Developing beneficial insect habitat for greenhouses

Final Report for ONE05-037

Project Type: Partnership
Funds awarded in 2005: $9,968.00
Projected End Date: 12/31/2006
Matching Non-Federal Funds: $13,595.00
Region: Northeast
State: New York
Project Leader:
Carol Glenister
IPM Laboratories, Inc.
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Project Information

Summary:

A strong and diverse beneficial insect population is necessary to exert pressure on greenhouse pests but greenhouse plants usually do not offer sufficient habitat to sustain such populations. As a result beneficials move on and growers are forced to resort to chemical interventions to protect plants from pest damage.

This project sought to demonstrate that a habitat of continuously blooming plants would attract and support reproduction of both wild and commercially introduced natural enemies of greenhouse pests. Three sites participated in this trial: 1) a 30-acre, 10-greenhouse operation in central New York called Bakers Acres, 2) a research greenhouse at the University of Vermont and 3) a research greenhouse at Cornell University.

Sites 1 and 3 grouped habitat plants in hanging baskets called “Habitat Plant Systems,” (HPS). These pots contained marigolds (for pollen and Orius harborage), alyssum (for cool season pollen and nectar), lantana (for hot season pollen and nectar) and a barley-cereal aphid banker plant (an aphid natural enemy support). Trial site 2 used bean marigold plants placed on the bench. Commercially raised Orius were released into the Orius treatments at each site and Aphidius colemani was released at sites 1 and 3. We observed and recorded commercial and wild natural enemies and pest presence throughout the season.

Reproducing populations of Orius established at sites 1 and 3. At site 1, the number of Orius per pot was directly correlated with the number of flowers sampled per pot. Site 2 demonstrated a 50% reduction in thrips numbers when Orius were present. At the commercial, unscreened site the HPS attracted 75 times as many wild predators as the culinary herbs. At sites 1 and 3 the aphid banker plants maintained aphid parasites season-long. These aphid banker plants controlled the aphids.

Introduction:

Abstract
  • A strong and diverse beneficial insect population is necessary to exert pressure on greenhouse pests but greenhouse plants usually do not offer sufficient habitat to sustain such populations. As a result beneficials move on and growers are forced to resort to chemical interventions to protect plants from pest damage.

    This project sought to demonstrate that a habitat of continuously blooming plants would attract and support reproduction of both wild and commercially introduced natural enemies of greenhouse pests. Three sites participated in this trial: 1) a 30-acre, 10-greenhouse operation in central New York called Bakers Acres, 2) a research greenhouse at the University of Vermont and 3) a research greenhouse at Cornell University.

    We selected plants that, together, offered beneficials harborage and season-long sources of pollen and nectar, and grouped them in hanging baskets called “Habitat Plant Systems.” These pots, which contained marigolds (for pollen and Orius harborage), alyssum (for cool season pollen and nectar), lantana (for hot season pollen and nectar) and a barley-cereal aphid banker plant (an aphid natural enemy support), were distributed throughout trial sites 1 and 2. Commercially raised Orius and Aphidius were released in April into the greenhouses. We scouted from April to August, observing and recording the presence of natural enemies (both commercially introduced and wild), and pests in and around the Habitat Plants Systems to determine whether offering habitat was an effective way to attract and sustain populations of beneficial insects. At trial site 3 (Cornell), beans and thrips were subjected to 4 treatments in 4 separate greenhouses as follows: 1) crop + thrips, 2) crop + thrips + marigolds, 3) crop + thrips + Orius, and 4) crop + thrips + Orius + marigolds. These 4 treatments were replicated 2 times.

    Noteworthy results include:

    The aphid banker plants at the unscreened site attracted 75 times as many wild aphid predators in 4 families as the culinary herbs and at two sites maintained the establishment of the aphid parasite Aphidius colemani season-long.

    There was a 50% reduction of thrips in the short-term presence of Orius at one of the 3 sites, although this did not exert adequate pressure to control the thrips.
    Detailed observations of the occurrence of Orius on habitat pots on a single day in August found that the number of Orius per pot increased with the number of marigold and lantana flowers in the pot.

    The thrips predator, Orius established season-long in flowering plants at 2 of the 3 sites. However, at two sites, control of thrips was not adequately demonstrated in the presence of the Habitat Pot Systems, presumably because the ratios of predators to prey were too low.

Project Objectives:
  • The objectives of the project were as follows:

    Create “Habitat Plant Systems.” Select plants that offer blooms and pollen such as marigold, sweet alyssum, lantana, and fennel. Include a banker plant, such as barley infested with commercially grown cereal aphids to provide an additional source of food for aphid natural enemies.

    Demonstrate effectiveness of Habitat Plant Systems in attracting and retaining natural enemies in greenhouses for the biological control of thrips, whiteflies and aphids:

    Determine whether Habitat Plant Systems provide a favorable habitat (i.e., enough pollen, nectar and alternate hosts) to support the establishment of introduced beneficial insects such as Orius and Aphidius.

    Determine whether Habitat Plant Systems provide a favorable habitat (i.e., enough pollen, nectar and alternate hosts) to attract and support a diverse wild natural enemy insect complex (such as lacewing, aphid midges, aphid parasites, hover flies and lady beetles).

    Compare pest and natural enemy levels in treated and untreated greenhouses.

    Highlight the sustainable actions of the grower.

    Promote habitat plant systems through literature and education.

Cooperators

Click linked name(s) to expand
  • Jan Nyrop
  • Margaret Skinner

Research

Materials and methods:

Materials and Methods — IPM LABORATORIES/BAKERS ACRES (Trial Site 1)

We selected two greenhouses growing herbs at Bakers Acres of North Lansing, NY. We designated the retail herb house as the house that would have the habitat system installed and the herb stock plant house for a control. The Habitat Plant Systems were added to a retail heated greenhouse that held more than 250 varieties of herbs in small groups and as many hanging baskets of petunias and other flowers as it could hold. The retail house was approximately 94’ by 28’, or 2632 square feet with 24 benches, each approximately 55 square feet. This house is referred to as the HPS treatment. The Control House was a smaller Quonset style greenhouse with large individual herb stock plants used as the parent plants for the herb cuttings. The plants were elevated on pallets on the greenhouse floor.

The Habitat Plant System consisted of 12” hanging baskets that contained 3 Bonanza marigolds, 3 alyssum, 1 lantana, 1 fennel, and a few barley plants with the bird cherry oat aphid, Rhopalosiphon padi (Figure 1, Appendix, hard copy.). Twenty-six Habitat Plant Systems (HPS) were hung in the Habitat Plant System house on March 31, 2005 so that the bases of the baskets were approximately 16 inches above the 24 benches, with the 2 extra hanging baskets placed randomly in case replacement baskets were needed during the summer. Four HPS omitted the barley and aphids, because they were hung near grasses being produced in the house for sale: lemon grass and sweet grass.

Natural Enemy Releases

Natural enemy releases are presented in Table 1, Appendix, hard copy.

Pesticide Treatments

Pest management decisions were made by the production staff. When the thrips numbers were high, the staff sprayed Conserve in the Habitat Plant System greenhouse on June 23. The herb stock plants in Greenhouse 7 were not treated. A small block of sage (about 3 square feet) was treated with horticultural oil and insecticidal soap on May 7 for an intense number of whitefly immatures (some parasitized, but most not parasitized). (Table 2, Appendix, hard copy.)

Natural Enemy Population Monitoring

We monitored the Habitat Plant Systems weekly for signs of the presence and/or establishment of natural enemies. First we walked through the house looking at all 26 HPS quickly and recording the presence of all visible signs of natural enemies both wild and introduced. The rule for the initial survey was “no poking.” We were trying to detect as many natural enemies as possible before causing them to fly or hide. Next, we took our time poking through 10 HPS and looking closely for natural enemies. These 10 HPS were selected at the beginning of the season as permanent sampling sites by dividing the house into 6 sections with 4 benches each and randomly selecting one bench per section on each side of the main aisle by flipping a coin. When the marigolds grew big enough, we also beat the flowers and stems of the marigolds and alyssum on a white paper 3 to 5 times and counted the natural enemies that fell out. The HPS in the western most benches of the greenhouse were not sampled because they did not contain the aphid banker plants.

Pest Population Monitoring

We noted presence or absence (Yes or No) of pests on the HPS every week without doing any counts. We counted and recorded all insects on two 3”x 5” Olson yellow sticky traps per week per house in both the treated and control greenhouses. These traps were placed in pest-prone plants (horehound for whitefly and rosemary for thrips) in both greenhouses, in order to be sure that we detected the pests. We also made weekly inspections of indicator plants from among the herbs to assess pest levels. We selected these herbs based on our prior knowledge of pest harborage. For aphids, we examined ten 4 to 6-inch sections of the curry plant by beating 3 times against a white paper and counting the pests. For whiteflies and spider mites, we examined Horehound and Bee Balm by randomly selecting 4 upper, 4 middle, and 4 lower leaves per plant species and counting and recording the stages of whitefly and the numbers of spider mites. The only spider mites observed were on the Bee Balm. And for thrips, we examined rosemary by individually beating 10 randomly selected six-inch spikes against a white paper and counting the thrips each week.

Orius/Thrips Ratios

At the end of the season, on August 11, we sampled most of the pots to estimate the relative numbers of Orius and thrips in the various flowers by beating the flowers against a white paper. We grabbed 1 to 2 handfuls of marigold flowers and foliage, 1 to 2 handfuls of lantana flowers and foliage, and 1 handful of alyssum flowers and foliage. The number of Orius and thrips found in each sample — as well as the species and number of flowers and stem height of the marigolds and lantana — were recorded. The alyssum flowers were too numerous to count and the stem length too variable to estimate.

Materials and methods for University of Vermont and Cornell University (Trial Sites 2 and 3, respectively) are included in the Results and Discussion section of this report.

Research results and discussion:

IPM LABORATORIES, INC./BAKERS ACRES OF NORTH LANSING (Trial Site 1)

Orius Establishment and Thrips Control

The Habitat Plant Systems served double duty in thrips control by both supporting the reproduction of Orius and attracting thrips into the pots.

Figure 2 (in Appendix, hard copy) shows the weekly counts of the thrips predator adults and immatures, Orius insidiosus, in the Habitat Plant Systems. Any presence of nymphs is evidence of on-site reproduction by Orius. Images 1and 2 (in Appendix, hard copy) show an Orius nymph and an Orius adult which were collected from HPS. We count this kind of establishment of Orius to be a major success, for we must demonstrate residence by Orius before we can hope to demonstrate long-term control. Figure 3 (Appendix, hard copy) depicts the number of Orius found per hour on the HPS in comparison to the numbers found on the herbs sampled throughout the season. Nearly all the Orius detected season-long were found in the Habitat Plant Systems. In a final survey of the Habitat Plant Systems on August 11, 2005, we detected 123 Orius and 321 thrips on 149 flowers (marigold, lantana, and alyssum). The data showed that the average number of Orius detected per habitat pot increased with the number of flowers in the pot (Figure 4, Appendix, hard copy), with the average number of Orius per flower between 0.5 and 1. Since the literature states that Orius kill 5 to 20 thrips per day, an average of 3 thrips per flower in the presence of Orius may not be cause for alarm, especially if the Habitat Plant Systems are more attractive to thrips than the actual greenhouse crop.

Although we were successful at establishing the Orius, we did not count the trial as an unqualified success because the thrips numbers circulating through the greenhouse in late June were quite high and required a treatment of Conserve to reduce the thrips. The Habitat Plant Systems were removed from the greenhouse before treatment and returned after treatment. This method maintained the Orius populations, while removing most of the thrips with no more treatments required that summer. Figure 5 shows the weekly average numbers of thrips found per 6” spike of rosemary throughout the period. This exceeded 4 just prior to the Conserve treatment, and then fell back to below 1 for the rest of the season.

Aphid natural enemies

Aphid parasites and wild aphid natural enemies reproduced so dramatically on the barley banker plants that we never saw large numbers of aphids anywhere on the retail herbs all season. Image 3 shows aphid mummies on a barley leaf from one of the aphid banker plants. Image 4 shows a lantana leaf with both an aphid mummy and a lacewing egg case that is hatched. The curry plants that we selected to observe for aphids at the beginning of the season averaged a maximum of 1 aphid per 3” tip all season (Fig. 6). This is a very low number. Note that the stock plant control (a mature curry plant) had even fewer aphids, but this can be explained by mature plants having less active growth, therefore being less attractive to aphids than the small actively growing cuttings in the retail herbs. The large upsurge in aphid parasite numbers was demonstrated by more than 200 aphid parasites caught per yellow sticky card between May 26 and June 6. (Figure 7, Appendix, hard copy.) Evidence of aphid demise on the herbs could be seen here and there where a few mummies would dot the herbs with no evidence of live aphids in the vicinity. Aphid parasites were observed on patrol for the rest of the season in the trial herb house. In contrast, the parasitic wasp catch on the yellow sticky cards in the control herb greenhouse was almost zero all season.

The grower had reported in November 2004, before the start of the project, that aphids were her biggest problem and whiteflies her second biggest problem in the herb house. Her records showed that in April 2004 and April 2003 she treated with Botanigard for aphids and a few whitefly. Then in July both years, she treated the herbs with Safer’s Soap for aphids. In 2005, the grower still used Botanigard and horticultural oil in early April, just before we installed the beneficials on the Habitat Plant Systems. However, she never felt the need to treat the herb house for aphids or whiteflies in July.

Wild Natural Enemies

The aphid banker plants attracted 4 families of wild aphid predators and maintained aphid parasites season-long. The Habitat Plant Systems attracted significantly more predators than the herbs and very few predators of any kind were detectable on the herbs season- long (Figure 8, Appendix, hard copy). Image 5 shows a lacewing egg on a barley leaf. The adult lacewing probably laid her egg there due to the presence of the banker plant aphids. Image 6 shows a jumping spider from one of the HPS. Jumping spiders were frequently found in the HPS. Image 7 shows a young lady beetle larva from one of the HPS.

Whitefly Natural Enemies

Whitefly natural enemy establishment on the Habitat Plant Systems also occurred because one of the Habitat plants, lantana, is among the most prolific producers of whitefly in the greenhouse. True to form, when it was placed in the Habitat Plant System, it brought its own greenhouse whitefly. Three weekly introductions of the whitefly parasite, Encarsia formosa followed the introduction of these lantana plants into the herb house Habitat Plant Systems. The final Habitat plant survey on August 11 showed no whitefly evidence on the younger leaves of the lantana (Image 8), and frequent parasitized whitefly scales on the older leaves (Image 9). No adult whiteflies were seen on any of the Habitat Plant Systems, although an occasional whitefly could be seen in the greenhouse.

UNIVERSITY OF VERMONT, Entomology Research Laboratory (Trial Site 2) Participants: Margaret Skinner, Michael Brownbridge, Tom Doubleday, and Cheryl Frank.

For this study the University of Vermont chose two research greenhouses: their Best Management Practices greenhouse was the trial site and their Conventional greenhouse was the control. Each greenhouse is 30×50 ft. Their Habitat Plant Systems contained barley, alyssum, English daisy, and lemon gem, hero yellow and antiqua yellow marigolds. UVM used a slightly different strategy from trial site 1, placing Habitat Plant Systems in both the trial and the control greenhouses, and releasing beneficials only in the trial house. Below are some of their observations (see Appendix, hard copy, for entire report):

Beneficials (Orius insidious and Aphidius colemani) were released in the trial greenhouse only. When native (wild) beneficials (Orius, Aphidius, hover flies and others) turned up in the control house they were found on the Habitat Plant Systems.

Total Insect Occurrences: The following beneficial insects were found on the Habitat Plant Systems in UVM’s trial greenhouse: Orius (21 occurrences), Aphidius (172 occurrences) and Encarsia (2 occurrences). Most notable, however, was the appearance of wild hover flies (10 occurrences) on the Habitat Plant Systems despite the house being screened to exclude infiltration by wild insects.

The hover flies were observed hovering around the alyssum.

Thrips presence was higher in the control house than in the trial greenhouse.

Western flower thrips were lower in the trial greenhouse possibly as a result of suppression by beneficial insects within the Habitat Plant Systems.

In the trial greenhouse, barley had the highest overall insect occurrences followed by lemon gem marigolds, alyssum and English daisies.
Lemon gem marigolds may have offered the most pollen of all the Habitat Plant species, which might account for the higher numbers of thrips and Orius observed there.

More insects were found on barley banker plant (part of the Habitat Plant System) primarily due to the inoculation of these plants with the Bird Cherry Aphids that were used to sustain the introduced population of Aphidius within the greenhouse.

There were no insects found on the barley plants in the control house. It appears that barley attracts insects only when it functions as a banker plant (which turns it into an insectary).

Aphidius was the most dominant beneficial presence on the Habitat Plant Systems in the trial greenhouse followed by Orius and wild hover flies.

During the duration of the experiment, routine scouting found Orius on other plants on three occasions where their presence on the bench was in the vicinity of the Habitat Plant Systems overhead.

In the control house, where no beneficials were released, native (wild) Orius and Aphidius were found on the English Daisies and Lemon Gems.
While the Habitat Plant Systems were in the greenhouse the Aphidius population was the highest it had been all year.

Throughout the duration of the experiment, aphid mummies were always present on all the Habitat Plant Systems at a medium to high density.

CORNELL UNIVERSITY, Department of Entomology. (Trial Site 3) Participants: Jan Nyrop, John Sanderson, and Todd Ugine.

Four greenhouses were each filled with eight 10.2 cm pots spaced evenly throughout the 3.7 m2 of available bench space, on two separate occasions (August and December of 2005). A single “Roma” bean was sown in each pot in Pro-Mix BX peat based media. In two of the greenhouses, four additional pots were added, each containing a single marigold plant, Tagetes patula (cultivar Bonanza Bolero), with two flowers; plants were approximately 4 weeks old. Marigolds were placed in the interior corners of the plot of beans (three rows in from each edge). Twelve and sixteen days after the beans were sown, in tests one and two respectively, 80 adult female western flower thrips, Frankliniella occidentalis, were collected from a laboratory colony and were added to the center of each plot of beans. Additionally, two greenhouses, one with and one without marigolds, had twenty commercially produced adult female and four adult male Orius insidiosus added; in test two a second release of Orius at the same application rate was made 10 days after the initial release. Thus, the treatments were 1) beans + thrips, 2) beans + thrips + marigolds, 3) beans + thrips + O. insidiosus and 4) beans +thrips + marigolds + O. insidiosus. O. insidiosus in the house containing marigolds were added directly to the marigold plants; five females and one male/plant. O. insidiosus in the house without marigolds were added to interior corners of the bean plot (three rows in from each edge). Thirty randomly selected bean leaves were collected from each greenhouse weekly and placed into snap-cap vials filled with 70% ethanol. In test two, ten whole bean plants and one marigold plant were removed on the last sample date. Leaf samples and whole plants were returned to the laboratory and the number of immature and adult thrips and O. insidiosus were enumerated.

Inspection of the mean number of thrips in treatments that included marigolds revealed that thrips abundance was 16 % lower and 25 % higher than treatments that did not include marigolds in tests one and two, respectively (Table 3, Appendix, hard copy). Thrips abundance in treatments that included Orius was 50% and 58% lower than treatments that did not include Orius. Orius were recovered in both treatments that included and did not include marigold flowers. At the end of experiment one (week 3), marigold plants to which O. insidiosus were added were tapped onto a single sheet of white paper. Plant tappings recovered four adult and one immature O. insidiosus. In the second test, two adult (each in the thrips + Orius + marigold treatment) and four immature Orius (all in the thrips + Orius treatment) were recovered; one adult in the first and third weeks of sampling and four immature in the third week of sampling, all on bean leaves; additionally one nymph was observed walking on a bean leaf in the second week. Because of the limited amount of data any conclusions should be viewed as preliminary. The lower thrips abundance (54 % lower on average) at the end of each experiment in treatments that included Orius are likely due to the released predators consuming adult female thrips. This would effectively lower the initial thrips population and cause population growth to slow with respect to treatments that did not include Orius.

Recovery of immature Orius was low in all treatments in which Orius were released; a total of four in samples of beans in the absence of marigolds in comparison to the single recovery of a nymph from marigold flowers. The reasons underlying this low rate of recovery are not known. It is possible that marigold pollen may contribute to reproduction of Orius, although reproduction may also have occurred as a function of Orius feeding on thrips, which is supported by finding of immature Orius in the absence of marigolds. Furthermore, the recovery of adult Orius only occurred in houses containing marigolds. The presence of marigold plants in greenhouses seemed to have no effect on thrips populations either in the presence or absence of Orius.

One serious confounding factor in test one was that thrips abundance was not equal among the greenhouses at the start of the experiment. The greenhouse that started with the greatest number of thrips ended with the most thrips. Similarly, the greenhouses that started with the lowest number of thrips ended with the lowest number of thrips. Ideally, as was the case in test two, the starting number of thrips in each greenhouse should be equal to avoid this confounding effect. We assume that because the bean plants were each sown in their respective greenhouses, that thrips colonized the bean plants before we actually inoculated the plants. In test two, all bean plants were sown in the same greenhouse and randomized to their respective treatments the day that thrips and Orius were added. Different rates of thrips colonization from outside the greenhouse in test one are likely the cause for the different numbers of thrips among the treatments. This is supported by the fact that the growth rates among the treatments are almost identical, in all but the thrips + Orius treatment. (Tables 4 and 5, Appendix, hard copy.)

Research conclusions:

Augmentation and Conservation

Augmenting and conserving beneficials are critical components of an effective integrated pest management program. This project showed that pest managers and greenhouse growers can sustainably attract natural pest control agents by practicing habitat management. Supporting the plants that harbor beneficials that control pests enables growers to remain or become “green” by reducing their reliance on reactive pest control measures, such as pesticide use.

Augmentation: In two of three trials the Habitat Plant Systems attracted and supported a diverse population of beneficials, both commercially reared (Orius and Aphidius) and wild (hover flies, lacewing, lady beetles and Aphidoletes). In one trial wild hover flies found the habitat plants almost as soon as the doors to the habitat greenhouse were opened for ventilation and in another trial hover flies were discovered during scouting despite screens designed to keep wild insects out.

Conservation: In one house we were able to demonstrate the successful conservation of natural enemies despite treating the test house with pesticides. We did this by removing the Habitat Plant Systems (and as a result many of the beneficials living on them), before the house was sprayed with an insecticide on June 23 for the control of thrips. The Habitat Plant Systems were returned to the greenhouse the following day. Scouting a week later revealed that most of the beneficials had survived the event despite the fact that a beneficials-toxic pesticide was used. Conservation of beneficials means the grower’s economic investment in pest management is protected. Another impact of this demonstration is that greenhouse growers do not have to abandon all pesticide use in order to successfully use beneficials. Maintaining beneficials habitat is compatible with combination programs that use multiple forms of pest control (true IPM).

Scouting Methodology

Methodology was developed to assess natural enemies in relation to pests. Natural enemy detection is normally a rare event. The natural enemies were detectable on the Habitat Plant Systems and nearly undetectable in the crop itself.

High Resolution Photographs of Beneficial Insects

Just as the Habitat Plant Systems provide a concentrated focal point of insect presence in the greenhouse they also afford an excellent opportunity to photograph normally elusive beneficials. We brought three Habitat Plant Systems (loaded with beneficials) from the Bakers Acres trial greenhouse to biological photographer Joe Ogrodnick’s laboratory at the NYS Agricultural Experiment Station. Joe was able to produce nine high resolution, color digital photos of beneficials in all stages of development. These textbook quality photographs are used in presentations, articles, and other educational outreach efforts. (Images 1-9, Appendix, hard copy.)

Marketing

Each of the plants contained in the Habitat Plant System was marketed at Bakers Acres under the name Blooms for Beneficials™. Blooms for Beneficials™ laminated signs, complete with an artist’s watercolor rendition of either a marigold, lantana, fennel or alyssum in bloom were distributed throughout the operation where individual habitat plants were being sold. This extended the education process beyond the test greenhouse throughout the entire operation and indicated to customers plants that are known to offer habitat to natural enemies. (Images 11-14, Appendix, hard copy.)

We used this project to educate Bakers Acres and its customers on how plants can be used to leverage the power of natural enemies by providing the resources necessary to allow beneficials to remain and reproduce.

As a result of participating in this project, Bakers Acres was able to demonstrate their commitment to sustainable growing principles and practices, and educate their customers as to why sustainability in agriculture matters.

New Product Development

Product One: The barley-cereal aphid banker plant attracted and supported aphid natural enemies so effectively that IPM Laboratories, Inc., has decided to add this system to its 2006 product line. This will be the first time this banker plant system will be produced and marketed in the United States. (It has been produced and marketed in Canada for several years.) IPM Labs has received APHIS permits for interstate movement of this banker plant system in 41 states including the Northeast.

Product Two: In the early season, when the Habitat Plant Systems were more advanced than the general hanging baskets, customers repeatedly asked if they could buy the HPS which were distributed throughout Bakers Acres trial greenhouse. Although habitat plants are not new, selling plants for the express function of providing habitat for beneficials is. If they wish, greenhouses can create extra HPS for sale or point of interest signage can indicate which plants are habitat plants so that customers can create their own habitat-rich gardens.

Collaboration

Before this project we did not have an opportunity to collaborate with the two horticulturalists at Bakers Acres. We discovered that our combined entomological and horticultural knowledge worked synergistically and strongly contributed to the successful creation and maintenance of the Habitat Plant Systems. Reenie Sandsted and Cathy Kessler, of Bakers Acres, selected the lantana to provide pollen and nectar during the hot summer months. They also maintained the Habitat Plant Systems so that most of the plants survived throughout the season. A major breakthrough occurred when Reenie’s automatic response to normally overcrowded barley banker plants was to break one banker plant into 26 very small units and place one unit in each of the habitat plant baskets. Those barley units lasted all summer long while another overcrowded banker plant was dead within 10 weeks.

Participation Summary

Education & Outreach Activities and Participation Summary

Participation Summary

Education/outreach description:

This grant project, preliminary results and data were presented at the following conferences:
Workshop: A class and hands-on workshop was offered at Bakers Acres during March 2005. 15 people attended. Included in the class was a tour of the herb house complete with hanging Habitat Plant Systems, a presentation on how the use of habitat can influence the diversity of natural enemies in the garden and greenhouse, and an opportunity for attendees to prepare their own habitat systems to take home with them.

Association of Educational Research Greenhouse Curators (AERGC) Annual Meeting, “Managing Historical Collections: The Plants and The Pests.” New York City. July 25-28, 2005. Approximately 100 members attended our presentation titled “Adventures in Creating Greenhouse Habitat for Beneficials.

Camp Casowasco, Moravia, NY. August 10, 2005. Spoke for one hour on habitat plant systems to girls in their early teens. Camp counselor: Ron Murdoch. Approximately 11 attendees.

Association of Zoological Horticulture (AZH) 2005 conference “Growing Sustainability.” Chicago. September 17-21, 2005. Approximately 70 members attended our presentation entitled “Adventures in Creating Greenhouse Habitat for Beneficials.”

2005 New England Vegetable and Fruit Conference. Manchester, NH. December 14, 2005. “Successful Biological Control of Insects and Mites in Tomato Greenhouses.” Approximately 50 people attended our presentation.

Tri-state Greenhouse IPM Program 2006 Hands-On Workshop. “Plug Production A-Z and Novel Strategies for Integrated Pest Management.” January 4-6, 2006. Manchester, ME, Durham, NH and Burlington, VT. This day-long program was presented in each state and was designed to enable greenhouse growers, extension specialists and professional pest managers the opportunity share and discuss best practices and emerging IPM issues. NeSARE grant project leader, entomologist Carol Glenister and trial participant, horticulturalist Cathy Kessler discussed using banker and habitat plants to attract natural enemies in their presentation “Strategies to Enhance Biological Control: Banker and Habitat Systems.” Approximately 135 participants attended the workshops.

Mid-Atlantic Fruit and Vegetable Convention “Beneficials in the Greenhouse.” Hershey, PA. January 31, 2006. Approximately 27 people attended our presentation.

2006 Cornell Greenhouse Update. Boyce Thompson Institute, Ithaca, NY. February 22, 2006. “Adventures in Creating Greenhouse Habitat for Beneficial Insects.” Approximately 73 attended our presentation.

2006 Geneva Greenhouse Update. NYS Agricultural Experiment Station, Geneva, NY. February 24, 2006. “Adventures in Creating Greenhouse Habitat for Beneficial Insects.” Approximately 42 attended our presentation.

International Organization of Biological Control Western Palearctic Regional Section Working Group Annual Meeting entitled: “Landscape Management for Functional Diversity,” Zurich-Reckenholz, Switzerland. May 16-19, 2006. One of two US attendees, Carol Glenister presented a poster entitled “Natural Enemy Observations on Habitat Plants Placed in a Greenhouse Growing Culinary Herbs and Bedding Plants,” during Session 2: Effects of Field and Margin Management – Ecosystem and Spatial Aspects. (See Image 10, Appendix, hard copy.)

Press Releases

Press releases associated with this grant were submitted to the following publications, trade journals, newsletters and newspapers: American Nurseryman, Auburn Citizen, Association of Zoological Horticulture, GMPro, GrowerTalks, Ithaca Journal, Pennsylvania Vegetable Growers Association (PVGA), Pennsylvania Association of Sustainable Agriculture (PASA), Small Farm Today, Syracuse Press and the Tomato Magazine, Sustainable Tompkins Newsletter.

Project Outcomes

Project outcomes:

Profitability

The Habitat Plant System demonstrated a method of sustainable aphid control wherein farmers grow their own beneficials on-site using plants. The need for repeated purchases of aphid parasites is eliminated by ongoing production of aphid parasites by the aphid banker plant, making the cost of the parasites affordable. For the cost of $15 for a single aphid banker plant, Bakers Acres attracted many free wild aphid natural enemies. They were also able to support, season-long, a purchased natural enemy, Aphidius colemani, ($24.25). Without the aphid banker plants, they might have found themselves buying aphid parasites every other week throughout the spring, and then again in the fall in order to protect themselves during aphid season for a total of 6 to 8 purchases ($145.50 to $194).

Farmer Adoption

We acquainted more than 450 greenhouse growers with the concept of habitat support for natural enemies by demonstrating two methods that they can use to implement the strategy. The growers will choose many more plants to support natural enemies as they become familiar with the concept. Bakers Acres opted to trial the Habitat Plant Systems for a second year. Three other growers have expressed interest in promoting the Habitat Plant Systems and several others have requested the HPS point of interest signs and literature.

Assessment of Project Approach and Areas of Further Study:

Areas needing additional study

This project demonstrated that habitat attracts and supports beneficials, enticing them to establish themselves in the greenhouse. Our next goal is to demonstrate that habitat-dwelling beneficials sufficiently control a variety of greenhouse pests, naturally and sustainably.

Additional work will be needed to determine which plant/beneficial combinations work best for specific greenhouse crops, like tomatoes or poinsettias.

It would be valuable to survey growers who are maintaining healthy populations of beneficials to learn which plants they use to support those beneficials.

To advance monitoring methods to include beneficials awareness and to investigate various decision making models that might issue from scouting observations.

To create decision-making guidelines for acceptable ratios of pests to natural enemies.

Information on how far beneficials hunt from plants – i.e., demonstrate impact on pests in crop pants.

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.