Final report for GNC24-400
Project Information
Popillia japonica Newman (Coleoptera: Scarabaeidae), is an economically important pest of many crop and ornamental plants. The adult beetle is the most substantial defoliator of grape in the upper Midwest region. With alternative management options resulting in insufficient population reduction, current management practices rely on broadcast insecticide applications targeting adults on foliage, that are hazardous to the environment, non-target organisms, and farm workers. Perimeter-focused management targets the borders of crop plots for pest control with use of a killing agent, preventing incoming economically damaging insects from entering an interior. Attract-and-Kill (A&K) strengthens the edge-effect leveraged in perimeter-focused management by integrating the use of pest-specific, semiochemical attractant lures with the killing agent on a substrate. The objectives of this study were to assess the impact of A&K and Perimeter Spray applied to grape block perimeters on 1) P. japonica adult abundance and 2) grape foliar injury, compared to grower standard broadcast pesticide programs. In the A&K treatment, commercial lures were deployed along the perimeter of the plot. In the combined A&K and Perimeter Spray plots, a border application of Sevin XLR PLUS (carbaryl) was applied every 15-18 days. Grower Standard plots followed the pesticide schedule selected by each grower, typically involving one to four full‑block insecticide applications across the growing season. Across two growing seasons (2024-2025), beetle abundance and defoliation did not differ significantly among treatments. A&K and Perimeter Spray performed comparably to each other and to the grower standard while reducing treated surface area by 88% and application time by 78%, demonstrating that the Perimeter Spray provided the most cost-effective option with an 88% reduction in cost relative to the Grower Standard. Evaluating the potential of A&K and Perimeter Spray as reduced‑input management tools will help Wisconsin grape growers consider practices that maintain pest suppression while lowering environmental impacts, direct costs and reliance on broadcast applications.
Results of the project was presented to grape growers at the Growing Wisconsin Conference 2026 and Wisconsin Grape Growers field days. A survey was conducted to measure knowledge gained and interest in perimeter-based management. Understanding the effectiveness and potential to use this method of P. japonica control will provide Wisconsin vineyard growers with an alternative practice that would be cost effective and reduce environmental impacts while maintaining pest control within economic thresholds compared to conventional methods.
The expected action outcomes are 1) Wisconsin growers would be able to confidently implement A&K or Perimeter Spray alone methods into their management practices to effectively control P. japonica in their vineyards and 2) there is a reduction in the adverse consequences of conventional pesticide application through the implementation of A&K or Perimeter Spray management.
The learning outcomes of this project is to further grower knowledge of the importance of practicing environmentally sound agricultural practices and raise their awareness of cost-effective strategies to integrate those practices. Attract-and-Kill reduces dependence on insecticides through the use of pest-specific lures and decreases the impacts on non-target beneficial insects. Grower implementation of this strategy will achieve equivalent pest control levels as conventional means, as seen through yield measurements and defoliation reduction. Outcomes will be measured through post-study surveys at grower conferences to collect data from the vineyard community on their understanding and considerations for implementation of A&K or Perimeter Spray methods. A presentation conveying the results of the treatment comparison (Attract-and-Kill, Perimeter spray alone, and Grower Standard) will be given to audiences of Wisconsin vineyard growers at the Growing Wisconsin Conference and at grape field days.
Cooperators
Research
Study sites
This study was conducted at four commercial vineyards in 2024 and 2025 in south-central Wisconsin, USA. Each vineyard consisted of three plots (0.3-0.8 ha) of mature grapevines of mixed, cold-climate wine cultivars. The plots were at least 50 m apart to prevent lure overlap and insecticide drift between treatments. Management of other insects and diseases with minimal impact to P. japonica abundance was done at the discretion of each grower.
Experimental design
To assess the impact of the experimental management strategies on P. japonica abundance and foliar injury, a randomized complete block design, with block defined as three plots within one vineyard, was used to assign three grape plots to one of three treatments at each vineyard: 1) Attract-and-Kill (A&K), 2) Perimeter Spray alone, and 3) Grower Standard. The A&K treatment consisted of the deployment of commercially available P. japonica dual semiochemical lures (Trece: Adair, OK, USA) spaced every 12 m around the perimeter of the plot within the outside row of grapevines (Figure 1). The lures were suspended on the grape trellises 1.5 m off the ground using twist ties on 25 June in 2024 and 9 June in 2025 prior to beetle emergence (Henden & Guédot 2022). Lures remained deployed all season per manufacturer’s recommendation until the conclusion of the season. Since plot size was variable from 0.3-0.8 ha, the number of lures per plot in the A&K treatment varied between replicate plots (18 to 25 lures per plot). Due to the need to treat plot perimeters, two sites required forced randomization in treatment assignment as site limitations prevented tractor-mounted sprayers from being able to circumnavigate a plot. Growers were advised to begin treatment applications after observing more than 5 beetles near a deployed A&K lure on an edge row. The Perimeter Spray treatment only consisted of applying a perimeter-focused insecticide following the same schedule as the A&K treatment and did not include the deployment of lures. In the A&K and Perimeter Spray treatments, an insecticide spray of Sevin XLR PLUS (carbaryl) (IRAC 1A) at a rate of 2.34 L/ha, was applied every 15-18 days to account for weather patterns along the border row of each plot, dependent on P. japonica abundance. In 2024 applications for A&K and Perimeter Spray treatments began mid-July and in 2025 applications began early-July.
Because no economic threshold has been established for P. japonica in vineyards, insecticide applications under the Grower Standard treatment were made at the discretion of the grower and, when applied, were directed to the entire grape plot, spraying every row of the plot. Each vineyard manager maintained their own pest management practices within the Grower Standard control plot and all spray records were collected. In the event that P. japonica sampling counts exceeded 200 per experimental management plot, growers were able to apply a single broadcast application in all experimental treatment plots to reduce pest pressure.
1.1 Sampling of adult Popillia japonica
Popillia japonica adults were sampled from 15 June through 31 August in 2024, and 9 June through 25 August in 2025 to coincide with the peak adult activity in Wisconsin (Henden & Guédot 2022) and to avoid interference with crop harvest. Adult sampling occurred from all treatment plots weekly during daylight hours (0800 to 1700 h) under conditions of low wind and minimal precipitation. Within each plot, three interior rows of grapevines were randomly selected each week, and both sides of every vine along a 30 m long transect within these rows were examined for the presence of adult beetles (Figure 1). All adult beetles on the vines were hand-collected for storage in plastic bags. Beetles that escaped collection were recorded and included in the count data. Samples were stored frozen in the laboratory for counting.
1.2 Sampling of adult feeding injury
To assess defoliation, every week three randomly selected vines in each transect row used for beetle sampling were evaluated for leaf area loss by beetle herbivory (Figure 2) (Henden & Guédot 2022). Each vine sampled was avoided for resampling in later assessments. Alternated by week on a left or right cordon, 40 leaves were visually evaluated starting from the distal end of the first shoot towards the center of the vine. If 40 leaves were not available on the first shoot, the closest adjacent shoot was evaluated until 40 leaves were ranked. Leaves with damage not caused by P. japonica, such as those with phylloxera galls, tears or sunburning, were not counted in the 40 leaves. A metric scale of three categories of defoliation severity, i.e., 0% defoliation, 1-29% defoliation, and above 30% defoliation was used with a visual reference sheet to determine severity category of each leaf (Figure 3). The 30% threshold was determined as the level of vine defoliation that has been shown to result in a negative impact on vine growth and yield (Mercader & Isaacs 2003). Evaluators were trained to consistently categorize the leaves based on the visual reference sheet to ensure constancy throughout the summer to account for potential evaluator biases.
Statistical Analysis
Linear mixed‑effects models were used to evaluate adult P. japonica abundance and defoliation across treatments and sampling weeks in R (version 4.4.1). Fixed effects included treatment (A&K, Perimeter Spray, Grower Standard), sampling week (1-9 or 10), site (1-4), and their interactions, with plot (site × treatment) included as a random effect. Model assumptions were assessed using residual‑versus‑fitted and normal Q–Q plots. Beetle counts were analyzed on the ln(x + 0.1) scale, and defoliation was analyzed using ln(y + 0.1) or sqrt(y + 0.1) transformations in the 1-29% and ≥30% injury category, respectively. For 2024 beetle and defoliation analyses, Week 6 was removed due to a lack of representative data for all plots and models were weighted by the number of transects averaged per plot to account for data collection limitations. In 2025, the first two sampling weeks were excluded due to low beetle abundance representing pre-emergence, and Site D was removed due to a lack of continuous data. Type III ANOVAs with Satterthwaite’s approximation were used to evaluate fixed effects. Post‑hoc Tukey comparisons (R package: emmeans) were conducted when treatment effects were significant to assess pairwise differences among treatments and across weeks.
Economic analyses
To estimate the economic implications of adopting perimeter only insecticide applications relative to conventional broadcast sprays, treated surface area, spray time, and insecticide use were quantified under both approaches. A vineyard manager at Site A provided spray‑time estimates for a 0.55‑ha vineyard block, reporting that a perimeter spray required approximately 10 min while a broadcast application required approximately 45 min. These values were scaled to a per hectare basis using the proportion of the plot treated under each method.
Perimeter sprays were defined as treating the first vineyard row along the plot edge. For the 1 ha extrapolation, a 3 m perimeter band was used to represent the approximate width of one row. The treated area of a 3 m band around a 100 × 100 m vineyard was calculated as the difference between the full hectare and the interior area (94 × 94 m), yielding 0.12 ha of treated surface area.
Insecticide costs were calculated using a 2025 average price of $200 per 4‑L container ($50/L) of Sevin XLR Plus (carbaryl), based on prices obtained from three main agricultural suppliers (Militello Farm Supply, Keystone Pest Suspensions, and HSU Goring Supply). The label rate of 2.34 L/ha was used to determine the volume of insecticide required for broadcast and perimeter applications. Spray‑time reductions were estimated by scaling manager‑reported spray times to the proportion of the vineyard treated. Cost per lure was referenced from Great Lakes IPM at $4.50.
Popillia japonica Adult Abundance
The model that included treatment, sampling week, site, plots and their interactions as predictors for adult P. japonica counts showed no statistical difference among treatments in either year (2024: F₂,₆.₃₃₂ = 2.74, p = 0.139; 2025: F₂,₆ = 0.65, p = 0.555) (Figure 4). Abundance varied with sampling week in 2024 (F₇,₆₃.₇₅₅ = 4.45, p < 0.001) and 2025 (F₇,₆₃ = 11.38, p < 0.001). In 2024, Week 2 had significantly higher than Weeks 3–5, 7, and 9 (Tukey p = 0.0003–0.03). Week 9 had the lowest abundance and was significantly lower than Weeks 1–5 (Tukey p = 0.014–0.024). In 2025, abundance during Weeks 3–6 was significantly higher than Week 10 (Tukey p < 0.0001). In both years the Treatment × Week interaction was not significant (2024: F₁₄,₆₃.₇₃₉ = 0.38, p = 0.977; 2025: F₁₄,₆₃ = 0.62, p = 0.837). In 2024, site effects were not significant (F₃,₆.₃₅₁ = 1.31, p = 0.351). In 2025, adult abundance differed significantly among sites (F₃,₆ = 5.17, p = 0.042), with Site B having a lower abundance than Site E in the strongest pairwise contrast (Tukey p = 0.034), and no other pairwise comparisons among sites were significant.
Feeding Injury
The model that included treatment, sampling week, site, plots and their interactions as predictors for 1-29% injury counts did not have a main treatment effect in either year (2024: F₂,₆.₀₈₆ = 1.54, p = 0.288; 2025: F₂,₈ = 0.93, p = 0.433) (Figure 5). Defoliation in this severity category varied significantly across sampling weeks in both years (2024: F₇,₆₃.₂₁₀ = 3.56, p = 0.003; 2025: F₇,₈₄ = 12.82, p < 0.0001). In 2024, contrasts by Week showed that injury increased over the season, with Weeks 8–9 significantly higher than Week 2 (Tukey p = 0.0046–0.0055), while all other pairwise differences were non‑significant. In 2025, Week 3 had the lowest injury, with significantly higher levels from Weeks 5–10 (Tukey p < 0.01), while the remaining weeks did not differ appreciably from one another. Treatment × Week (2024: F14,₆₃.₂₁₀ = 0.99, p = 0.475; 2025: F14,₈₄ = 0.55, p = 0.894) and site (2024: F3,6.073 =2.63 , p = 0.114 ; 2025: F3,8 = 2.6319 , p = 0.278) effects were not significant.
The model that included treatment, sampling week, site, plots and their interactions as predictors for ≥30% injury counts showed a Treatment × Week interaction in 2024 (F₁₄,₆₉ = 1.98, p = 0.032) but not 2025 (F₁₄,84 = 0.5120, p = 0.920). A significant effect of treatment in 2024 (F₂,₆₉ = 8.75, p = 0.0004), but there was no effect in 2025 (F₂,₈ = 1.29, p = 0.327) (Figure 6). A Tukey post‑hoc test indicated that treatment differences in 2024 occurred only in four weeks, with the largest separation in Week 5 where A&K was significantly higher than GS (p = 0.0061), followed by separation in Weeks 7–9 where Perimeter Spray was significantly higher than the Grower Standard (p = 0.004–0.016). Week effects were significant in both years (2024: F₇,₆₉ = 8.73, p < 0.0001; 2025: F₇,₈₄ = 6.96, p < 0.0001). In 2024, Weeks 7–9 had significantly higher defoliation counts than Weeks 1–3 (Tukey p = 0.005–<0.0001), and Week 9 showed the highest injury overall, differing strongly from Weeks 1–5 (p = 0.0008–<0.0001). Across 2025 weeks, injury was lowest in Week 3 and significantly higher in all subsequent weeks (Weeks 4–10; Tukey p = 0.14–<0.0001). Site effects also had significant influence on ≥30% injury counts (2024: F₃,₆₉ = 3.04, p = 0.035; 2025: F₄,₈ = 9.15, p = 0.004), however Tukey‑adjusted pairwise comparisons did not identify any statistically distinct site pairs in 2024. In 2025, contrast occurred between Site B and Site E, where Site B had lower injury (Tukey p = 0.056); all other pairwise site comparisons were non‑significant.
Discussion
This study investigated perimeter-based management on P. japonica abundance and defoliation compared to broadcast insecticide applications in vineyards. The results show that an A&K or Perimeter Spray program can be implemented at a plot scale with equivalent levels of control to the grower standard of broadcast applications, with up to four applications per season, to manage adult population abundance. Defoliation, evaluated by counts of three injury categories (0%, 1-29% and ≥30%), showed no consistent treatment separations, and counts in the ≥30% category were uniformly low, limiting both statistical and practical distinctions among treatments. In addition, the border-focused treatments, i.e., A&K and Perimeter Spray, reduced sprayed surface area of a one ha plot by 88% when compared to a broadcast application.
Since the introduction and dispersal of P. japonica in US agricultural systems, management standards have relied on broadcast applications of insecticides due to their effectiveness and affordability (Althoff & Rice 2022). Here, there was no difference in beetle abundance between the A&K, Perimeter Spray, and Grower Standard treatments in either year. Attract-and-Kill was assessed against P. japonica and showed similar results with prior work under low to moderate pressure. Lannan & Guédot (2024) found equivalent control to the grower standard in 0.2 ha vineyard plots, spraying point‑source vines rather than the perimeter applications used here. Paoli et al. (2023) demonstrated strong early-season control with A&K stations using insecticide‑treated netting, but mortality declined as residues degraded, and beetle residence times on stations (75–95 s) could have impacted mortality rates. This study highlights a design trade‑off of replacing netting to maintain lethal residues every 30 to 40 days versus applying an insecticide every 15 to 18 days to sustain an effective perimeter. Together, the evidence suggests that A&K can reduce inputs relative to broadcast applications, but its effectiveness depends on residual longevity, and insect retention. In other study systems A&K has been reported to reduce pest abundance and crop injury with H. halys in apple orchards (Morrison et al. 2019), D. suzukii in berry crops (Klick et al. 2019) Ceratitis capitata Wiedemann (Diptera: Tephritidae) in peach (Hafsi et al. 2016). Conventional standards of control were not achieved when testing spinosad containing spheres to attract Delia antiqua Meigen (Diptera: Anthomyiidae) in onions (Willett et al.2020), but it did reduce some damage when where other options are not available or when used as an additional tool. With A&K, lure‑driven aggregation can elevate local feeding pressure when killing agents are insufficient. For example, with H. halys, A&K stations attracted more adults than they killed, a risk highlighting the importance of matching lure strength with insecticide persistence (Masetti et al. 2024). Use of carbaryl in border focused applications maintained the same level of adult P. japonica suppression in interior vines as the Grower Standard, indicating that the killing agent remained equally effective while substantially reducing the total area treated with insecticide (Vitullo & Sadof 2007).
Edge-driven insects enter vineyards from the surrounding landscape and accumulate along border rows. Perimeter applications exploit this inherent spatial pattern, functioning similarly to lure‑based systems by focusing control where some insects naturally aggregate. A perimeter spray without lure deployment reduces labor inputs and cost while maintaining the same level of control. Here, perimeter sprays resulted in similar levels of control compared with A&K and broadcast sprays. Perimeter applications target border aggregations by intercepting beetles before they reach interior rows, a pattern consistent with the edge-driven colonization behavior of P. japonica (Vitullo & Sadof 2007; Sara et al. 2013; Henden & Guédot 2022). This outcome was observed in reduced insecticide programs for D. suzukii (Klick et al. 2016; 2019) and Conotrachelus nenuphar Herbst (Coleoptera: Curculionidae) (Chouinard et al. 1992) where simplified sprays provided economically acceptable levels of control. Similarly, Trimble and Vickers (2000) found border sprays successfully prevented damage from the target pests, Cydia pomonella Linnaeus (Lepidoptera: Tortricidae) and Rhagoletis pomonella Walsh (Diptera: Tephritidae), in apple orchards. However, this approach increased orchard vulnerability to the secondary pest Choristoneura rosaceana Harris (Lepidoptera: Tortricidae), where leafroller injury was significantly greater in perimeter spray plots than in broadcast plots. These contrasting responses from primary and secondary pests show that the success of reduced-input perimeter strategies is closely tied to the spatial ecology of the insect species targeted. The elevated ≥30% defoliation observed in Week 5 of 2024 for A&K relative to the Grower Standard, and in Weeks 7–9 for Perimeter Spray, may indicate missing spray windows that can allow defoliation to accumulate, demonstrating the importance of well-timed interventions that prevent beetles from entering vineyard plot interiors. Eliminating the need to artificially attract beetles with lures avoids the risk of over attracting, a common issue in P. japonica mass trapping (Piñero & Dudenhoeffer 2018). As the primary defoliator of grape, P. japonica is the main, and in some vineyards the only, insect pest that spray programs are designed to suppress (Hammons et al. 2010). Its tendency to concentrate along vineyard edges mirrors the behavior of C. nenuphar, reinforcing the suitability of perimeter spray as an effective reduced input option. A similar behavioral phenomenon is exploited in trap cropping where a border of preferential host crops is planted to mimic edge driven colonization and prompt flight arrestment of target insects before reaching cash crops (Boucher et al. 2003; Tillman et al. 2012).
Aggregations of P. japonica on grapevines have the capability to defoliate a large proportion of leaves, reducing photosynthetic potential and impacting fruit quality. Across both years, treatment effects on defoliation were minimal, reflecting the biologically inconsequential effects of high‑severity feeding events under low to moderate pest pressure. Grapevines have a strong capacity to tolerate moderate injury (Mercader & Isaacs 2003); however, injury above 30% is more likely to have long-term effects on vine growth, including reduced cold hardiness of primary buds (Hammons et al. 2010) and potential impact on fruit quality (Ebbenga et al. 2022). Here, two levels of injury are assessed, 1–29% and ≥30%, reflecting the threshold transition from physiologically tolerable to potentially impactful to vine growth and fruit development among treatments. At the 1-29% injury category, incidences of defoliation remained low to moderate, and no treatment differences were detected in either year. At this lower severity level, vines can buffer minor losses, especially during the middle and later parts of the season (Mercader & Isaacs 2003), mimicking canopy pruning management practices recommended to increase light exposure to fruit (Feng et al. 2015), beneficially alter fruit composition (Hickey & Wolf 2018; Riesterer-Loper et al. 2019) and balance growth in vigorous vines (Intrigliolo et al. 2014). With the ≥30% injury rating, occurrences were low across sites and treatment differences occurred only in isolated weeks in 2024 only. These brief separations likely reflect localized gregarious feeding events rather than consistent effects of any management strategy, especially considering the low pest pressure.
Treatment effects on P. japonica abundance and feeding injury remained insignificant when populations reached low to moderate pressure. In 2024, abundance at most sites did not trigger vineyard-specific pest management, as indicated by only one vineyard applying four applications of insecticide in the Grower Standard plot, while no other Grower Standard plots received management in other participating vineyards. In 2025, abundance reached moderate pressure at 50% of sites where growers applied broadcast applications in Grower Standard plots. This demonstrates the density dependent nature of applying treatments based on abundance and foliar injury rather than a predetermined calendar schedule. The levels of pest pressure reflected in this study does not represent outbreak years, when adult densities grow rapidly and persistently. Under such conditions, continual immigration and rapid aggregation can overwhelm perimeter focused suppression (Potting & Powell 2005), making broadcast applications necessary to prevent economic injury (Rahman & Broughton 2016; Nixon et al. 2022). This was evident at Site E in 2025, where sustained influx from surrounding habitats pushed adult abundance above management levels despite perimeter interception, reflecting density dependence of reduced-input management success and the importance of continual monitoring. Broadcast applications remain a relevant component of vineyard integrated pest management when populations experience high pressure outbreaks (Trimble & Vickers 2000).
Both border-focused insecticide treatments, A&K and Perimeter Spray, reduced insecticide use by 88%, and application time by 78% relative to broadcast sprays. Perimeter Spray reduces insecticide cost per hectare and application by 88% or $103 when compared to one broadcast spray at the same label rate. These metrics represent substantial labor and input cost savings for growers and could replace a broadcast application when abundance exceeds grower-decided management thresholds under moderate pest pressure. Economic feasibility was found to be a drawback when A&K was compared to Grower Standard for H. halys in apple, where the cost of expensive experimental lures exceeded the cost of a conventional spray program when considering direct, up-front costs and additional revenue from improved fruit quality (Morrison et al. 2019). In contrast, given the direct costs of commercially available P. japonica lures and insecticide use per ha, A&K in this study reached cost reductions, compared to the grower standard, after the first application and only increased by $157 compared to the cost of a perimeter spray alone. The A&K and Perimeter Spray methods align with broader industry movement toward reduced input and targeted insecticide programs driven by regulatory pressure, environmental stewardship, and increasing consumer interest (Boucher et al. 2003; Pertot et al. 2017; Fouillet et al. 2022).
Educational & Outreach Activities
Participation summary:
The results of the pre- and post- survey are as follows:
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There was an increase in the perception of effectiveness of PS and AK from pre to post survey, PS receiving more votes than AK by 17% in 2026. Decrease in percentage of participants choosing full block by 43%.
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Increase in interest in AK (would consider or highly interested), 44% in 2025 and 63% in 2026.
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Increase in interest in PS (would consider or highly interested), 50% in 2025 and 64% in 2026. Smaller than the increase difference of AK.
- Factors that influence decision to implement A&K in their vineyard to manage Japanese Beetle:
- Integration with current pest management (10 votes)
- Proven efficacy (10 votes)
- Cost (8 votes)
- Environmental impact (6 votes)
- Recommendations of experts (6 votes)
- Peer usage (3 votes)
- Resource Availability (2 votes)
Project Outcomes
A clear impact to agricultural sustainability is the quantity of chemical inputs used on the land. Compared to conventional full-block applications, both attract-and-kill and Perimeter Spray techniques greatly reduce the inputs of insecticide in a vineyard. Using application information from Site A, a 3 m perimeter spray applied to a 1 ha vineyard plot was estimated to treat 0.12 ha of the plot, leaving 88% of the plot unsprayed. Using the label rate of 2.34 L/ha, the perimeter application required 0.28 L of insecticide and cost $14, compared with 2.34 L and $117 for a broadcast spray. This represents an 88% reduction in treated area and an 88% reduction in insecticide use and cost for Perimeter Spray. Deploying lures at 12 m intervals around a 1 ha plot requires 34 lures, costing $157 per season. After the first application, A&K becomes cheaper per hectare than repeated broadcast sprays, even after accounting for baseline lure costs. Grower reported spray time estimates indicated that perimeter applications for either reduced-input treatments required approximately 18 min/ha, compared with 82 min/ha for conventional broadcast sprays, an overall reduction of 78% in application time. This reduces labor, and increases applicator safety and environmental benefit through the potential for less non-target impacts.
Our understanding of sustainable insect management deepened substantially over the course of this project, particularly regarding how reduced‑input strategies can be evaluated, validated, and communicated to growers. We entered with a general expectation that both Attract-and-Kill and Perimeter Spray were reduced‑input options used in other cropping systems. This project strengthened my technical and analytical skills in several interconnected ways. We refined our experimental design abilities by coordinating multi‑site field trials and standardizing treatments across variable vineyard environments, which required careful planning and consistent implementation. My statistical skills deepened as we used mixed‑model analyses to evaluate treatment performance under real‑world variability. We also developed an understanding of cost and labor efficiency, which became essential for comparing the practical sustainability of Attract-and-Kill versus Perimeter Spray. Finally, my science communication skills grew as we translated complex behavioral ecology and reduced‑input IPM concepts into clear, actionable recommendations for growers.
The high operational efficiency of the Perimeter Spray treatment, together with the elimination of lure related deployment, upkeep, and over attraction risks, may enhance its appeal for grower adoption when compared with A&K management. Perimeter focused techniques are viewed as simple to apply and offer several additional advantages related to worker safety, marketing, environmental drift (Boucher et al. 2003; Deng et al. 2025) and reduction of nontarget species impact (El-Sayed et al. 2009; Biddinger et al. 2014). Behavioral considerations that may influence the efficacy of pest interception include colonization process, within and between field movement and host-plant searching mechanisms (Potting & Powell 2005), factors that align with P. japonica behavior (Henden & Guédot 2024). Overall, site level variation and seasonal phenology exerted strong influences on beetle abundance and injury in this study, indicating that management decisions need to account for abiotic factors affecting abundance and landscape context (Rusch et al. 2013). These findings support integrating reduced input, perimeter-based techniques for P. Japonica management in vineyards for their cost effectiveness and operational efficiency while emphasizing the contextual specificity that must be considered when implementing behavioral management approaches.