologists with the more exact title relating to the animal in question’s level of phagy—mono-, oligo, or polyphagy. We discard generalism as a concept because of the indisputable fact that all living organisms fill a unique ecological niche, and that entry and exit from such niches are the acknowledged routes and mechanisms driving ecological divergence and ultimately speciation. The term specialist is probably still useful and we support its continuing usage simply because all species and lower levels of evolutionary diverge are indeed specialists to a large degree. Using aphids and parasitoid wasps as examples, we provide evidence from the literature that even some apparently highly polyphagous agricultural aphid pest species and their wasp parasitoids are probably not as polyphagous as formerly assumed. We suggest that the shifting of plant hosts by herbivorous insects like aphids, whilst having positive benefits in reducing competition, and reducing antagonists by moving the target organism into ‘enemy free space’, produces trade-offs in survival, involving relaxed selection in the case of the manicured agro-ecosystem.

Eva1a ameliorates atherosclerosis by promoting re-endothelialization of injured arteries via Rac1/Cdc42/Arpc1b

2020 ◽  
Author(s):  
Jingxuan Li ◽  
Yingyu Chen ◽  
Jianing Gao ◽  
Yue Chen ◽  
Changping Zhou ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Cell Counting ◽  
Human Aorta ◽  
Atherosclerotic Lesions ◽  
Rna Transfection ◽  
Promising Therapeutic Target ◽  
Carotid Artery Injuries ◽  
Underlying Mechanisms ◽  
Interfering Rna ◽  
Novel Protein

Abstract Aims Eva-1 homologue 1 (Eva1a) is a novel protein involved in the regulation of cardiac remodelling and plaque stability, but little is known about its role in re-endothelialization and the development of atherosclerosis (AS). Thus, in the present study, we aimed to elucidate the function of Eva1a in re-endothelialization and AS. Methods and results Wire injuries of carotid and femoral arteries were established in Eva1a−/− mice. Eva1a-deficient mice were crossed with apolipoprotein E−/− (ApoE−/−) mice to evaluate AS development and re-endothelialization of carotid artery injuries. Denudation of the carotid artery at 3, 5, and 7 days was significantly aggravated in Eva1a−/− mice. The neointima of the femoral artery at 14 and 28 days was consequently exacerbated in Eva1a−/− mice. The area of atherosclerotic lesions was increased in Eva1a−/−ApoE−/− mice. To explore the underlying mechanisms, we performed transwell, scratch migration, cell counting kit-8, and bromodeoxyuridine assays using cultured human aorta endothelial cells (HAECs), which demonstrated that EVA1A promoted HAEC migration and proliferation. Proteomics revealed that the level of actin-related protein 2/3 complex subunit 1B (Arpc1b) was decreased, while Eva1a expression was absent. Arpc1b was found to be a downstream molecule of EVA1A by small interfering RNA transfection assay. Activation of Rac1 and Cdc42 GTPases was also regulated by EVA1A. Conclusion This study provides insights into anti-atherogenesis effects of Eva1a by promoting endothelium repair. Thus, Eva1a is a promising therapeutic target for AS.

Important pest species of the Spodoptera complex: Biology, thermal requirements and ecological zoning

2021 ◽  
Author(s):  
José Roberto Postali Parra ◽  
Aloisio Coelho ◽  
Johanna Bajonero Cuervo-Rugno ◽  
Adriano Gomes Garcia ◽  
Rafael de Andrade Moral ◽  
...  
Keyword(s):  
Pest Species ◽  
Thermal Requirements ◽  
Important Pest

THE EGG AND OVIPOSITION SITE OF DERAEOCORIS NEBULOSUS (HEMIPTERA: MIRIDAE) ON APPLE TREES

1980 ◽  
Vol 112 (5) ◽  
pp. 527-528 ◽  
Author(s):  
J. P. McCaffrey ◽  
R. L. Horsburgh
Keyword(s):  
Panonychus Ulmi ◽  
Oviposition Site ◽  
Pest Species ◽  
Apple Orchards ◽  
Apple Trees ◽  
European Red Mite ◽  
Important Pest ◽  
Ornamental Trees ◽  
Trees And Shrubs ◽  
Oviposition Sites

The predaceous mirid Deraeocoris nebulosus (Uhler) is found on more than 50 species of ornamental trees and shrubs where it feeds on several important pest species (Wheeler et al. 1975). It is a common mite and aphid predator in commercial apple orchards in Virginia (Parrella et al. 1978). Wheeler et al. (1975) described the nymphal stages and biology, but made no mention of the egg or oviposition site. We describe the egg and oviposition site which we discovered while studying various predators of the European red mite, Panonychus ulmi (Koch), in Virginia apple orchards. Eggs and oviposition sites of other predaceous mirids associated with apple have been described (Kullenberg 1942; Collyer 1952, 1953; Sanford 1964; Horsburgh and Asquith 1968, 1970).

scholarly journals HAMA PENTING TANAMAN UBI JALAR (Ipomea batatas L.(Lamb)) DI KABUPATEN MINAHASA, MINAHASA UTARA, DAN KOTA TOMOHON

EUGENIA ◽  
2011 ◽  
Vol 17 (2) ◽  
Author(s):  
Odi R. Pinontoan ◽  
Maxi Lengkong ◽  
Henny V.G. Makal
Keyword(s):  
Sweet Potato ◽  
Field Research ◽  
Laboratory Research ◽  
Survey Method ◽  
Pest Species ◽  
Sweet Potatoes ◽  
Potato Plants ◽  
Cylas Formicarius ◽  
Ipomea Batatas ◽  
Important Pest

ABSTRACT The research aimed to identify important pests which attack sweet potato in the field. Field and laboratory research were conducted. The field research was carried out in sweet potato cropping areas in Minahasa Regency, North Minahasa regency and  Tomohon. The laboratory research was conducted in plant pests and disease laboratory, Faculty of Agriculture Sam Ratulangi University Manado to idedntify the important pest species which were found on sweet potato plants. The duration of the study was four months starting from December 2010 until March 2011. Survey method was applied with purposive random sampling.  The research was used 4 period of plant growth namely 1 month, 2 months,3 months, and 4-5 months after planting. The result showed that there were five orders identified, attacking sweet potato since the age of 1-4 months in Minahasa regency, Tomohon and North Minahasa regency. The five orders were Orthoptera, Hemiptera, Homoptera, Lepidoptera, and Coleoptera. The damage on the leaves were caused by pests coreidae, Cicadelidae, Spodoptera sp (Noctuidae), Valanga sp (Acrididae), and Oxya sp. (Acrididae), whereas on the stem was Omphisa sp (Pyralidae). Damage on the tuber was caused by Gryllotalpa sp (Gryllotalpidae), Cylas formicarius (Curculionidae) and Oryctes sp (Dynastidae). Key words : Important Pest Plant Sweet Potatoes, Ipomea batatas L.

scholarly journals Nine Mitochondrial Genomes of the Pyraloidea and Their Phylogenetic Implications (Lepidoptera: Pyraloidea)

Insects ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1039
Author(s):  
Xiaomeng Liu ◽  
Mujie Qi ◽  
Haizhen Xu ◽  
Zhipeng Wu ◽  
Lizong Hu ◽  
...  
Keyword(s):  
Crop Production ◽  
Phylogenetic Analyses ◽  
Molecular Data ◽  
Phylogenetic Position ◽  
Morphological Evidence ◽  
Pest Species ◽  
Great Loss ◽  
Phylogenetic Implications ◽  
Important Pest ◽  
High Level

The Pyraloidea is one of the species-rich superfamilies of Lepidoptera and contains numerous economically important pest species that cause great loss in crop production. Here, we sequenced and annotated nine complete mitogenomes for Pyraloidea, and further performed various phylogenetic analyses, to improve our understanding of mitogenomic evolution and phylogeny of this superfamily. The nine mitogenomes were circular, double-stranded molecules, with the lengths ranging from 15,214 bp to 15,422 bp, which are comparable to other reported pyraloid mitogenomes in size. Gene content and arrangement were highly conserved and are typical of Lepidoptera. Based on the hitherto most extensive mitogenomic sampling, our various resulting trees showed generally congruent topologies among pyraloid subfamilies, which are almost in accordance with previous multilocus studies, indicating the suitability of mitogenomes in inferring high-level relationships of Pyraloidea. However, nodes linking subfamilies in the “non-PS clade” were not completely resolved in terms of unstable topologies or low supports, and future investigations are needed with increased taxon sampling and molecular data. Unexpectedly, Orybina Snellen, represented in a molecular phylogenetic investigation for the first time, was robustly placed as basal to the remaining Pyralidae taxa across our analyses, rather than nested in Pyralinae of Pyralidae as morphologically defined. This novel finding highlights the need to reevaluate Orybina monophyly and its phylogenetic position by incorporating additional molecular and morphological evidence.

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