scholarly journals De Novo Transcriptome Identifies Olfactory Genes in Diachasmimorpha longicaudata (Ashmead)

Genes ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 144 ◽  
Author(s):  
Liangde Tang ◽  
Jimin Liu ◽  
Lihui Liu ◽  
Yonghao Yu ◽  
Haiyan Zhao ◽  
...  
Keyword(s):  
De Novo ◽  
Biological Control Agent ◽  
Odorant Receptor ◽  
Parasitoid Wasp ◽  
Control Agent ◽  
Fruit Flies ◽  
Ionotropic Receptor ◽  
Protein Levels ◽  
Diachasmimorpha Longicaudata ◽  
Sensory Neuron Membrane Protein

Diachasmimoorpha longicaudata (Ashmead, D. longicaudata) (Hymenoptera: Braconidae) is a solitary species of parasitoid wasp and widely used in integrated pest management (IPM) programs as a biological control agent in order to suppress tephritid fruit flies of economic importance. Although many studies have investigated the behaviors in the detection of their hosts, little is known of the molecular information of their chemosensory system. We assembled the first transcriptome of D. longgicaudata using transcriptome sequencing and identified 162,621 unigenes for the Ashmead insects in response to fruit flies fed with different fruits (guava, mango, and carambola). We annotated these transcripts on both the gene and protein levels by aligning them to databases (e.g., NR, NT, KEGG, GO, PFAM, UniProt/SwissProt) and prediction software (e.g., SignalP, RNAMMER, TMHMM Sever). CPC2 and MIREAP were used to predict the potential noncoding RNAs and microRNAs, respectively. Based on these annotations, we found 43, 69, 60, 689, 26 and 14 transcripts encoding odorant-binding protein (OBP), chemosensory proteins (CSPs), gustatory receptor (GR), odorant receptor (OR), odorant ionotropic receptor (IR), and sensory neuron membrane protein (SNMP), respectively. Sequence analysis identified the conserved six Cys in OBP sequences and phylogenetic analysis further supported the identification of OBPs and CSPs. Furthermore, 9 OBPs, 13 CSPs, 3 GRs, 4IRs, 25 ORs, and 4 SNMPs were differentially expressed in the insects in response to fruit flies with different scents. These results support that the olfactory genes of the parasitoid wasps were specifically expressed in response to their hosts with different scents. Our findings improve our understanding of the behaviors of insects in the detection of their hosts on the molecular level. More importantly, it provides a valuable resource for D. longicaudata research and will benefit the IPM programs and other researchers in this filed.

scholarly journals Prediction and Characterization of RXLR Effectors in Pythium Species

2020 ◽  
Vol 33 (8) ◽  
pp. 1046-1058 ◽  
Author(s):  
Gan Ai ◽  
Kun Yang ◽  
Wenwu Ye ◽  
Yuee Tian ◽  
Yaxin Du ◽  
...  
Keyword(s):  
Genome Rearrangement ◽  
De Novo ◽  
Biological Control Agent ◽  
Protein Structures ◽  
Control Agent ◽  
Phytophthora Species ◽  
Host Cells ◽  
Pythium Species ◽  
Origin And Evolution ◽  
Rxlr Effectors

RXLR effectors, a class of secreted proteins that are transferred into host cells to manipulate host immunity, have been reported to widely exist in oomycetes, including those from genera Phytophthora, Hyaloperonospora, Albugo, and Saprolegnia. However, in Pythium species, no RXLR effector has yet been characterized, and the origin and evolution of such virulent effectors are still unknown. Here, we developed a modified regular expression method for de novo identification of RXLRs and characterized 359 putative RXLR effectors in nine Pythium species. Phylogenetic analysis revealed that all oomycetous RXLRs formed a single superfamily, suggesting that they might have a common ancestor. RXLR effectors from Pythium and Phytophthora species exhibited similar sequence features, protein structures, and genome locations. In particular, there were significantly more RXLR proteins in the mosquito biological control agent P. guiyangense than in the other eight Pythium species, and P. guiyangense RXLRs might be the result of gene duplication and genome rearrangement events, as indicated by synteny analysis. Expression pattern analysis of RXLR-encoding genes in the plant pathogen P. ultimum detected transcripts of the majority of the predicted RXLR genes, with some RXLR effectors induced in infection stages and one RXLR showing necrosis-inducing activity. Furthermore, all predicted RXLR genes were cloned from two biocontrol agents, P. oligandrum and P. periplocum, and three of the RXLR genes were found to induce a defense response in Nicotiana benthamiana. Taken together, our findings represent the first evidence of RXLR effectors in Pythium species, providing valuable information on their evolutionary patterns and the mechanisms of their interactions with diverse hosts.

scholarly journals Hybrid Genome Assembly and Evidence-Based Annotation of the Egg Parasitoid and Biological Control Agent Trichogramma brassicae

2020 ◽  
Vol 10 (10) ◽  
pp. 3533-3540 ◽  
Author(s):  
Kim B. Ferguson ◽  
Tore Kursch-Metz ◽  
Eveline C. Verhulst ◽  
Bart A. Pannebakker
Keyword(s):  
Biological Control ◽  
De Novo ◽  
Biological Control Agent ◽  
Egg Parasitoid ◽  
Control Agent ◽  
Evidence Based ◽  
Trichogramma Brassicae ◽  
A Genome ◽  
Hybrid Genome ◽  
Essential Resource

Trichogramma brassicae (Bezdenko) are egg parasitoids that are used throughout the world as biological control agents and in laboratories as model species. Despite this ubiquity, few genetic resources exist beyond COI, ITS2, and RAPD markers. Aided by a Wolbachia infection, a wild-caught strain from Germany was reared for low heterozygosity and sequenced in a hybrid de novo strategy, after which several assembling strategies were evaluated. The best assembly, derived from a DBG2OLC-based pipeline, yielded a genome of 235 Mbp made up of 1,572 contigs with an N50 of 556,663 bp. Following a rigorous ab initio-, homology-, and evidence-based annotation, 16,905 genes were annotated and functionally described. As an example of the utility of the genome, a simple ortholog cluster analysis was performed with sister species T. pretiosum, revealing over 6000 shared clusters and under 400 clusters unique to each species. The genome and transcriptome presented here provides an essential resource for comparative genomics of the commercially relevant genus Trichogramma, but also for research into molecular evolution, ecology, and breeding of T. brassicae.

scholarly journals Hybrid genome assembly and evidence-based annotation of the egg parasitoid and biological control agent Trichogramma brassicae

2020 ◽  
Author(s):  
K. B. Ferguson ◽  
T. Kursch-Metz ◽  
E. C. Verhulst ◽  
B. A. Pannebakker
Keyword(s):  
Biological Control ◽  
De Novo ◽  
Biological Control Agent ◽  
Egg Parasitoid ◽  
Control Agent ◽  
Evidence Based ◽  
Trichogramma Brassicae ◽  
A Genome ◽  
Hybrid Genome ◽  
Essential Resource

ABSTRACTTrichogramma brassicae (Bezdenko) are egg parasitoids that are used throughout the world as biological control agents and in laboratories as model species. Despite this ubiquity, few genetic resources exist beyond COI, ITS2, and RAPD markers. Aided by a Wolbachia infection, a wild-caught strain from Germany was reared for low heterozygosity and sequenced in a hybrid de novo strategy, after which several assembling strategies were evaluated. The best assembly, derived from a DBG2OLC-based pipeline, yielded a genome of 235 Mbp made up of 1,572 contigs with an N50 of 556,663 bp. Following a rigorous ab initio-, homology-, and evidence-based annotation, 16,905 genes were annotated and functionally described. As an example of the utility of the genome, a simple ortholog cluster analysis was performed with sister species T. pretiosum, revealing over 6000 shared clusters and under 400 clusters unique to each species. The genome and transcriptome presented here provides an essential resource for comparative genomics of the commercially relevant genus Trichogramma, but also for research into molecular evolution, ecology, and breeding of T. brassicae.

scholarly journals Unexpected parasitism of Douglas-fir seed chalcid limits biocontrol options for invasive Douglas-fir in New Zealand

2021 ◽  
Vol 74 (1) ◽  
pp. 70-77
Author(s):  
Sonia Lee ◽  
Simon V. Fowler ◽  
Claudia Lange ◽  
Lindsay A. Smith ◽  
Alison M. Evans
Keyword(s):  
Biological Control ◽  
New Zealand ◽  
Seed Production ◽  
Biocontrol Agent ◽  
Biological Control Agent ◽  
Parasitoid Wasp ◽  
Control Agent ◽  
Douglas Fir ◽  
Seed Predator ◽  
High Level

Douglas-fir seed chalcid (DFSC) Megastigmus spermotrophus, a small (3 mm long) host-specific seed-predatory wasp, was accidentally introduced into New Zealand in the 1920s. Concern over DFSC reducing Douglas-fir seed production in New Zealand led to an attempt at biocontrol in 1955 with the release, but failed establishment, of the small (2.5 mm long) parasitoid wasp, Mesopolobus spermotrophus. We investigated why DFSC causes little destruction of Douglas-fir seed in New Zealand (usually <20%) despite the apparent absence of major natural enemies. Douglas-fir seed collections from 13 New Zealand sites yielded the seed predator (DFSC) but also potential parasitoids, which were identified using morphology and partial COI DNA sequencing. DFSC destroyed only 0.15% of Douglas-fir seed. All parasitoids were identified as the pteromalid wasp, Mes. spermotrophus, the host-specific biocontrol agent released in 1955. Total parasitism was 48.5%, but levels at some sites approached 90%, with some evidence of density-dependence. The discovery of the parasitoid Mes. spermotrophus could indicate that the biocontrol agent released in 1955 did establish after all. Alternatively, Mes. spermotrophus could have arrived accidentally in more recent importations of Douglas-fir seed. The high level of parasitism of DFSC by Mes. spermotrophus is consistent with DFSC being under successful biological control in New Zealand. Suppression of DFSC populations will benefit commercial Douglas-fir seed production in New Zealand, but it also represents the likely loss of a potential biological control agent for wilding Douglas-fir.

scholarly journals Psix striaticeps (Dodd) (Hymenoptera, Scelionidae): an Old World parasitoid of stink bug eggs arrives in Florida, USA

2021 ◽  
Vol 87 ◽  
pp. 503-521
Author(s):  
Sarah Birkmire ◽  
Cory Penca ◽  
Elijah J. Talamas ◽  
Matthew R. Moore ◽  
Amanda C. Hodges
Keyword(s):  
Biological Control ◽  
Biological Control Agent ◽  
Parasitoid Wasp ◽  
Egg Parasitoid ◽  
Control Agent ◽  
Western Hemisphere ◽  
Stink Bug ◽  
Stink Bugs ◽  
Old World ◽  
Piezodorus Guildinii

Psix striaticeps (Dodd) is an egg-parasitoid wasp previously known only from the Old World. We report this species from twelve counties in Florida, which are the first records in the Western Hemisphere. It was collected in yellow cylinder traps and reared from the eggs of three stink bug species: Nezara viridula L., Chinavia marginata (Palisot de Beauvois), and Piezodorus guildinii (Westwood). A COI barcode analysis found a 100% match between the Floridian population and a specimen from South Africa. The prospects of using Ps. striaticeps as a biological control agent against exotic stink bugs are discussed.

scholarly journals First evidence of Ixodiphagus hookeri (Hymenoptera: Encyrtidae) parasitization in Finnish castor bean ticks (Ixodes ricinus)

2019 ◽  
Vol 79 (3-4) ◽  
pp. 395-404 ◽  
Author(s):  
Jani Jukka Sormunen ◽  
Ella Sippola ◽  
Kari Mikael Kaunisto ◽  
Eero Juhani Vesterinen ◽  
Ilari Eerikki Sääksjärvi
Keyword(s):  
Biological Control ◽  
Ixodes Ricinus ◽  
Biological Control Agent ◽  
Parasitoid Wasp ◽  
Control Agent ◽  
Northern Europe ◽  
Infection Rates ◽  
Ixodiphagus Hookeri ◽  
The Status ◽  
Initial Discovery

AbstractIxodiphagus hookeri (Hymenoptera: Encyrtidae) is a parasitoid wasp specialized in parasitizing the larvae and nymphs of ticks (Acari: Ixodidae). As parasitized ticks die prior to reproduction, I. hookeri is seen as a prime biological control agent candidate. Despite this, little is known of their occurrence or ecology in northern Europe. The main aim of the current study was to determine whether adult wasps or parasitized ticks can be found from a tick-infested island in southwestern Finland, using field collections and molecular methods. Following the initial discovery of an adult I. hookeri female on Seili Island, we set out to collect further specimens via sweep netting and Malaise trappings between May and October 2017. Furthermore, 1310 Ixodes ricinus (1220 nymphs, 90 adults) collected from the island during 2012–2014 were screened for I. hookeri DNA using qPCR. Whereas no further wasp specimens could be collected via sweep netting or Malaise trappings, I. hookeri DNA was consistently detected in I. ricinus nymphs (annual minimum infection rates in 2012, 2013, and 2014: 2.3, 0.4, and 0.5%, respectively), whereas all adult samples were negative. Although the annually repeated detections of parasitized ticks suggest that the wasp inhabits the island, further field and molecular surveys are needed to more comprehensively determine the status and stability of the population.

scholarly journals De novo assembly of the Pasteuria penetrans genome reveals high plasticity, host dependency, and BclA-like collagens

2018 ◽  
Author(s):  
Jamie N Orr ◽  
Tim H Mauchline ◽  
Peter J Cock ◽  
Vivian C Blok ◽  
Keith G Davies
Keyword(s):  
Genomic Dna ◽  
De Novo ◽  
Biological Control Agent ◽  
Control Agent ◽  
Complete Sequence ◽  
Parasitic Nematodes ◽  
High Plasticity ◽  
Pasteuria Penetrans ◽  
Culture Methods

1.ABSTRACTPasteuria penetrans is a gram-positive endospore forming bacterial parasite of Meloidogyne spp. the most economically damaging genus of plant parasitic nematodes globally. The obligate antagonistic nature of P. penetrans makes it an attractive candidate biological control agent. However, deployment of P. penetrans for this purpose is inhibited by a lack of understanding of its metabolism and the molecular mechanics underpinning parasitism of the host, in particular the initial attachment of the endospore to the nematode cuticle. Several attempts to assemble the genomes of species within this genus have been unsuccessful. Primarily this is due to the obligate parasitic nature of the bacterium which makes obtaining genomic DNA of sufficient quantity and quality which is free from contamination challenging. Taking advantage of recent developments in whole genome amplification, long read sequencing platforms, and assembly algorithms, we have developed a protocol to generate large quantities of high molecular weight genomic DNA from a small number of purified endospores. We demonstrate this method via genomic assembly of P. penetrans. This assembly reveals a reduced genome of 2.64Mbp estimated to represent 86% of the complete sequence; its reduced metabolism reflects widespread reliance on the host and possibly associated organisms. Additionally, apparent expansion of transposases and prediction of partial competence pathways suggest a high degree of genomic plasticity. Phylogenetic analysis places our sequence within the Bacilli, and most closely related to Thermoactinomyces species. Seventeen predicted BclA-like proteins are identified which may be involved in the determination of attachment specificity. This resource may be used to develop in vitro culture methods and to investigate the genetic and molecular basis of attachment specificity.

scholarly journals Comparison of the toxicity and repellency of two conventional neonicotinoids and a coconut-derived insecticide soap toward the parasitoid wasp Aphelinus mali Haldeman, 1851

2020 ◽  
Vol 115 (1) ◽  
pp. 97
Author(s):  
Asgar EBADOLLAHI ◽  
Reza SADEGHI
Keyword(s):  
Biological Control ◽  
Exposure Time ◽  
Biological Control Agent ◽  
Parasitoid Wasp ◽  
Control Agent ◽  
Eriosoma Lanigerum ◽  
Woolly Apple Aphid ◽  
Aphelinus Mali ◽  
The World ◽  
Filter Papers

<p><strong></strong>The parasitoid wasp <em>Aphelinus mali</em>,Haldeman, 1851 (Hymenoptera: Aphelinidae) is the most important biological control agent against the woolly apple aphid,<em> Eriosoma lanigerum</em> (Hausemann, 1802) (Hemiptera: Aphididae), which is an important apple orchards pest throughout the world. Based on the importance of using low-risk compounds to protect beneficial agents, the present study was carried out to evaluate the toxic and repellent effects of two conventional chemicals (imidacloprid and thiacloprid) and coconut-derived biopesticide soap (Palizin<sup>Ò</sup>) toward <em>A. mali</em>. The results of residual bioassays on apple leaf discs indicated that imidacloprid after 24 h and insecticide soap after 72 h exposure time categorized at the highest and no/little toxicity rates, respectively. Ingestion bioassays on filter papers revealed that imidacloprid and thiacloprid had moderate toxicity rate, while insecticide soap had a low-level toxicity rate. Repellency test at Y-tube olfactometer showed that the repellent effects of both chemicals were more than that of insecticide soap. It is concluded that coconut-derived soap was compatible with the parasitoid activity, and the caution should be paid when including the two neonicotinoid insecticides imidacloprid and thiacloprid for <em>E. lanigerum</em> management.</p>

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