scholarly journals Genome and transcriptome analysis of the beet armyworm Spodoptera exigua reveals targets for pest control

2021 ◽  
Author(s):  
Sabrina Simon ◽  
Thijmen Breeschoten ◽  
Hans J Jansen ◽  
Ron P Dirks ◽  
M. Eric Schranz ◽  
...  

Background: The genus Spodoptera (Lepidoptera: Noctuidae) includes some of the most infamous insect pests of cultivated plants including Spodoptera frugiperda, Spodoptera litura and Spodoptera exigua. To effectively develop targeted pest control strategies for diverse Spodoptera species, genomic resources are highly desired. To this aim, we provide the genome assembly and developmental transcriptome comprising all major life stages of S. exigua, the beet armyworm. Spodoptera exigua is a polyphagous herbivore that can feed from > 130 host plants including several economically important crops. Results: The 419 Mb beet armyworm genome was sequenced from a female S. exigua pupa. Using a hybrid genome sequencing approach (Nanopore long read data and Illumina short read), a high-quality genome assembly was achieved (N50=1.1 Mb). An official gene set (OGS, 18,477 transcripts) was generated by automatic annotation and by using transcriptomic RNA-seq data sets of 18 S. exigua samples as supporting evidence. In-depth analyses of developmental stage-specific expression in combination with gene tree analyses of identified homologous genes across Lepidoptera genomes revealed potential Spodoptera-specific genes of interest such as mg7 and REPAT46 upregulated during 1st and 3rd instar larval stages for targeted pest-outbreak management. Conclusions: The beet armyworm genome sequence and developmental transcriptome covering all major developmental stages provides critical insights into the biology of this devastating polyphagous insect pest species with a worldwide distribution. In addition, comparative genomic analyses across Lepidoptera significantly advance our knowledge to further control other invasive Spodoptera species and reveals potential lineage-specific target genes for pest control strategies.

Author(s):  
Sabrina Simon ◽  
Thijmen Breeschoten ◽  
Hans J Jansen ◽  
Ron P Dirks ◽  
M Eric Schranz ◽  
...  

Abstract The genus Spodoptera (Lepidoptera: Noctuidae) includes some of the most infamous insect pests of cultivated plants including Spodoptera frugiperda, Spodoptera litura and Spodoptera exigua. To effectively develop targeted pest control strategies for diverse Spodoptera species, genomic resources are highly desired. To this aim, we provide the genome assembly and developmental transcriptome comprising all major life stages of S. exigua, the beet armyworm. Spodoptera exigua is a polyphagous herbivore that can feed on > 130 host plants, including several economically important crops. The 419 Mb beet armyworm genome was sequenced from a female S. exigua pupa. Using a hybrid genome sequencing approach (Nanopore long read data and Illumina short read), a high-quality genome assembly was achieved (N50=1.1 Mb). An official gene set (OGS, 18,477 transcripts) was generated by automatic annotation and by using transcriptomic RNA-seq data sets of 18 S. exigua samples as supporting evidence. In-depth analyses of developmental stage-specific expression combined with gene tree analyses of identified homologous genes across Lepidoptera genomes revealed four potential genes of interest (three of them Spodoptera-specific) upregulated during 1st and 3rd instar larval stages for targeted pest-outbreak management. The beet armyworm genome sequence and developmental transcriptome covering all major developmental stages provide critical insights into the biology of this devastating polyphagous insect pest species worldwide. In addition, comparative genomic analyses across Lepidoptera significantly advance our knowledge to further control other invasive Spodoptera species and reveals potential lineage-specific target genes for pest control strategies.


Author(s):  
Marco Infusino ◽  
Nino Iannotta ◽  
Stefano Scalercio

One of the key-points in sustainable agriculture is to minimize the amount of pesticides inputs in agro-ecosystems increasing selectivity of active agents on target pests mainly. According to this perspective, control strategies utilising baits receive a growing interest. a spinosad-poisoned sugar-based bait, the so called GF-120 bait, utilised against diptera Tephritidae, recently appeared on the market. The toxicity of spinosad for non-target insects is demonstrated by several authors. However, the amount of pesticide applied is strongly reduced by using it with an attractive food-bait, even if field evidences on the selective attraction of this bait are missing. The aim of this paper is to evaluate the selectivity of GF-120 bait toward target and non-target insects under field conditions, focussing our attention on pollinators. Field trials were performed in a 20 years old olive orchard, where 12 baited and 12 unbaited traps were positioned for insect monitoring. The abundance of the most common orders of insects and target pest species Bactrocera oleae and Ceratitis capitata has been assessed. The main finding of this research is that many pollinators are not attracted by the bait, while target and non-target diptera are significantly attracted by the bait with the exception of Muscidae. The attraction toward a part of non-target diptera should be better explored in order to avoid negative impact on beneficial and non-target species. The need of pest control strategies safer for the environment and the wild populations of non-target organisms seems to be satisfied by the use of this bait.


Author(s):  
Feng Zhang ◽  
Jianpeng Zhang ◽  
Yihua Yang ◽  
Yidong Wu

AbstractBackgroundThe beet armyworm, Spodoptera exigua (Hübner), is a worldwide, polyphagous agricultural pest feeding on vegetable, field, and flower crops. However, the lack of genome information on this insect severely limits our understanding of its rapid adaptation and hampers the development of efficient pest management strategies.FindingsWe report a chromosome-level genome assembly using single-molecule real-time PacBio sequencing and Hi-C data. The final genome assembly was 446.80 Mb with a scaffold N50 of 14.36 Mb, and captured 97.9% complete arthropod Benchmarking Universal Single-Copy Orthologs (BUSCO, n=1,658). A total of 367 contigs were anchored to 32 pseudo-chromosomes, covering 96.18% (429.74 Mb) of the total genome length. We predicted 17,727 protein-coding genes, of which 81.60% were supported by transcriptome evidence and 96.47% matched UniProt protein records. We also identified 867,102 (147.97 Mb/33.12%) repetitive elements and 1,609 noncoding RNAs. Synteny inference indicated a conserved collinearity between three lepidopteran species. Gene family evolution and function enrichment analyses showed the significant expansions in families related to development, dietary, detoxification and chemosensory system, indicating these families may play a role in host plant specialization and niche adaptation.ConclusionsWe have generated a high-quality chromosomal-level genome that could provide a valuable resource for a better understanding and management of the beet armyworm.


2008 ◽  
Vol 98 (6) ◽  
pp. 613-619 ◽  
Author(s):  
X. Chen ◽  
H. Tian ◽  
L. Zou ◽  
B. Tang ◽  
J. Hu ◽  
...  

AbstractRNA interference (RNAi) is a powerful tool for rapidly analyzing gene functions. However, little is known about the possible use of dsRNA/siRNA as a pest control method. Here, we demonstrate that dsRNA/siRNA can induce the silence of chitin synthase gene A (CHSA), which is an important gene for the growth and development of cuticles and trachea in beet armyworm, Spodoptera exigua. Based on the in vitro RNAi experiments in an insect cell line (Trichoplusia ni High 5), in vivo RNAi was performed by injecting synthesized dsRNA/siRNA into the 4th instar larvae of S. exigua. Significantly lower levels of CHSA transcripts were detected. In addition, the cuticle of these insects was disordered and the epithelial walls of larval trachea did not expand uniformly in injected individuals. Moreover, Injections significantly increased abnormalities relative to control larvae. These results highlighted the possibility of dsRNA/siRNA for gene function studies in lepidopteran insects and future pest control.


Insects ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 415 ◽  
Author(s):  
Olivier Christiaens ◽  
Jinzhi Niu ◽  
Clauvis Nji Tizi Taning

In this editorial for the Special Issue on ‘RNAi in insect pest control’, three important applications of RNA interference (RNAi) in insects are briefly discussed and linked to the different studies published in this Special Issue. The discovery of the RNAi mechanism revolutionized entomological research, as it presented researchers with a tool to knock down genes, which is easily applicable in a wide range of insect species. Furthermore, RNAi also provides crop protection with a novel and promising pest control mode-of-action. The sequence-dependent nature allows RNAi-based control strategies to be highly species selective and the active molecule, a natural biological molecule known as double-stranded RNA (dsRNA), has a short environmental persistence. However, more research is needed to investigate different cellular and physiological barriers, such as cellular uptake and dsRNA degradation in the digestive system in insects, in order to provide efficient control methods against a wide range of insect pest species. Finally, the RNAi pathway is an important part of the innate antiviral immune defence of insects, and could even lead to applications targeting viruses in beneficial insects such as honeybees in the future.


Sociobiology ◽  
2018 ◽  
Vol 65 (2) ◽  
pp. 320 ◽  
Author(s):  
Bruno Corrêa Barbosa ◽  
Newton José de Jesus Silva ◽  
José Cola Zanuncio ◽  
Fábio Prezoto

Predation of Lepidoptera caterpillars - including agricultural pest species - is one of the main ways through which social wasps gather proteinaceous resources. The presence of social wasps was sampled through active search and bait traps through a sugarcane culture cycle, totaling 12 months. Our aim was to record the presence of these insects during the sugarcane development cycle in order to obtain data to support alternative pest control strategies. A total of 1091 individuals in seven genera and 20 species of social wasps were collected, including the swarm-founding Agelaia vicina and Polybia sericea (Hymenoptera: Vespidae). Social wasp richness and abundance were not correlated with climatic variables (temperature, humidity and precipitation). However, richness was negatively correlated to the sugarcane plants’ height (r= -0.4360, p= 0.05). The presence of social wasps during the plant’s cycle shows their potential as predators in sugarcane culture pest management.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Guilherme B. Dias ◽  
Musaad A. Altammami ◽  
Hamadttu A. F. El-Shafie ◽  
Fahad M. Alhoshani ◽  
Mohamed B. Al-Fageeh ◽  
...  

AbstractThe red palm weevil Rhynchophorus ferrugineus (Coleoptera: Curculionidae) is an economically-important invasive species that attacks multiple species of palm trees around the world. A better understanding of gene content and function in R. ferrugineus has the potential to inform pest control strategies and thereby mitigate economic and biodiversity losses caused by this species. Using 10x Genomics linked-read sequencing, we produced a haplotype-resolved diploid genome assembly for R. ferrugineus from a single heterozygous individual with modest sequencing coverage ($$\sim$$ ∼ 62x). Benchmarking against conserved single-copy Arthropod orthologs suggests both pseudo-haplotypes in our R. ferrugineus genome assembly are highly complete with respect to gene content, and do not suffer from haplotype-induced duplication artifacts present in a recently published hybrid assembly for this species. Annotation of the larger pseudo-haplotype in our assembly provides evidence for 23,413 protein-coding loci in R. ferrugineus, including over 13,000 predicted proteins annotated with Gene Ontology terms and over 6000 loci independently supported by high-quality Iso-Seq transcriptomic data. Our assembly also includes 95% of R. ferrugineus chemosensory, detoxification and neuropeptide-related transcripts identified previously using RNA-seq transcriptomic data, and provides a platform for the molecular analysis of these and other functionally-relevant genes that can help guide management of this widespread insect pest.


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