Location: Pest Management Research
Project Number: 3032-22000-018-000-D
Project Type: In-House Appropriated
Start Date: Oct 1, 2015
End Date: Sep 30, 2020
Objective 1: Determine the role of rangeland insects, particularly grasshoppers and Mormon crickets, on rangeland ecosystem function and production. [NP304, Component 3, Problem Statements 3B1, 3B2] Subobjective 1.A: Identify the impacts of grasshopper herbivory and drought on rangeland function and nutrient cycling. Subobjective 1.B: Identify the competitive and predatory interactions between Mormon crickets and grasshoppers, their impacts on plant community composition and nutrient cycling on rangeland, and the effect of grasshopper abundance on Mormon cricket immunity to disease. Objective 2: Identify climatic and biotic ecological drivers of pest population dynamics (such as wheat stem sawflies, grasshoppers, and Mormon crickets) in order to develop practical predictive models of when these key pests will exceed economic thresholds. [NP304, Component 3, Problem Statements 3A1, 3B1, 3B2] Subobjective 2.A: Using long-term monitoring data, identify climatic and vegetation/landscape components that are associated with population shifts and variability of individual grasshopper species and grasshopper species diversity. Subobjective 2.B: Determine whether Mormon crickets have annual, biennial, and plurennial populations, and identify cues that cause females to lay eggs that break diapause and hatch after one, two, or several winters. Subobjective 2.C: Identify the role of moisture stress in breaking diapause and triggering Mormon cricket embryonic development. Subobjective 2.D: Identify climatic correlates of wheat stem sawfly and parasitoid wasp abundance and quantify the effects of precipitation on pest pressure, biological control and crop yield. Objective 3: Design sustainable approaches (e.g. roadside and conservation plantings, landscape diversification, rangeland fire, and grazing management) to manage key crop and rangeland insects, such as wheat stem sawfly, grasshoppers, and their natural enemies. [NP304, Component 3, Problem Statements 3A2, 3B2] Subobjective 3.A: Identify components of native vegetation that provide sugar resources for beneficial natural enemies, and assess the potential influence of these resources on natural enemy longevity and biological control. Subobjective 3.B: Identify components of rangeland management practices that can be used to sustainably manage grasshopper populations. Objective 4: Develop microbial control agents as tools for control of key rangeland and wheat pests [NP304, Component 3, Problem Statement 3A2, 3B2] Subobjective 4.A: Develop microbial control agents for grasshoppers and Mormon crickets. Subobjective 4.B: Determine the biological significance of endophytic Beauveria affecting wheat stem sawfly.
Grasshoppers, Mormon crickets and wheat stem sawfly are key constraints on rangeland and crop productivity. Grasshoppers and Mormon crickets consume ~$1.5 billion of forage annually and wheat stem sawfly causes ~$250-350 million in crop damage annually. Current control strategies for these major pests are inadequate, costly and/or result in unacceptable environmental impacts due to the historical reliance on broad spectrum insecticides. The goal of this proposed project is to acquire the knowledge needed to develop innovative, environmentally sound and sustainable management alternatives for control of these pests which currently lack sustainable control measures. To achieve this end, we will pursue research to broaden our ecological foundation, enhance prevention of pest outbreaks, and develop microbial intervention tools. We will develop a sound understanding of pest impacts on rangeland function and determine climatic and biotic drivers that cause these pervasive Great Plains pests to exceed economic thresholds. We will design sustainable habitat and landscape approaches to manage these pests and their natural enemies. We will develop microbial control agents to provide critically needed alternatives to pesticide-based control. Pursuing research along these themes of ecology, prevention and intervention will provide the foundational knowledge necessary to achieve the ultimate goal of developing ecologically-based and economically practical management strategies that reduce economic impacts and promote food security, while decreasing environmental impacts of control measures. We will communicate our results through on-going relationships with land management agencies, farmers and ranchers, academic societies, industry and state extension services.