Development and implementation of a trap cropping system to suppress stink bugs in the southern Coastal Plain

Final Report for OS06-029

Project Type: On-Farm Research
Funds awarded in 2006: $15,000.00
Projected End Date: 12/31/2008
Region: Southern
State: Florida
Principal Investigator:
Dr. Russell Mizell, III
NFREC-Quincy, University of Florida
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Project Information

Abstract:

A trap cropping system was developed to manage the stink and leaffooted bug pests in the coastal plain and perhaps other areas. The biologically-based strategy can be customized for any planting season from spring to fall and is farmer-philosophy and farm-scale neutral. Plantings are established using standard cultural practices. A mixture of species is required to ensure continuous optimum food availability in the trap crop to out compete the cash crop for stink bug feeding. Triticale, sorghum, millet, buckwheat, and sunflower are the main species recommended. Small-acreage growers may wish to plant trap crops in large containers for portability.

Introduction

Stink bugs are an overarching pest management issue in all types of agriculture in the Southeast. Stink bugs, primarily the brown stink bug, Euschistus servus (Say), the dusky stink bug, E. tristigmus (Say), the green stink bug, Acrosternum hilare (Say) and the southern green stink bug, Nezara viridula (L.) and the leaffooted bug, Leptoglossus phyllopus (L.) are direct primary pests of vegetable, fruit, seed and grain crops in the Southeast regardless of the production system (Schaefer and Panizzi 2000). McPherson and McPherson (2000) reported that 21 important commodities in the U.S. were damaged by stink bugs. In Georgia, during some years, stink bug damage in soybeans alone was estimated to cost producers over $13 mil in damage and control costs (Douce and McPherson 1991).
Stink bugs are naturally tolerant of many pesticides; therefore, few efficacious insecticides are available to manage these difficult pests. Virtually no biologically-based strategies and tactics of practical use are recommended to suppress most stink bugs in small farm, organic or homeowner production. Stink bugs are also major pests in commercial agronomic, fruit and vegetable crops: beans, peas, okra, small grains, soybean, cotton, peach and pecan, etc. The boll weevil eradication program and the use of GMO cotton for lepidopteran pest suppression have greatly reduced the pesticide load in commercial cotton. As a result, stink bugs have recently become major pests in cotton. Based on the large acreage of cotton planted across the Southeast, the vagility of stinkbugs and the temporal and spatial population dynamics at the landscape level of these pests (Mizell et al. 2003, unpublished GIS data), it is logical to assume that losses from stink bugs will continue to increase in the susceptible crops.
The primarily goal of this project was to refine and demonstrate a trap cropping system to manage the three major stink bug pests, E. servus, A. hilare, and N. viridula, as well as other minor stink bug species (in the genera Banasa, Thyanta) and the leaffooted bug (L. phyllopus) in vegetable and fruit production in the southern coastal plain. The biologically-based, integrated strategy was customized for the spring to fall planting seasons. Briefly, we used a series of preferred host plants that attract and concentrate the stink bugs and their natural enemies in the trap crop instead of the cash crop, enabling population suppression by mechanical removal or other means, and thereby reducing the damage in the cash crop.

Project Objectives:

Objective 1. To refine and demonstrate a trap cropping system for stink bug management that is widely adaptable in the southern coastal plain.
Objective 2. To establish an effective outreach program to deliver the information to clientele.

Research

Materials and methods:

Plantings of the test trap crop species were developed and evaluated in a number of ways over the course of this study. The main demonstrations were conducted on the NFREC-Quincy property as the off-farm cooperators were unable to sustain crops during the years of the project due to weather and other problems. However, we were able to educate many more people through normal Center outreach programs such as field days and other programs by having the main demonstration plots at the Center.
Our original plan was to use long-juvenile soybeans combined with buckwheat and sunflower, however, the soybeans were destroyed quickly in early testing either by deer or defoliating Lepidoptera. Therefore, we changed plans by incorporating plant species that would be less attractive or more tolerant to deer, have seed commercially available to producers, and be attractive to as many of the major stink and leaffooted pests as possible.
Four types of plot evaluations were undertaken: 1 and 2). In 2006 and 2007, we set up late spring plantings and also a mid summer planting in 2007 of the test trap crops with 4 replications in a randomized complete block design. Plot size was 2 x 10m. Plant species were established using standard agronomic culture and management practices along with overhead irrigation as needed. Treatments for evaluation consisted of buckwheat (cv Mancan), grain sorghum (cv 9200Y), pearl millet (Tiftleaf III), sunflower (Perodovic), okra (Clemson Spineless) and hemp sesbania (cv from Adams-Briscoe Seed Co) along with an unplanted weedy control plot. The plots were visually inspected 2-3 times per week for the plant growth stage present and one time per week by sweep net (3 sweeps/plot) for stink/leaffooted bugs and beneficial insects. Once seed heads began to form and stink or leaffooted bugs appeared, we gathered separate data to establish the relationship of plant growth stage to stink bug feeding for each plant growth stage by observing a100 insects per stink bug species and bug life stage present (Fig. 1). The phenology of the plants in the plots was followed until maturity of each species and plot. Following maturity, each plot was ratooned (mowed down) to 0.5m in height and the plant and insect observations continued until plants either died or no longer attracted bugs. This experimental design was followed in both 2006 and 2007. However, several late March freezes and accompanying lower soil temperatures in 2007 killed or substantially impacted (leaf damage or retarded growth) the spring plots necessitating replanting.
3). The freeze occurrence prompted us to search for a plant species more suitable for early spring weather. Serendipitously, we were able to examine a large triticale cultivar selection trial for susceptibility and attraction to stink and leaffooted bugs being conducted by colleagues at NFREC-Quincy. During the course of these observations, we discovered that triticale attracted all four of the target bug species in early spring (March-April) long before any of the other test species could be available. Therefore, in fall (October) 2007, we established 3 plantings (staggered in time by two weeks beginning on 2 October) in 2x10m plots of triticale (cvs Monark and 342, Foundation Seed, Marianna, FL). These two cultivars vary in maturity by ~10 days (Monark after 342). In spring 2008, we sampled the plots beginning in mid February as described above. Late freezes in North Florida destroyed the heads from the two earliest plantings, however, the last October planting developed heads (first bloom stage) naturally and began attracting leaffooted bugs on 10 March and other bug species as they emerged from overwintering.
4). In summer, 21 July 2006, we planted additional plots of the test species as described under planting one above in replicated plots (n=3) on the east perimeter of a 0.35 ha (100 x 35m east-west) planting of Hinson soybeans in an organic production trial. Beginning when the plants were ~ 0.23m in height, the plots were sampled once each week as described above. The soybeans were also sampled using a sweep net (n=3 sweeps) at 1 and 3 m away from the trap crops adjacent to each plot replicate. Stink bugs present in the soybean sweep samples were recorded by life stage (Figure 3).

Research results and discussion:

A trap cropping system for stink bug management.
We developed a trap cropping system that is neutral with respect to farm scale and farmer philosophy. Therefore, it is usable by conventional growers as well homeowners, organic and other types of small-acreage producers. Small-acreage producers and home owners also have the option of growing the trap crops in large portable containers to reduce establishment costs and increase the efficacy of the tactic by strategic placement of the trap plants adjacent to a sequence of cash crops.
Hemp sesbania did not attract stink bugs of any species well enough to recommend. Okra did attract green stink bugs and consistently was infested with aphids that attracted large numbers of syrphid flies, ladybeetles and other generalist beneficial species. However, we do not recommend okra as part of a stink bug trap crop system because it matures slowly, is difficult to manage due to harvesting needs and often supports phytophagous soil nematodes.
Description of the trap cropping procedure: All species used in the trap crop system are established using standard culture and management practices. Each species offers certain individual food and visual/odor characteristics that are attractive to the four major stink/leaffooted bug species (hereafter stink bugs) previously mentioned. Stink bugs are highly polyphagous feeders and move through the landscape in search of food and oviposition plants whose qualities vary over time and space. Polyphagy is an apparent manifestation of the stringent requirements stink bugs have for food quality (Fig.s 1 and 2). All four of the major stink bugs and likely all species are very finicky with respect to plant growth stage as it relates to the quality of their food. The state of the preferred food relative to plant growth stage, which we established as part of this study, also varies by stink bug life stage, with nymphs and adults different (Fig. 1). Because of this food quality issue, a narrow window exists for each plant to serve as food for stink bugs. This is critically important because it is necessary to provide a continuous source of high quality food in the trap crop to prevent stink bugs in the cash crop which is at some point also very favorable for stink bug feeding. Thus, the reason why trap crops require multiple plant species is to maintain a continuously competitive food source to out compete the cash crop for stink bug feeding.
To minimize the number of plant species used in a trap crop, it is also necessary to identify species that are attractive, acceptable hosts to as many stink bug species as possible. Prior to this study, host plants that were attractive to both the major stink bug species and to the leaffooted bugs were not well known. In addition, it is necessary to have the trap crop plants available in a high quality state prior, during, and after the cash crop is most susceptible to bug feeding and damage. Lastly, plant species, and their cultivars in the case of food or grain crops, have individual growth characteristics such as maturity date, plant height, and seed head structure, as well as specific requirements for and tolerances to soil, moisture and other habitat factors. These not only determine culture and management practices, but they also may affect stink bug behavior either positively or negatively. For example, sorghum and millet do not germinate and grow well under cool soil conditions, whereas cool conditions are ideal for triticale. Buckwheat matures seed in 3-5 weeks, whereas sorghum and millet may require 60-90 days. Stink bugs appear to respond better to (arrest in the plots) taller plant species and prefer relatively open seed heads.
Presented with these requirements of food quality, multiple target pest species and optimum timing and practicality, along with the inherit limitations of insect behavior and the growth, culture and management of each plant species, we tested a number of plant species and make the following recommendations. These recommendations cover the entire season from spring to summer to fall, attract all of the major stink bug pest species, and many if not most of the minor species, and present a workable plan to suppress stink bugs under any farming philosophy and farm size. While beyond the scope of the project, the plants recommended for trap crops from this study are also very useful for augmentation of beneficial insects, e.g., parasites and predators of stink bugs, as well as many generalist feeders, and for augmentation of pollinating bees and wasps. These factors are attributable to the presence of flowers with their nectar and pollen and the occurrence of aphids and other phytophagous insects on the trap crop plants which may produce honeydew or serve as alternate hosts for beneficials.
For early spring cash crops, we recommend that plantings of triticale be made in fall by staggering several planting dates in October to early November (should be customized to location); earlier plantings may be more effective in more northern locations. Several cultivars may be established to provide a range in plant height (we believe that taller varieties better attract the stink bugs) and maturity dates. Crimson clover and hairy vetch may also be planted at the same time within the plots to augment beneficials in spring. Triticale surmounts the limitations of cool spring soil conditions that prohibit growth of sorghum and millet and the staggered plantings will provide a hedge against total loss of the trap crop from unpredictable spring freezes. The range in maturity dates provided through use of multiple cultivars will prolong the efficacy of the trap crop and insure timely competition with the cash crop relative to food quality. Because sunflower and buckwheat can withstand cooler soil temperatures, these two species can be added to the spring trap crop in early spring. Note that neither buckwheat nor sunflower is totally immune to spring frosts. However, buckwheat is highly important due to its rapid seed formation within 3-5 weeks from planting. Because of this, if planted repeatedly, buckwheat may serve as a “relay” crop between the maturation dates of the other species.
For the summer to fall period, sunflower, buckwheat, sorghum and millet are recommended species for the trap crop. Okra may also be added to further attract stink bugs and enhance the augmentation of beneficial insects; however, all of the other plant species recommended along with augmentation of pollinators perform the same functions. For sorghum and millet, we recommend planting several commercially available cultivars with a range in maturity dates. Sorghum and millet also are amenable to ratooning, i.e., mowing, to increase their temporal efficacy.
Sorghum seed heads remain in the optimum growth stage that is most attractive to stink bugs for a period of 2-4 weeks depending on the weather, cultivar and cumulative bug feeding damage. Ratooning of sorghum works best if the plants are mowed (bush hogged) to a height between 0.5-0.75m after the initially-formed, mature seed heads are no longer attractive to stink bugs. The ratooned plants will tiller (develop multiple stalks) and will set new heads in about 3-4 weeks. However, the plants will be shorter in height and out of synchrony with respect to seed formation; unlike the synchronize seed set derived from the initial seed plot establishment. This is an important and unexpected attribute or “emergent property” that is very useful to extend the temporal efficacy of the trap crop. Millet may also be ratooned, but it does not return seed set as well nor grow as tall as sorghum. Sunflower is not amenable to ratooning while buckwheat is. However, buckwheat is so easily planted and quick to form seed heads that ratooning may be the less desirable management choice. Okra is also amenable to ratooning but requires longer time periods to mature.
All of the recommended species may be cultivated in large containers individually or in multiple species groups for portability and moved around to small plantings in a strategic approach by small-acreage producers or homeowners. Container plants can be ratooned as well.
Trap crop spatial and temporal considerations: Stink bugs move through the landscape in search of food and oviposition hosts and they exhibit a pronounced “edge effect” during these movements, i.e., they tend to congregate their populations in the border rows of vegetation blocks. This observation suggests that they respond to natural corridors in the vegetation that provide pathways, but they likely do not move through the corridors as they prefer plant cover for protection. Thus, the landscape may be described from the stink bug perspective as a series of corridors and barriers (matrix is the ecological term for the vegetation block) which the vegetation represents. Placement of trap crops relative to the cash crop should exploit these stink bug behavioral tendencies. Trap crops attract stink bugs by vision and odor. While these ecological relationships remain ill defined, the following advice is provided to growers in making decisions about trap crop placement. The vegetation species, structure, size and location outside the target cash crop is important in deterring the source of stink bugs that may emigrate to the trap and cash crop. Trap crops should be placed between the suspected sources of stink bugs and the cash crop borders to intercept moving stink bugs. With smaller acreages, it may be best to plant the trap crop around the entire cash crop’s perimeter, but this is likely not necessary if there are large areas of open space around the cash crop. It may only be necessary to place the trap crop on the cash crops perimeter that is closest to the nearest vegetation. These areas will likely be the location from which the stink bug originates and leaves to move toward the cash crop.

References:
Douce, K., and R. McPherson. 1991. Summary of losses from insect damage and costs of controls in Georgia. 1989. GA Agric. Expt. Stn. Spec. Publ. 70: 46 pp.
McPherson, J., and R. McPherson. 2000. Stink bugs of economic importance in America north of Mexico. CRC Press, Boca Raton, FL, 251 pp.
Schaefer, C., and A. Panizzi. 2000. (eds.). Heteroptera of economic importance. CRC Press, Boca Raton, Fl. 828 pp.

A trap cropping system for stink bug management.

We developed a trap cropping system that is neutral with respect to farm scale and farmer philosophy. Therefore, it is usable by conventional growers as well homeowners, organic and other types of small-acreage producers. Small-acreage producers and home owners also have the option of growing the trap crops in large portable containers to reduce establishment costs and increase the efficacy of the tactic by strategic placement of the trap plants adjacent to a sequence of cash crops.
Hemp sesbania did not attract stink bugs of any species well enough to recommend. Okra did attract green stink bugs and consistently was infested with aphids that attracted large numbers of syrphid flies, ladybeetles and other generalist beneficial species. However, we do not recommend okra as part of a stink bug trap crop system because it matures slowly, is difficult to manage due to harvesting needs and often supports phytophagous soil nematodes.
When the trap crops were planted adjacent to the perimeter of a plot of organically-grown Hinson soybeans, the total number of stink bugs remained much higher in the trap crop than in the soybeans (Fig. 3). While the trap crop plots were managed by ratooning to maintain efficacy, the stink bugs were not removed from the trap crops and destroyed as they would be under commercial conditions. Therefore, this conservative test of the trap crop methodology provided very positive results and strong support for further testing and use by producers.
Description of the trap cropping procedure: All species used in the trap crop system are established using standard culture and management practices. Each species offers certain individual food and visual/odor characteristics that are attractive to the four major stink/leaffooted bug species (hereafter stink bugs) previously mentioned. Stink bugs are highly polyphagous feeders and move through the landscape in search of food and oviposition plants whose qualities vary over time and space. Polyphagy is an apparent manifestation of the stringent requirements stink bugs have for food quality (Fig.s 1 and 2). All four of the major stink bugs and likely all species are very finicky with respect to plant growth stage as it relates to the quality of their food. The state of the preferred food relative to plant growth stage, which we established as part of this study, also varies by stink bug life stage, with nymphs and adults different (Fig. 1). Because of this food quality issue, a narrow window exists for each plant to serve as food for stink bugs. This is critically important because it is necessary to provide a continuous source of high quality food in the trap crop to prevent stink bugs in the cash crop which is at some point also very favorable for stink bug feeding. Thus, the reason why trap crops require multiple plant species is to maintain a continuously competitive food source to out compete the cash crop for stink bug feeding.
To minimize the number of plant species used in a trap crop, it is also necessary to identify species that are attractive, acceptable hosts to as many stink bug species as possible. Prior to this study, host plants that were attractive to both the major stink bug species and to the leaffooted bugs were not well known. In addition, it is necessary to have the trap crop plants available in a high quality state prior, during, and after the cash crop is most susceptible to bug feeding and damage. Lastly, plant species, and their cultivars in the case of food or grain crops, have individual growth characteristics such as maturity date, plant height, and seed head structure, as well as specific requirements for and tolerances to soil, moisture and other habitat factors. These not only determine culture and management practices, but they also may affect stink bug behavior either positively or negatively. For example, sorghum and millet do not germinate and grow well under cool soil conditions, whereas cool conditions are ideal for triticale. Buckwheat matures seed in 3-5 weeks, whereas sorghum and millet may require 60-90 days. Stink bugs appear to respond better to (arrest in the plots) taller plant species and prefer relatively open seed heads.
Presented with these requirements of food quality, multiple target pest species and optimum timing and practicality, along with the inherit limitations of insect behavior and the growth, culture and management of each plant species, we tested a number of plant species and make the following recommendations. These recommendations cover the entire season from spring to summer to fall, attract all of the major stink bug pest species, and many if not most of the minor species, and present a workable plan to suppress stink bugs under any farming philosophy and farm size. While beyond the scope of the project, the plants recommended for trap crops from this study are also very useful for augmentation of beneficial insects, e.g., parasites and predators of stink bugs, as well as many generalist feeders, and for augmentation of pollinating bees and wasps. These factors are attributable to the presence of flowers with their nectar and pollen and the occurrence of aphids and other phytophagous insects on the trap crop plants which may produce honeydew or serve as alternate hosts for beneficials.
For early spring cash crops, we recommend that plantings of triticale be made in fall by staggering several planting dates in October to early November (should be customized to location); earlier plantings may be more effective in more northern locations. Several cultivars may be established to provide a range in plant height (we believe that taller varieties better attract the stink bugs) and maturity dates. Crimson clover and hairy vetch may also be planted at the same time within the plots to augment beneficials in spring. Triticale surmounts the limitations of cool spring soil conditions that prohibit growth of sorghum and millet and the staggered plantings will provide a hedge against total loss of the trap crop from unpredictable spring freezes. The range in maturity dates provided through use of multiple cultivars will prolong the efficacy of the trap crop and insure timely competition with the cash crop relative to food quality. Because sunflower and buckwheat can withstand cooler soil temperatures, these two species can be added to the spring trap crop in early spring. Note that neither buckwheat nor sunflower is totally immune to spring frosts. However, buckwheat is highly important due to its rapid seed formation within 3-5 weeks from planting. Because of this, if planted repeatedly, buckwheat may serve as a “relay” crop between the maturation dates of the other species.
For the summer to fall period, sunflower, buckwheat, sorghum and millet are recommended species for the trap crop. Okra may also be added to further attract stink bugs and enhance the augmentation of beneficial insects; however, all of the other plant species recommended along with augmentation of pollinators perform the same functions. For sorghum and millet, we recommend planting several commercially available cultivars with a range in maturity dates. Sorghum and millet also are amenable to ratooning, i.e., mowing, to increase their temporal efficacy.
Sorghum seed heads remain in the optimum growth stage that is most attractive to stink bugs for a period of 2-4 weeks depending on the weather, cultivar and cumulative bug feeding damage. Ratooning of sorghum works best if the plants are mowed (bush hogged) to a height between 0.5-0.75m after the initially-formed, mature seed heads are no longer attractive to stink bugs. The ratooned plants will tiller (develop multiple stalks) and will set new heads in about 3-4 weeks. However, the plants will be shorter in height and out of synchrony with respect to seed formation; unlike the synchronize seed set derived from the initial seed plot establishment. This is an important and unexpected attribute or “emergent property” that is very useful to extend the temporal efficacy of the trap crop. Millet may also be ratooned, but it does not return seed set as well nor grow as tall as sorghum. Sunflower is not amenable to ratooning while buckwheat is. However, buckwheat is so easily planted and quick to form seed heads that ratooning may be the less desirable management choice. Okra is also amenable to ratooning but requires longer time periods to mature.
All of the recommended species may be cultivated in large containers individually or in multiple species groups for portability and moved around to small plantings in a strategic approach by small-acreage producers or homeowners. Container plants can be ratooned as well.
Trap crop spatial and temporal considerations: Stink bugs move through the landscape in search of food and oviposition hosts and they exhibit a pronounced “edge effect” during these movements, i.e., they tend to congregate their populations in the border rows of vegetation blocks. This observation suggests that they respond to natural corridors in the vegetation that provide pathways, but they likely do not move through the corridors as they prefer plant cover for protection. Thus, the landscape may be described from the stink bug perspective as a series of corridors and barriers (matrix is the ecological term for the vegetation block) which the vegetation represents. Placement of trap crops relative to the cash crop should exploit these stink bug behavioral tendencies. Trap crops attract stink bugs by vision and odor. While these ecological relationships remain ill defined, the following advice is provided to growers in making decisions about trap crop placement. The vegetation species, structure, size and location outside the target cash crop is important in deterring the source of stink bugs that may emigrate to the trap and cash crop. Trap crops should be placed between the suspected sources of stink bugs and the cash crop borders to intercept moving stink bugs. With smaller acreages, it may be best to plant the trap crop around the entire cash crop perimeter, but this is likely not necessary if there are large areas of open space around the cash crop. It may only be necessary to place the trap crop on the cash crop’s perimeter that is closest to the nearest vegetation. These areas will likely be the location from which the stink bug originates and leaves to move toward the cash crop.
The plot size of the trap crop necessary to insure efficacy is ill defined. The key attribute is the quality of the food available relative to the food quality of the cash crop. Due to the tendency of stink bugs to respond to vegetation barriers and concentrate on the borders, the “edge effect”, plot size does not have to be very wide. If plots are established using machinery, then the width of one tractor pass is sufficient. We used a plot size of 3 x 10m but only enough plants are needed to provide management flexibility in maintaining continuous optimum food availability. This can be achieved by planting larger plots and ratooning part of the plot at different times if sorghum and millet are used. Long narrow plots should be used in most cases given the discussion of the factors affecting trap crop placement.

Participation Summary

Educational & Outreach Activities

Participation Summary

Education/outreach description:

A one page print out of a larger poster used at meetings is included to be used as a handout from the project. It provides an overview of the project and its results. It is attached in a separate Powerpoint file and available on the website- ufinsect.ifas.ufl.edu.

Mizell, R., T. Northfield, and C. Riddle. 2006. Trap crops for stink bugs. ESA Ann. Mtg. San Diego, CA, Dec. Poster.
Mizell, R. 2006. Trap crops for stink bugs. NFREC Spring Field Day. Quincy, FL.
Mizell, R., T. Northfield, and C. Riddle. 2007. Trap crops for stink bugs. SEFVC, Savannah, GA, Poster.
Trap Cropping for Stink bugs. Suwannee Valley Twilight Field day, NFREC-Quincy, 1 May. 2007.
Mizell, R. 2007. Trap crops for stink bugs. NFREC Spring Field Day. Quincy, FL.
Mizell, R. 2007. Landscape-level geospatial analyses of stink bug population dynamic. Cumb.-Shenandoah Fruit Work. Conf. Winchester, VA. Nov.
Mizell, R. Website- ufinsect.ifas.ufl.edu: Trap cropping recommendations for stink and leaffooted bugs. September 2007.
Mizell, R., T. Northfield, and C. Riddle. 2008. Trap crops for stink bugs. ESA Ann. Mtg. San Diego, CA, Dec. Poster.
Mizell, R. F. and T. C. Riddle. 2008. A practical trap cropping system for stink and leaffooted bugs. Proc. FL. St. Hort. Soc.
Mizell, R. F. 2007-08. Website: The major project results and recommendations are posted on the author’s website: ufinsect.ifas.ufl.edu, and linked to other UF/IFAS and NFREC’s websites.

Project Outcomes

Project outcomes:

The project has received excellent reviews and comments from producers of all types where ever we have discussed or demonstrated our results (see next section). Trap crops have been discussed and reviewed by scientists from around the world but to our knowledge this is the first practical scheme to have excellent potential for success against a wide range of stink and leaffooted bug species as well as work for the entire range of farmer philosophies and farm scales across a large agricultural production region.

Economic Analysis

Such analyses were beyond the scope of the project but the data can be developed easily and we hope to develop such data in a spreadsheet format in the near future.

Farmer Adoption

The underlying reason for the great interest in this project is that stink bugs are a ubiquitous problem of seed crops and that there are no effective insecticides available for alternative growers to use. The farmers that we cooperated with in demonstrating this project had difficult years due to bad climate spring weather and drought and were unable to fully test the recommendations. However, county agents and producers of all types expressed great interest in the project wherever it was discussed or demonstrated, e.g., the NFREC-Quincy field days and the Southeastern Fruit and Vegetable meeting held in Savannah, GA. Additionally, presentations to other fruit and vegetable scientists provided feedback and generated high levels of interest in the methodology.

Recommendations:

Areas needing additional study

The location for placement and size of plots relative to the cash crop, especially for larger acreage blocks, remains to be precisely determined. This limitation in part is dependent upon developing a better understanding of the relationship of stink bug movement to vegetation patterns and alternative food sources at the landscape level. This is an area that is receiving much research attention. Additionally, the crop phenology will change with location by latitude from year to year and the required presence of the preferred trap crop stage timed to the most susceptible cash crop stages must be managed for the trap crops to function properly. Semiochemical attractants for the southern green and green stink bugs and the leaffooted bugs are not available or are too expensive to synthesize or practical use. This will likely change in the future and when attractants become available they can be incorporated into trap crops to make them more effective at drawing stink bugs to them along with the natural enemies. Meanwhile, the Florida stink bug trap and the attractant for Euschistus spp. can also be incorporated into a trap crop to enhance theattraction and suppression of these species.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.