Browsing by Author "Koppel, Amanda Leigh"

Now showing 1 - 3 of 3
  • Thumbnail Image
    Biology and Management of the Green Stink Bug
    Kamminga, Katherine; Koppel, Amanda Leigh; Herbert, D. Ames Jr.; Kuhar, Thomas P. (Entomological Society of America, 2012-12-01)
    The green stink bug, Acrosternum hilare (Say) [Chinavia hilaris (Say)] (Hemiptera: Pentatomidae) is one of the most damaging native stink bug species in the United States. It is a pest of economic importance in a variety of commodities, including cotton (Gossypium hirsutum L.), soybeans [Glycine max (L.) Merr.], tomatoes (Solanum lycopersicum L.), and peaches [Prunus persica (L.) Batsch]. Stink bug feeding can result in cosmetic damage as well as reduced quality and yield. Acrosternum hilare and other stink bugs have become a major challenge to integrated pest management systems because control options are basically limited to the application of broad-spectrum insecticides such as organophosphates, carbamates, and pyrethroids. However, neonicotinoids are generally effective for control of this stink bug and may be less disruptive to natural enemies. Further options for stink bug management that are being explored include the use of trap crops and enhancing beneficial parasitoid populations. The green stink bug is native and found throughout the United States. It has a wide host range, and is a pest of many agricultural commodities. The green stink bug can cause feeding injury to fruit, vegetable, and field crops that may require preventative management. Many strategies are available for its control, which include multiple chemical, cultural, and biological options. Broad-spectrum insecticides such as pyrethroids and organophosphates, as well as the less toxic neonicotinoids, are efficacious against the green stink bug. Cultural options, including trap cropping and the planting of resistant varieties, have been documented as decreasing crop injury by stink bugs. In addition, there are multiple natural enemies that reduce population numbers.
  • Thumbnail Image
    Stink bug egg studies in southeastern Virginia: parasitoid survey, and susceptibility and chorion permeability to insecticides
    Koppel, Amanda Leigh (Virginia Tech, 2010-03-26)
    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 "scab", 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 λ-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 (Stål) 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 Xi'an. Parasitization of eggs was noted, and the parasitoids were identified as Trissolcus halyomorphae Yang (Scelionidae: Hymenoptera) by K.A. Hoelmer (USDA-ARS).
  • Thumbnail Image
    Using Microscopy to Assess Chorion Structural Integrity and Parasitoid Oviposition Sites on Stink Bug (Hemiptera: Pentatomidae) Eggs
    Koppel, Amanda Leigh; Herbert, D. Ames Jr.; Westbrook, E. W. (Cambridge University Press, 2011-02)
    Previous efficacy studies found that many insecticides used by growers could be having an adverse effect on egg parasitoids (Telenomus podisi) developing in the eggs of the brown stink bug (Euschistus servus), while unhatched stink bugs experienced lower levels of mortality. One plausible explanation for this was that insecticides might enter parasitized eggs more readily via oviposition wounds. Parasitized E. servus eggs, as well as nonparasitized stink bug (Acrosternum hilare, E. servus, Murgantia histrionica, and Podisus macoliventris) eggs, were examined using electron microscopy. Egg response to perforation by a tungsten probe served as a control. Microscopy images depicted the chorion surface as characterized by a matrix of ridges and micropylar processes in a ring around the margin of the operculum. Observations of oviposition sites showed a "scab" formed where the ovipositor penetrated the chorion, and at sites penetrated by the probe. These formations appeared to be the result of fluids from inside the egg leaking out, drying, and hardening after oviposition or probe perforation, suggesting that the response was not due to substances secreted by the parasitoid. Further, no open wounds or holes were seen to increase the possibility of insecticides entering parasitized eggs.