Spatial Patterns and Sequential Sampling Plans for Estimating Densities of Stink Bugs (Hemiptera: Pentatomidae) in Soybean in the North Central Region of the United States

Abstract

Stink bugs are an emerging threat to soybean (Fabales: Fabaceae) in the North Central Region of the United States. Consequently, region-specific scouting recommendations for stink bugs are needed. The aim of this study was to characterize the spatial pattern and to develop sampling plans to estimate stink bug population density in soybean fields. In 2016 and 2017, 125 fields distributed across nine states were sampled using sweep nets. Regression analyses were used to determine the effects of stink bug species [Chinavia hilaris (Say) (Hemiptera: Pentatomidae) and Euschistus spp. (Hemiptera: Pentatomidae)], life stages (nymphs and adults), and field locations (edge and interior) on spatial pattern as represented by variance–mean relationships. Results showed that stink bugs were aggregated. Sequential sampling plans were developed for each combination of species, life stage, and location and for all the data combined. Results for required sample size showed that an average of 40–42 sample units (sets of 25 sweeps) would be necessary to achieve a precision of 0.25 for stink bug densities commonly encountered across the region. However, based on the observed geographic gradient of stink bug densities, more practical sample sizes (5–10 sample units) may be sufficient in states in the southeastern part of the region, whereas impractical sample sizes (>100 sample units) may be required in the northwestern part of the region. Our findings provide research-based sampling recommendations for estimating densities of these emerging pests in soybean.

Sampling Optimization and Crop Interface Effects on Lygus lineolaris Populations in Southeastern USA Cotton

“…In this study, defined sampling quadrants explained the second-highest level of variability in L. lineolaris densities, suggesting a non-random, aggregated spatial distribution within fields. This result is not surprising, given previous work suggesting non-random, clustered distributions of closely related Lygus species in cotton [51,52] and other heteropteran species in field crop production systems [53][54][55][56]. In addition to field-specific scouting, intensive L. lineolaris sampling within fields is likely important to minimize the probability of false negative or positive assessments when making management decisions using economic thresholds.…”

Assessment of Injury by Four Major Pests in Soybean Plants Using Hyperspectral Proximal Imaging

“…Outbreaks of the main soybean pests occur in nonuniform spatial distributions [20]. The spatial distribution is characterized as aggregating for species of the complex of defoliating caterpillars [37,38] and stink bugs [39,40]. In addition, pest inspection using beat-cloth is still currently being used as a traditional sampling method in soybean crops.…”

Population density, spatial patterns and sample size of Edessa meditabunda (F., 1794) (Hemiptera: Pentatomidae) on alternative plants during soybean off-season in southern Brazil

“…When determining the minimum number of plants to be sampled, there was a high variation between the different degrees of precision adopted. This variability depends in theory on the population density present, in an inverse relationship, that is, the higher the population density the smaller the number of samples needed to estimate the population (Arbab 2014;Pezzini et al 2019). In ecology studies in which degrees of accuracy between 90 and 95% are adopted, a large number of samples were observed, making labor expensive.…”

“…The determination of stink bugs spatial distribution patterns can help in building located sampling plans and management, increasing efficiency and reducing costs and environmental impact during management (Reay-Jones 2014). To define the spatial of insects several indexes of dispersion and frequencies distribution are used (Pezzini et al 2019). The confirmation of the type of insect distribution in an area occurs only with the knowledge of the probabilistic models that describe the frequency distributions of the numbers of individuals of the studied insect (Souza et al 2013).…”