Influence of the surrounding landscape on crop colonization by a polyphagous insect pest

2013 ◽  
Vol 149 (1) ◽  
pp. 11-21 ◽  
Author(s):  
Frances S. Sivakoff ◽  
Jay A. Rosenheim ◽  
Pierre Dutilleul ◽  
Yves Carrière
Keyword(s):  
Insect Pest ◽  
Surrounding Landscape ◽  
Polyphagous Insect

Effects of insecticides chlorpyrifos, emamectin benzoate and fipronil on Spodoptera litura might be mediated by OBPs and CSPs

2017 ◽  
Vol 108 (5) ◽  
pp. 658-666 ◽  
Author(s):  
X. Lin ◽  
Y. Jiang ◽  
L. Zhang ◽  
Y. Cai
Keyword(s):  
Spodoptera Litura ◽  
Quantitative Polymerase Chain Reaction ◽  
Insect Pest ◽  
Survival Rates ◽  
Gene Families ◽  
Cross Resistance ◽  
Emamectin Benzoate ◽  
Insecticide Exposure ◽  
Polyphagous Insect ◽  
Related Proteins

AbstractSpodoptera litura is a widespread polyphagous insect pest that can develop resistance and cross-resistance to insecticides, making it difficult to control. Insecticide exposure has previously been linked with induction of specific olfactory-related proteins, including some chemosensory proteins (CSPs) and odorant-binding proteins (OPBs), which may disrupt detection of environmental factors and reduce fitness. However, functional evidence supporting insecticide and OBPs/CSPs mediation remains unknown. Here we fed male S. litura moths with sucrose water containing one of three insecticides, chlorpyrifos, emamectin benzoate or fipronil, and used real-time quantitative polymerase chain reaction and RNAi to investigate OBPs and CSPs expression and their correlations with survival. Chlorpyrifos and emamectin benzoate increased expression of 78% of OBPs, plus 63 and 56% of CSP genes, respectively, indicating a major impact on these gene families. RNAi knockdown of SlituCSP18, followed by feeding with chlorpyrifos or fipronil, decreased survival rates of male moths significantly compared with controls. Survival rate also decreased significantly with the downregulation of SlituOBP9 followed by feeding with chlorpyrifos. Thus, although these three insecticides had different effects on OBP and CSP gene expression, we hypothesize that SlituOBPs and SlituCSPs might mediate their effects by increasing their expression levels to improve survival. Moreover, the differential response of S. litura male moths to the three insecticides indicated the potential specificity of chlorpyrifos affect SlituCSP18 and SlituOBP9 expression.

scholarly journals RNA interference-mediated tolerance to whitefly (Bemisia tabaci) in genetically engineered tomato

2021 ◽  
Author(s):  
Carolina Senhorinho Ramalho Pizetta ◽  
William Rafael Ribeiro ◽  
Amanda Lopes Ferreira ◽  
Matheus da Costa Moura ◽  
Kenny Bonfim ◽  
...  
Keyword(s):  
Rna Interference ◽  
Transgenic Plants ◽  
Bemisia Tabaci ◽  
Insect Pest ◽  
Genetically Engineered ◽  
Horticultural Crops ◽  
Transgenic Tomato Plants ◽  
Atpase Gene ◽  
Transgenic Lines ◽  
Polyphagous Insect

Abstract Whitefly (Bemisia tabaci) is a polyphagous insect that causes huge damage in several horticultural crops, including tomato, by sucking nutrients from the phloem and transmitting viruses. Whiteflies are particularly difficult to manage and the use of chemicals remains the common practice, which causes the development of insecticidal resistance. Thus, there is considerable interest in the introduction of whitefly resistance by classical and molecular breeding. Here, we explored the concept of using an RNA interference construct to silence a v-ATPase gene in whiteflies interacting with transgenic tomato plants that express siRNA molecules corresponding to a fragment from the B. tabaci vATPase. PCR analyses revealed the presence of both ΔATPase and nptII transgenes in all transgenic lines. siRNA expressing lines were challenged against whitefly and revealed a mortality rate of 57.1% in transgenic line 4.4.1, while in the control the mortality was 7.6%. Mortality of 2nd instar nymphs was higher on the transgenic plants and the development of 3rd instar nymphs was slightly longer than on the control plants. Although the attraction of insects was not significantly different between treatments, the number of eggs laid by the insects on the transgenic plants was significantly lower, compared to the controls. RT-qPCR revealed a decreased expression level of endogenous v-ATPase gene in whiteflies feeding on transgenic plants. No unexpected effect was observed on the non-target insects Myzus persicae or Tuta absoluta. Results presented here may form the foundation for the generation of elite tomato varieties resistant to whitefly, a devastating insect pest.

scholarly journals Seasonal Abundance and Spatial Pattern of Distribution of Liriomyza trifolii (Diptera: Agromyzidae) and Its Parasitoid on Bean and Squash in South Florida

2021 ◽  
Author(s):  
Shashan Devkota ◽  
Dakshina R. Seal
Keyword(s):  
Insect Pest ◽  
Ornamental Plants ◽  
South Florida ◽  
Seasonal Abundance ◽  
Liriomyza Trifolii ◽  
Snap Bean ◽  
Wide Range ◽  
The Mean ◽  
Serpentine Leafminer ◽  
Polyphagous Insect

ABSTRACTAmerican serpentine leafminer, Liriomyza trifolii, is a polyphagous insect pest that feeds on a wide range of vegetable and ornamental plants around the world. To develop an effective IPM program, information on the seasonal field distribution and population dynamics of leafminer and its parasitoids is very important. Therefore, seasonal abundances and spatial distributions of, L. trifolii on snap bean and squash were studied during four crop growing periods between 2013 to 2015 in Homestead, Florida. The mean numbers of mines, larvae, pupae, emerged adults, and parasitoids on snap bean were highest at 2 weeks after planting during all four growing periods. Whereas, the mean numbers of mines, larvae, pupae, emerged adults, and parasitoids on squash were highest at 3 weeks after planting during all four growing periods. L. trifolii distributions tended to be aggregated (1 < b/β) on snap bean at 2 weeks after planting during all four growing periods but had uniform (1 > b/β) distributions on squash at 2 weeks after planting during all four growing periods. Similar results were seen on the distribution of leafminer parasitoids on both bean and squash.

scholarly journals Transcriptome analysis of developmental stages of cocoa pod borer, Conopomorpha cramerella: A polyphagous insect pest of economic importance in Southeast Asia.

2021 ◽  
Author(s):  
Chia Lock Tan ◽  
Rosmin Kasran ◽  
Wei Wei Lee ◽  
Wai Mun Leong
Keyword(s):  
Southeast Asia ◽  
Developmental Stages ◽  
Transcriptome Assembly ◽  
Insect Pest ◽  
Homology Search ◽  
General Function ◽  
Protein Coding ◽  
Pod Borer ◽  
Three Stages ◽  
Polyphagous Insect

The cocoa pod borer, Conopomorpha cramerella (Snellen) is a serious pest in cocoa plantations in Southeast Asia.  It causes significant losses in the crop.  Unfortunately, genetic resources for this insect is extremely scarce.  To improve these resources, we sequenced the transcriptome of C. cramerella representing the three stages of development, larva, pupa and adult moth using Illumina NovaSeq6000.  Transcriptome assembly was performed by Trinity for all the samples.  A total number of 147,356,088 high quality reads were obtained.  Of these, 285,882 contigs were assembled.  The mean contig size was 374 bp.  Protein coding sequence (CDS) was extracted from the reconstructed transcripts by TransDecoder.  Subsequently, BlastX and InterProScan were applied for homology search to make a prediction of the function of CDS in unigene.  Additionally, we identified a number of genes that are involved in reproduction and development such as genes involved in general function processes in the insect.  Genes found to be involved in reproduction such as porin, dsx, bol and fruitless were associated with sex determination, spermatogenesis and pheromone binding.  Furthermore, transcriptome changes during development were analysed.  There were 2,843 differentially expressed genes (DEG) detected between the larva and pupa samples.  A total of 2,861 DEG were detected between adult and larva stage whereas between adult and pupa stage, 1,953 DEG were found.  In conclusion, the transcriptomes could be a valuable genetic resource for identification of genes in C. cramerella and the study will provide putative targets for RNAi pest control.

Spatial and Temporal Dynamics of the Native Banana-Spotting Bug, Amblypelta lutescens lutescens (Hemiptera: Coreidae), in Avocado Crops in North Queensland, Australia

2019 ◽  
Vol 112 (4) ◽  
pp. 1812-1820
Author(s):  
Karel R Lindsay ◽  
Myron P Zalucki ◽  
Ian R Newton ◽  
Michael J Furlong
Keyword(s):  
Riparian Vegetation ◽  
Temporal Dynamics ◽  
Spatial Clustering ◽  
Insect Pest ◽  
Persea Americana ◽  
Adult Males ◽  
Horticultural Crops ◽  
Spatial And Temporal Dynamics ◽  
Polyphagous Insect ◽  
Main Components

Abstract The native banana-spotting bug, Amblypelta lutescens lutescens Distant, is a major polyphagous insect pest of many tropical and subtropical horticultural crops in Australia, including high-valued commodities such as avocado (Persea americana Mill. (Laurales: lauraceae)). The cryptic nature of A. l. lutescens makes it difficult to sample, and much about its ecology and behavior remains poorly understood. A lure based on the main components of the semiochemicals emitted by male A. l. lutescens, which is attractive to adult males, adult females, and nymphs, has been developed and incorporated into a trap, facilitating sampling of A. l. lutescens in the field. A 2-yr study investigated the spatial and temporal dynamics of the pest in two conventionally managed avocado (cv. Shepard) orchards using a grid (36 m × 36 m) of traps across each. In each year of the study, higher numbers of A. l. lutescens were recorded from October to June. In one field, spatial clustering of adults was detected in close proximity to an adjacent lime [Citrus aurantiifolia (Christm.) (Rutales: rutaceae) Swingle] crop that was not managed with insecticides during the study. Spatial clustering of nymphs was detected adjacent to native riparian vegetation in the other field. The results suggest that source populations of A. l. lutescens could originate from neighboring crops that host A. l. lutescens and from riparian vegetation. Focused sampling of trees at the interface with these vegetation types could lead to early pest detection, timely suppression, and therefore improved pest management.

scholarly journals Genome Sequence of Acinetobacter sp. Strain HA, Isolated from the Gut of the Polyphagous Insect Pest Helicoverpa armigera

2012 ◽  
Vol 194 (18) ◽  
pp. 5156-5156 ◽  
Author(s):  
Jaya Malhotra ◽  
Ankita Dua ◽  
Anjali Saxena ◽  
Naseer Sangwan ◽  
Udita Mukherjee ◽  
...  
Keyword(s):  
Genome Sequence ◽  
Helicoverpa Armigera ◽  
Insect Pest ◽  
Draft Genome ◽  
Instar Larva ◽  
Draft Genome Sequence ◽  
Coding Sequences ◽  
Content Type ◽  
Helicoverpa Armígera ◽  
Polyphagous Insect

ABSTRACTIn this study,Acinetobactersp. strain HA was isolated from the midgut of a fifth-instar larva ofHelicoverpa armigera. Here, we report the draft genome sequence (3,125,085 bp) of this strain that consists of 102 contigs, 2,911 predicted coding sequences, and a G+C content of 41%.

scholarly journals Toxicity of green silver nanoparticles of plant extracts against citrus mealybug Planococcus citri

2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Muhammad Safian Bajwa ◽  
Muhammad Tariq ◽  
Asim Gulzar ◽  
Hassan Saeed ◽  
Zia-ur-Rehman Mashwani
Keyword(s):  
Silver Nanoparticles ◽  
Plant Extracts ◽  
Direct Relationship ◽  
Insect Pest ◽  
Exposure Period ◽  
Planococcus Citri ◽  
Citrus Mealybug ◽  
Horticultural Crops ◽  
Polyphagous Insect ◽  
Eucalyptus Plant

Planococcus citri is an economically important polyphagous insect pest and is a serious threat to horticultural crops especially mango and citrus. It is mainly controlled by synthetic insecticides which have deleterious effects on humans, livestock and environment. To dispense with the detrimental consequences of insecticides, plant extracts and their silver nanoparticles can be potential alternatives. The present study reports the effectiveness of four plant extracts and their silver based nanoparticles against P. citri. All the plant extracts and their silver nanoparticles caused mortalities of 2nd and 3rd instars of P. citri at all concentrations and exposure durations. The ginger extracts and their silver nanoparticles caused maximum mortality of 2nd and 3rd instars of P. citri (94 and 90% respectively) at the highest concentration after 72 hours followed by neem extracts and their silver nanoparticles. Similarly, the mortalities caused by garlic silver nanoparticles followed the similar pattern. Eucalyptus plant extracts and their silver nanoparticles were found to be the lease effective. It was also observed that with an increase in concentration and exposure period, the mortality also increased showing a direct relationship. Ginger plant extract and their silver nanoparticles gave the best results and lowest LC50 values by a large margin. Neem extracts ranked second followed by garlic and eucalyptus and gave significantly poor results as compared to the first two plants. The required concentration for killing 50% of the nymphal population was observed to decrease with the passage of time.

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