Virginia Tech
    • Log in
    View Item 
    •   VTechWorks Home
    • ETDs: Virginia Tech Electronic Theses and Dissertations
    • Doctoral Dissertations
    • View Item
    •   VTechWorks Home
    • ETDs: Virginia Tech Electronic Theses and Dissertations
    • Doctoral Dissertations
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Stink bug egg studies in southeastern Virginia: parasitoid survey, and susceptibility and chorion permeability to insecticides

    Thumbnail
    View/Open
    Koppel_AL_D_2010.pdf (7.135Mb)
    Downloads: 358
    Date
    2010-03-26
    Author
    Koppel, Amanda Leigh
    Metadata
    Show full item record
    Abstract
    Currently, there is little known about stink bug (Hemiptera: Pentatomidae) eggs, their natural enemies, and their susceptibility to insecticides. A survey of stink bug egg parasitoids was conducted in row crops and vegetables in eastern Virginia. Parasitization was highest in Euschistus servus (Say) with 89.7% and 49.2% of egg masses and individual eggs parasitized, respectively, followed by Acrosternum hilare (Say), with nearly half of all individual eggs parasitized. The most common parasitoid was Telenomus podisi Ashmead (Hymenoptera: Scelionidae). Laboratory egg-dip bioassays and field applications of acephate, lambda-cyhalothrin, spinosad, and thiamethoxam, were carried out to determine efficacy against nonparasitized E. servus and A. hilare eggs, and T. podisi embryos developing in E. servus eggs. Results showed that eggs of both species were susceptible to insecticides, that there was little difference among insecticides, but there was generally greater mortality in field-treated versus dipped eggs. Developing T. podisi were generally more susceptible to insecticides than stink bugs. Scanning electron microscopy was used to investigate oviposition sites as possible sites of insecticide movement into eggs. Oviposition wounds and holes made by a tungsten probe were similarly sealed by a â scabâ , so it was not clear whether these wounds allow for increased insecticide movement into parasitized eggs. Differences in chorion permeability of non-parasitized and parasitized eggs were compared by immersing them in solutions containing different 14C-ammended insecticides at field application rates for 0, 30, 120 or 240 minutes. Results showed that insecticide movement into the egg increased significantly with immersion time for both acephate and lambda-cyhalothrin, but there were no significant differences between nonparasitized and parasitized eggs. Neither immersion time nor egg status was significant for thiamethoxam. A model was constructed that predicts amount of insecticide entering the egg at any given time. An 8-week survey for the brown marmorated stink bug, Halyomorpha halys (StÃ¥l) was conducted in Beijing and five other cities in China. Incidence of egg parasitism was recorded. Results showed that H. halys utilized at least four different plants throughout the summer, and insects were found in Nanjing, Kunming, and Xiâ an. Parasitization of eggs was noted, and the parasitoids were identified as Trissolcus halyomorphae Yang (Scelionidae: Hymenoptera) by K.A. Hoelmer (USDA-ARS).
    URI
    http://hdl.handle.net/10919/37540
    Collections
    • Doctoral Dissertations [14916]

    If you believe that any material in VTechWorks should be removed, please see our policy and procedure for Requesting that Material be Amended or Removed. All takedown requests will be promptly acknowledged and investigated.

    Virginia Tech | University Libraries | Contact Us
     

     

    VTechWorks

    AboutPoliciesHelp

    Browse

    All of VTechWorksCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

    My Account

    Log inRegister

    Statistics

    View Usage Statistics

    If you believe that any material in VTechWorks should be removed, please see our policy and procedure for Requesting that Material be Amended or Removed. All takedown requests will be promptly acknowledged and investigated.

    Virginia Tech | University Libraries | Contact Us