Year of Publication

2022

Degree Name

Doctor of Philosophy (PhD)

Document Type

Doctoral Dissertation

College

Agriculture, Food and Environment

Department/School/Program

Entomology

First Advisor

Dr. Ricardo Bessin

Abstract

Invasive species can be very disruptive to established integrated pest management programs. They can cause increases in broad-spectrum insecticide applications with variable effectiveness to mitigate damage. However, not all introduced species develop invasive characteristics; often, many introduced species go undetected. It is not until a species begins to cause economic damage to commodities essential to humans that it becomes classified as an invasive pest. Many challenges arise with the management of invasive pests due to lack of understanding of their biology, behavior, and absence of natural enemies in their introduced range. This often results in poor management and population outbreaks in the first years following introduction. This is the situation with brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae). Halyomorpha halys is an invasive pest from Asia that was first identified in the United States in Allentown, PA, during the late-1990s. H. halys’ broad host range and large populations threaten many crops by reducing produce and grain marketability through feeding injury. For organic producers, insecticide applications are ineffective and alternative management strategies are needed. Most research on H. halys has been conducted on tree fruit and nuts, with limited research on vegetable crops, including sweet corn, peppers, tomatoes, and soybeans. This research focuses on managing H. halys on small acreage farms and organic vegetable systems using population monitoring, habitat manipulation in the form of trap cropping, attract-and-kill methods, and evaluating potential natural enemies attacking H. halys egg and nymphal stages. These studies found that sticky-panel traps baited with H. halys aggregation pheromone lures placed outside agriculture fields can be used for season-long population monitoring for both adult and nymphal stages. Additionally, these traps can gauge field populations to evaluate pest management strategies. Deploying a polyculture trap crop of sunflower and Japanese millet around a bell pepper crop reduced H. halys presence in peppers and significantly reduced feeding damage. Evaluation of attract-and-kill (AK) strategies using insecticide-impregnated netting baited with H. halys aggregation pheromone lures reduced stink bug densities and feeding in sweet corn. There is potential that AK control tactics can be scaled up from managing single species to being a season-long management tool for several insect pests or reducing H. halys levels for small, diversified farms. Sentinel egg masses were used to surveys natural enemies of H. halys eggs and to detect Trissolcus japonicus (Ashmed) in Kentucky, an egg parasitoid from the native range of H. halys. Several parasitoids native to the U.S. were found to use H. halys eggs, but T. japonicus was not detected. In addition to the native egg parasitoids, a native sand wasp, Bicyrtes quadrifasciatus (Say), was observed to use Pentatomidae nymphs predominantly as prey for its larvae. Observations were made of female wasps provisioning nests with significantly more H. halys nymphs than native species. Additionally, sand wasp colonies could be artificially established in desired locations around farms, encouraging additional biological control agents in the surrounding field environment. Stand-alone methods like polyculture trap cropping or attract-and-kill methods can be used to manage H. halys with less reliance on insecticide sprays. In addition, monitoring field populations can be done passively with sticky-panel traps. Monitoring populations can aid in decision-making and gauge the effectiveness of other pest management strategies. Finally, T. japonicus has yet to be identified in Kentucky. However, native egg parasitoids and a native sand wasp are playing a role in reducing populations of the invasive H. halys and the impact they have on agriculture.

Digital Object Identifier (DOI)

https://doi.org/10.13023/etd.2022.351

Funding Information

United States Department of Agriculture - Specialty Crop Research Initiative (no.: 2016-51181-25409) 2017-2022

Southern Reginal Educational Board Doctoral Fellowship. 2020-2021

Available for download on Friday, August 09, 2024

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