Performing Department
(N/A)
Non Technical Summary
This project aims to survey stink bugs and beneficial arthropods in North Carolina soybeans. The threat of stink bug damage to soybean production has been increasing over the past several years. Drivers of these changes may relate to warming climate and changing agroecosystem structure. Currently, we do not understand how stink bug species vary at the field, farm, or regional level. We do know that problematic southern species (red banded, southern green) are expanding their overwintering range northward into the Carolinas. Moreover, changes in natural enemy communities may also have effects on biological control services in soybean systems. The last comprehensive stink bug survey in North Carolina soybean was conducted in the 1970s and this data provides a foundation for this study. The goal will be to generate new baseline data to understand how species ranges are changing in response to a changing climate, landscape, and agronomic practices. North Carolina is an ideal location for climate research because we are currently experiencing species shifts. This is important because chaning distributions in the southeastern U.S. may be an indicator for future changes in northern soybean agroecosystems.
Animal Health Component
40%
Research Effort Categories
Basic
60%
Applied
40%
Developmental
0%
Goals / Objectives
Specific project objectives are:1) To compare historic and contemporary soybean arthropod communities by sampling the same fields with identical methodology.2) To conduct a statewide survey of stink bug communities in soybean and relate diversity to landscape and climate.3) To quantify biological control services for stink bugs between two soybean planting dates in each of the three North Carolina physiographic regions (Mountains, Piedmont, Coastal Plain).
Project Methods
This research project having the following objectives, the proposed research will develop fundamental knowledge about stink bug and natural enemy diversity in soybean agroecosystems. Our proposal is specifically focused on filling knowledge gaps in the southeast U.S. soybean system, however, results likely represent similar trends that exist in many row crops where stink bugs are a persistent problem. Below are the specific objectives, location where research will be conducted, and context for the question.Specific project objectives are:1) To compare historic and contemporary soybean arthropod communities by sampling the same fields with identical methodology.2) To conduct a statewide survey of stink bug communities in soybean and relate diversity to landscape and climate.3) To quantify biological control services for stink bugs between two soybean planting dates in each of the three North Carolina physiographic regions (Mountains, Piedmont, Coastal Plain).Objective 1 (On-Farm): The goal of Objective 1 will be to enumerate arthropods collected from the soybean canopy using the same sampling methodology as the Effects of Agroecosystem Structures on the Population Dynamics of Selected Arthropods project. We will leverage relationships with independent crop consultants and NC Cooperative Extension Agents to identify landowners that currently farm these fields.We hypothesize that landscape simplification over the past five decades will favor pests that occupy broad ecological niches when compared to natural enemies that have a closer association to non-crop habitats that are now absent (e.g., hedgerows, weedy fields). We will regress species diversity and abundance against differences in landscape structure between ~1980 and 2025/2026. To do this, we will use climate data in conjunction with historical aerial photography to document attributes of field and landscape structure that correspond to known sampling locations. The outcomes of Objective 1 will inform spatially explicit deliverables that characterize soybean arthropod community shifts across five decades of change to agricultural production systems.Objective 2 (On-Farm): The goal of Objective 2 will be to measure abundance of stink bug species in soybean from the mountains to the coast. The focus of this objective is narrowed to stink bugs alone, allowing for a far greater number of candidate fields and samples nested within field. We will use physiographic region to document differences in species composition that are likely driven by a changing climate, particularly lessening minimum winter temperatures that will enable the expansion of southern green stink bug into more habitats at higher elevations.We hypothesize that the abundance of stink bug species will be heterogeneous across the state with clear linkages to environmental conditions that limit their ranges. We assume that temperate invasive species (i.e., Brown Marmorated Stink Bug) will be more prevalent in mountain fields which is supported by previous data (Bakken et al. 2015). In contrast, southern green stink bug will continue to be limited by winter temperatures and will be restricted to southern tier counties in NC. This objective builds on two years of NC Soybean Producers Association funding that generated preliminary data from 64 commercial soybean fields distributed across the state. Species catch varies considerably across physiographic regions and fields nested with region. This variation highlights the probable role of unique local landscape factors driving species abundance nested within each region. Additional fields will be sampled in the proposed objective to uniformly represent each of the state's three physiographic regions to understand climatic and landscape factors driving stink bug variation. Stink bug abundance and diversity will regressed against surrounding landscape composition, elevation, and climatic variables. Applied results of this work will inform growers about the prevalence of specific species that have unequal response to common pyrethroid insecticides used for their control. Basic knowledge will characterize climate and landscape factors that relate to soybean infestations along an elevational gradient.Objective 3 (Research Station - Large Plots): Soybean planting windows have broadened significantly during the past several decades. This agronomic change in combination with climate may result in asynchrony between natural enemies and stink bug species they control. To document this potential effect, we will use natural enemy sampling and sentinel stink bug egg masses to determine if predation and parasitism rates are equivalent across three physiographic regions. Because sweep sampling for parasitoid adults is inefficient, we will also use timed vacuum sampling to assess abundance.We hypothesize that stink bug eggs deployed in very early soybean planting will have less predation when compared to later season plantings due to pest and predator asynchrony. Moreover, we hypothesize that there will be a significant interaction between planting date and physiographic region.We assume equivalent predation rates among planting dates in the warmer coastal plain and significant differences in cooler mountain production systems. Objective outcomes will document the diversity of biological control agents in space and time. Results will be related to stink bug scouting data in these large plots to characterize temporal synchrony of pests and natural enemies.