Department of Entomology
  • About
    • At a Glance
    • Welcome
    • Code of Conduct
    • Diversity, Equity, and Inclusion >
      • DEI Working Group
      • Resources
    • Departmental History
    • For Alumni
    • Support Entomology >
      • Steinhauer Scholarship Fund
    • Contact >
      • Directions
  • News
    • News
    • Seminar Blog
    • Seminar Schedule
    • Awards
  • People
    • Faculty
    • Post Docs
    • Students
    • Staff
    • Alumni
    • For PI/Faculty
    • Proposal Resources
  • Academics
    • Graduate >
      • Admissions
      • MS Degree Requirements
      • PhD Degree Requirements
      • Graduate Student Resources
      • Forms for Grad Students
      • Financial Assistance
      • Award & Funding Opportunities
      • Entomology Student Organization
    • Online Masters in Applied Entomology
    • Undergraduate >
      • Entomology Minor
      • Honors Program
  • Research
    • IPM & Biological Control of Agricultural, Urban & Forest Pests
    • Ecology, Conservation, Restoration, Climate Change >
      • Pollinator Science and Apiculture
    • Evolution, Systematics and Evo-Devo
    • Genetics & Genomics and Medical Entomology
  • Extension/Outreach
    • Educational Outreach
    • Insect Camp
    • Insect Drawings
    • Insect Identification
    • Pesticide Education and Assessment Program
    • Plant Diagnostic Laboratory (PDL)

A Bug’s Bug’s Life

4/21/2016

 
Picture
Since its accidental introduction into the Allentown, Pennsylvania area in the late 1990’s, the brown marmorated stink bug (BMSB), Halyomorpha halys, has established itself as a severe pest across much of the eastern United States.  Much to farmers’ dismay, most conventional management techniques, including insecticides, do not effectively control the insect. This fact spurred the development of a working group in 2012 to research potential management strategies for the brown marmorated stink bug. The work of Chris Taylor investigating the importance of BMSB symbionts was part of this research. Taylor’s research focused on the relationship between the brown marmorated stink bug and a species of bacteria (Candidatus Pantoea carbekii) that resides in the insect’s gut, as well as on the surfaces of BMSB egg masses. He conducted a series of laboratory experiments looking at symbiont acquisition, nymphal survival, and fecundity under a variety of conditions.

Are brown marmorated stinkbugs reliant on the bacteria smeared on egg mass surfaces?
Previous research has shown varying levels of dependence on symbionts by different stink bug species, who obtain these symbionts be feeding on bacteria smeared on the surface of the egg mass. This resulted in the need to first confirm the level of symbiont reliance by the brown marmorated stink bug. To do this, aposymbiotic insects (those without symbionts) were generated by surface sterilizing egg masses using bleach and subsequently rearing these insects through all life stages. Survival, 
development time, and egg mass production was tracked and compared to stink bugs allowed to obtain their symbiont. Results 
indicated that BMSB is heavily reliant on its symbiont, showing significantly reduced survival, increased number of days to 
developmental peak, and reduced fecundity in aposymbiotic insects.

Does environmental stress impact symbiont transmission or survival after transmission?
Previous research has shown that some insects lose their symbionts under higher temperature conditions. In the case of BMSB, the effects of heat on the symbionts present both on the egg mass surface, and within the gut of the insect, had never previously been studied. To determine the effects of temperature on egg mass surface symbionts, egg masses were exposed to three fluctuating temperature conditions meant to mimic different mid-Atlantic summer conditions. The temperatures were classified as ‘normal’, ‘above average’ and ‘extreme’. The egg masses were exposed to one of these three temperatures, and returned to 
optimal rearing conditions as soon the eggs hatched.   Hatch rate was calculated for each egg mass, and the ‘extreme’ condition was found to significantly reduce hatch rates and was therefore discarded. Hatch rate, survival, and percent inoculation were calculated for the ‘normal’ and ‘above average’ conditions, and no effect of temperature on the symbiont was detected. 
Next, Chris wanted to look at symbiont survival within the gut under heat stress. He settled for comparisons as 25 versus 30 degrees Celsius (mimicking previous studies) due to an inability to use the fluctuating conditions chambers for extended periods of time. Looking at the effects of these two temperatures on symbionts within the gut, a significant decrease in survival over time was seen in insects exposed to the higher temperature that were allowed to obtain their symbionts at birth. Additionally, decreases in fecundity were seen in the bugs at the higher temperature, as well as a drastic reduction in the number of bugs that still had their symbionts as adults. 
Results from these experiments indicated that the symbionts present on the surface of the egg mass are not likely affected by heat stress, but that heat stress over time has the potential to kill the symbiont within the gut of the bug.

Can antimicrobial products remove the symbiont from the egg mass, and can this be used as a possible management strategy?

The final experiments investigating the relationship between the brown marmorated stink bug and its’ gut symbionts addressed the potential for exploiting this relationship as a possible avenue of BMSB control.  Using commercially available products with antimicrobial properties, Chris treated the symbionts on the egg mass surface like any other field crop disease, and tested to determine if any of these products had the potential to sterilize the egg mass surfaces. A total of six products were tested, and nymphs from each treatment were screened for the presence of gut symbionts. Of these six products, three were found to significantly reduce the number of BMSB able to obtain their symbiont from the egg mass surface. 
The findings of Chris Taylor’s research contribute much to the understanding of the complicated relationship between this insect and its symbionts. Future research is needed to determine sterilization efficacy of these products in a field setting, and to tease apart the different abiotic conditions that may limit BMSB’s host range.

Further Reading:

Taylor CM, Coffey PL, DeLay BD, Dively GP (2014) The Importance of Gut Symbionts in the Development of the Brown Marmorated Stink Bug, Halyomorpha halys (Stål). PLoS ONE 9(3): e90312. doi:10.1371/journal.pone.0090312

Picture
About the Author: 

Veronica Johnson is a Master’s student whose research focuses on determining the role of different post-harvest litter management practices in the degradation of Cry proteins in genetically modified Bt corn. She is also looking to determine the effects of winter temperature and precipitation on both tissue decomposition and protein degradation under these various litter management practices.


Comments are closed.

    Categories

    All
    Awards
    Colloquium
    Faculty Spotlight
    Fall 2013 Colloquium
    Fall 2014 Colloquium
    Fall 2015 Colloquium
    Fall 2016 Colloquium
    Featured
    Innovation
    News
    Publications
    Science Projects
    SESYNC
    Spring 2014 Colloquium
    Spring 2015 Colloquium
    Spring 2016 Colloquium
    Talks
    Undergraduate

    Archives

    April 2025
    March 2025
    February 2025
    December 2024
    November 2024
    October 2024
    June 2024
    May 2024
    April 2024
    March 2024
    December 2023
    November 2023
    October 2023
    September 2023
    August 2023
    July 2023
    June 2023
    May 2023
    April 2023
    March 2023
    February 2023
    January 2023
    December 2022
    November 2022
    October 2022
    September 2022
    August 2022
    July 2022
    May 2022
    April 2022
    March 2022
    February 2022
    January 2022
    December 2021
    November 2021
    October 2021
    September 2021
    August 2021
    July 2021
    June 2021
    May 2021
    April 2021
    March 2021
    February 2021
    January 2021
    December 2020
    November 2020
    October 2020
    September 2020
    August 2020
    July 2020
    June 2020
    May 2020
    April 2020
    March 2020
    February 2020
    December 2019
    November 2019
    October 2019
    September 2019
    August 2019
    July 2019
    June 2019
    May 2019
    April 2019
    March 2019
    February 2019
    January 2019
    December 2018
    November 2018
    October 2018
    September 2018
    August 2018
    July 2018
    June 2018
    May 2018
    April 2018
    March 2018
    February 2018
    December 2017
    November 2017
    October 2017
    September 2017
    June 2017
    May 2017
    April 2017
    March 2017
    February 2017
    January 2017
    December 2016
    November 2016
    October 2016
    September 2016
    August 2016
    June 2016
    May 2016
    April 2016
    March 2016
    February 2016
    January 2016
    December 2015
    November 2015
    October 2015
    September 2015
    August 2015
    July 2015
    June 2015
    May 2015
    April 2015
    March 2015
    February 2015
    January 2015
    December 2014
    November 2014
    October 2014
    September 2014
    August 2014
    June 2014
    May 2014
    April 2014
    March 2014
    February 2014
    January 2014
    December 2013
    November 2013
    October 2013
    September 2013

    RSS Feed

Picture
Picture
Picture
Department of Entomology 
University of Maryland 
4112 Plant Sciences Building 
College Park, MD 20742-4454
USA

Telephone: 301.405.3911 
Fax: 301.314.9290
Picture
Web Accessibility
  • About
    • At a Glance
    • Welcome
    • Code of Conduct
    • Diversity, Equity, and Inclusion >
      • DEI Working Group
      • Resources
    • Departmental History
    • For Alumni
    • Support Entomology >
      • Steinhauer Scholarship Fund
    • Contact >
      • Directions
  • News
    • News
    • Seminar Blog
    • Seminar Schedule
    • Awards
  • People
    • Faculty
    • Post Docs
    • Students
    • Staff
    • Alumni
    • For PI/Faculty
    • Proposal Resources
  • Academics
    • Graduate >
      • Admissions
      • MS Degree Requirements
      • PhD Degree Requirements
      • Graduate Student Resources
      • Forms for Grad Students
      • Financial Assistance
      • Award & Funding Opportunities
      • Entomology Student Organization
    • Online Masters in Applied Entomology
    • Undergraduate >
      • Entomology Minor
      • Honors Program
  • Research
    • IPM & Biological Control of Agricultural, Urban & Forest Pests
    • Ecology, Conservation, Restoration, Climate Change >
      • Pollinator Science and Apiculture
    • Evolution, Systematics and Evo-Devo
    • Genetics & Genomics and Medical Entomology
  • Extension/Outreach
    • Educational Outreach
    • Insect Camp
    • Insect Drawings
    • Insect Identification
    • Pesticide Education and Assessment Program
    • Plant Diagnostic Laboratory (PDL)