Survey of bacteria associated with western corn rootworm life stages reveals no difference between insects reared in different soils

Abstract Western corn rootworm (Diabrotica virgifera virgifera LeConte) is a serious pest of maize (Zea mays L.) in North America and parts of Europe. With most of its life cycle spent in the soil feeding on maize root tissues, this insect is likely to encounter and interact with a wide range of soil and rhizosphere microbes. Our knowledge of the role of microbes in pest management and plant health remains woefully incomplete, yet that knowledge could play an important role in effective pest management strategies. For this study, insects were reared on maize in soils from different locations. Insects from two different laboratory colonies (a diapausing and a non-diapausing colony) were sampled at each life stage to determine the possible core bacteriome. Additionally, soil was sampled at each life stage and resulting bacteria were identified to determine the possible contribution of soil to the rootworm bacteriome, if any. We analyzed the V4 hypervariable region of bacterial 16S rRNA genes with Illumina MiSeq to survey the different species of bacteria associated with the insects and the soils. The bacterial community associated with insects was significantly different from that in the soil. Some differences appear to exist between insects from non-diapausing and diapausing colonies while no significant differences in community composition existed between the insects reared on different soils. Despite differences in the bacteria present in immature stages and in male and female adults, there is a possible core bacteriome of approximately 16 operational taxonomic units (i.e., present across all life stages). This research may provide insights into Bt resistance development, improved nutrition in artificial rearing systems, and new management strategies.

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Survey of bacteria associated with western corn rootworm life stages reveals no difference between insects reared in different soils

10.1101/365296 ◽

2018 ◽

Author(s):

Dalton C. Ludwick ◽

Aaron C. Ericsson ◽

Lisa N. Meihls ◽

Michelle L.J. Gregory ◽

Deborah L. Finke ◽

...

Keyword(s):

Pest Management ◽

Life Stage ◽

Diabrotica Virgifera Virgifera ◽

Western Corn Rootworm ◽

16S Rrna Genes ◽

Rrna Genes ◽

Corn Rootworm ◽

Life Stages ◽

Wide Range ◽

Different Soils

AbstractWestern corn rootworm (Diabrotica virgifera virgifera LeConte) is a serious pest of maize (Zea mays L.) in North America and parts of Europe. With most of its life cycle spent in the soil feeding on maize root tissues, this insect is likely to encounter and interact with a wide range of soil and rhizosphere microbes. Our knowledge of the role of microbes in pest management and plant health remains incomplete. An important component of an effective pest management strategy is to know which microorganisms are present that could play a role in life history or management. For this study, insects were reared in soils from different locations. Insects were sampled at each life stage to determine the possible core bacteriome. Additionally, soil was sampled at each life stage and resulting bacteria were identified to determine the contribution of soil to the rootworm bacteriome, if any. We analyzed the V4 hypervariable region of bacterial 16S rRNA genes with Illumina MiSeq to survey the different species of bacteria associated with the insects and the soils. The bacterial community associated with insects was significantly different from that in the soil. Some differences appear to exist between insects from non-diapausing and diapausing colonies while no significant differences in community composition existed between the insects reared on different soils. Despite differences in the bacteria present in immature stages and in male and female adults, there is a possible core bacteriome of approximately 16 operational taxonomic units (i.e., present across all life stages). This research may give insights into how resistance to Bt develops, improved nutrition in artificial rearing systems, and new management strategies.

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Western Corn Rootworm (Diabrotica virgifera virgifera LeConte) in Europe: Current Status and Sustainable Pest Management

Insects ◽

10.3390/insects12030195 ◽

2021 ◽

Vol 12 (3) ◽

pp. 195

Author(s):

Renata Bažok ◽

Darija Lemić ◽

Francesca Chiarini ◽

Lorenzo Furlan

Keyword(s):

Pest Management ◽

Management Strategies ◽

Diabrotica Virgifera Virgifera ◽

Western Corn Rootworm ◽

European Countries ◽

Corn Rootworm ◽

Diabrotica Virgifera ◽

Research Activities ◽

Diabrotica Virgifera Virgifera Leconte ◽

The Eu

Western corn rootworm (WCR), or Diabrotica virgifera virgifera LeConte, became a very serious quarantine maize pest in Europe in the mid-1990s. Between 1995 and 2010, European countries were involved in international projects to share information and plan common research for integrated pest management (IPM) implementation. Since 2011, however, common efforts have declined, and an overview of WCR population spread, density, and research is in serious need of update. Therefore, we retained that it was necessary to (1) summarize the research activities carried out in the last 12 years in various countries and the research topics addressed, and analyze how these activities have contributed to IPM for WCR and (2) present the current distribution of WCR in the EU and analyze the current population levels in different European countries, focusing on different management strategies. A review of scientific papers published from 2008 to 2020, in addition to direct interviews with experts in charge of WCR management in a range of European countries, was conducted. Over the past 12 years, scientists in Europe have continued their research activities to investigate various aspects of WCR management by implementing several approaches to WCR control. A considerable amount of new knowledge has been produced, contributing to the development of pest management strategies applicable in EU farming systems. Among the 10 EU countries analyzed, there is no country reporting economic damage on a large scale. Thanks to intensive research leading to specific agricultural practices and the EU Common Agricultural Policy, there are crop-rotation-based solutions that can adequately control this pest avoiding insecticide use.

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Partial characterization of Bt resistance and the bacteriome of western corn rootworm

10.32469/10355/66102 ◽

2018 ◽

Author(s):

◽

Dalton C. Ludwick

Keyword(s):

New Technologies ◽

Management Strategies ◽

Diabrotica Virgifera Virgifera ◽

Western Corn Rootworm ◽

Control Measures ◽

Corn Rootworm ◽

Diabrotica Barberi ◽

The Usa ◽

Diabrotica Virgifera Virgifera Leconte ◽

Northern Corn Rootworm

Western corn rootworm (Diabrotica virgifera virgifera LeConte) and northern corn rootworm (Diabrotica barberi (Smith and Lawrence)) are major pests of maize in the USA. These pests have been managed with a variety of tactics over the last century. Both Diabrotica spp. have adapted to crop rotation in different ways in certain regions of the USA as well as to some of the insecticides targeted at them. D. v. virgifera has adapted to more of the chemical control measures and transgenic control methods. Discussed in this review are the challenges associated with managing both species, and how current management strategies might be combined and implemented to help manage damage from these species. Also, we discuss the potential for new technologies, such as RNA interference, to be used in the future.

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RNAi for Western Corn Rootworm Management: Lessons Learned, Challenges, and Future Directions

Insects ◽

10.3390/insects13010057 ◽

2022 ◽

Vol 13 (1) ◽

pp. 57

Author(s):

Molly Darlington ◽

Jordan D. Reinders ◽

Amit Sethi ◽

Albert L. Lu ◽

Partha Ramaseshadri ◽

...

Keyword(s):

Environmental Protection Agency ◽

Management Strategies ◽

Housekeeping Genes ◽

Diabrotica Virgifera Virgifera ◽

The United States ◽

Western Corn Rootworm ◽

Lessons Learned ◽

Corn Rootworm ◽

In Planta ◽

Commercial Use

The western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte, is considered one of the most economically important pests of maize (Zea mays L.) in the United States (U.S.) Corn Belt with costs of management and yield losses exceeding USD ~1–2 billion annually. WCR management has proven challenging given the ability of this insect to evolve resistance to multiple management strategies including synthetic insecticides, cultural practices, and plant-incorporated protectants, generating a constant need to develop new management tools. One of the most recent developments is maize expressing double-stranded hairpin RNA structures targeting housekeeping genes, which triggers an RNA interference (RNAi) response and eventually leads to insect death. Following the first description of in planta RNAi in 2007, traits targeting multiple genes have been explored. In June 2017, the U.S. Environmental Protection Agency approved the first in planta RNAi product against insects for commercial use. This product expresses a dsRNA targeting the WCR snf7 gene in combination with Bt proteins (Cry3Bb1 and Cry34Ab1/Cry35Ab1) to improve trait durability and will be introduced for commercial use in 2022.

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Differences in the Diversity and Structure of the Gut Microbiome in Different Life Stages of the American Cockroach (Periplaneta americana)

10.21203/rs.3.rs-16743/v1 ◽

2020 ◽

Author(s):

Zhiyu Chen ◽

Bin Yang ◽

Peiyu Ou ◽

Xiaobao Jin

Keyword(s):

Gut Microbiome ◽

Metabolic Pathways ◽

Periplaneta Americana ◽

Life Stage ◽

American Cockroach ◽

16S Rrna Genes ◽

Rrna Genes ◽

Functional Genes ◽

Life Stages ◽

Relative Abundances

Abstract Gut microbes play critical roles in host nutrition, physiology, and behavior. Periplaneta americana is a famous urban pest which is widely distributed in the tropics and subtropics, but very few information is available on the gut microbiome of Periplaneta americana, particularly in its different life stages. Here, we characterized the diversity and structure of gut microbiome in eggs, nymph and adult life stages of Periplaneta americana using high-throughput 16S rRNA genes sequencing. Both the results of Alpha- and Beta-diversity analysis showed the diversity and structure of gut microbiome were significant different among the eggs, nymph and adult stages. The result of species distribution showed the predominant phyla in three life stages were Bacteroidetes , Firmicutes and Proteobacteria , but the relative abundances of these bacteria were significant different among each life stage. 1,169 operational taxonomic units were shared by three stages, which indicating the gut microbiome may be inherited to offspring from parents of Periplaneta americana. According to the prediction of functional genes in metabolic pathways, most of them were distributed in the metabolic pathways of basic physiology such as nutrition, growth, development and immunity, etc. The relative abundances of functional genes in metabolic pathways were significant different among life stages of Periplaneta americana, indicating the gut microbiome might play an important role in the physiology across its different life stages. This study revealed the diversity and structure of gut microbiome in different life stages of Periplaneta americana, which may contribute to us to understand it’s physiology and behaviors.

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Parameters for Successful Parental RNAi as An Insect Pest Management Tool in Western Corn Rootworm, Diabrotica virgifera virgifera

Genes ◽

10.3390/genes8010007 ◽

2016 ◽

Vol 8 (1) ◽

pp. 7 ◽

Cited By ~ 9

Author(s):

Ana Vélez ◽

Elane Fishilevich ◽

Natalie Matz ◽

Nicholas Storer ◽

Kenneth Narva ◽

...

Keyword(s):

Pest Management ◽

Insect Pest ◽

Diabrotica Virgifera Virgifera ◽

Western Corn Rootworm ◽

Management Tool ◽

Corn Rootworm ◽

Insect Pest Management ◽

Diabrotica Virgifera

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Comparing Populations of Western Corn Rootworm (Coleoptera: Chrysomelidae) in Regions With and Without a History of Injury to Cry3 Corn

Journal of Economic Entomology ◽

10.1093/jee/toaa106 ◽

2020 ◽

Vol 113 (4) ◽

pp. 1839-1849

Author(s):

Coy R St. Clair ◽

Graham P Head ◽

Aaron J Gassmann

Keyword(s):

Management Strategies ◽

Diabrotica Virgifera Virgifera ◽

Western Corn Rootworm ◽

Management Tool ◽

Bt Corn ◽

Corn Rootworm ◽

Root Injury ◽

Important Pest ◽

Bacterium Bacillus ◽

Management Tactics

Abstract Transgenic corn expressing insecticidal proteins derived from the bacterium Bacillus thuringiensis (Bt) is an important pest management tool. Western corn rootworm, Diabrotica virgifera virgifera LeConte, is a key pest of corn in the midwestern United States that has developed field-evolved resistance to all available Bt traits. The first Bt trait to be commercialized for management of rootworm was Cry3Bb1 in 2003, and field-evolved resistance appeared in 2009. In this study, we examined fields in counties where greater-than-expected injury to Cry3 (Cry3Bb1 or mCry3A) corn roots (>1 node) had previously been reported (problem counties) and counties where injury had not been reported (non-problem counties). Four to eight fields were sampled per county in 2015, 2016, and 2017 to quantify rootworm abundance, root injury, Cry3Bb1resistance, and rootworm management strategies. Rootworm abundance, root injury, and resistance to Cry3Bb1 did not differ between county types. Management tactics differed between county types, with problem counties growing more corn, using more soil insecticide, and growing more Cry34/35Ab1 corn. Additionally, a comparison of root injury to Bt and non-Bt corn within fields indicated that farmers derived an economic benefit from planting Bt corn to manage corn rootworm. Our results suggest that rootworm populations are similar between problem and non-problem counties in Iowa due to similar levels of selection pressure on Cry3 corn, but problem county fields have applied more management tactics due to previous rootworm issues in the area.

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