1. Steps to Getting Started on a Biocontrol Program (HortReport, June 2000)

Transcription

1 1. Steps to Getting Started on a Biocontrol Program (HortReport, June 2000) To many greenhouse vegetable growers, the possibility of using biocontrols sounds great. It means that if done correctly he/she can greatly reduce pesticide use that decreases residues on the product, especially near harvest and is a good selling point to your customers. In addition, reduced pesticide applications make the greenhouse environment safer and allow employees to work in the greenhouse without being concerned about reentry intervals. However, making the transition from relying exclusively on traditional pesticides to a biological control program may seem too difficult. Many PA greenhouse growers are successfully making the transition to biocontrol. The change requires more knowledge of the pest and biocontrol species and a few shifts in management style, but the results are worth it! In the next growing season, consider these steps before initiating a biocontrol program. Managing pests with biological controls requires thoughtful, careful planning and the realization that every crop cycle may present a unique situation. Results are not instantaneous so patience is a must. Hopefully the issues discussed here will minimize some of the pitfalls and risks associated with the adoption of a biocontrol program. Getting Started Start small As with any new technology, start small. Learn the system in one greenhouse and expand as you gain confidence and knowledge. No Pesticide Residues Discontinue using insecticides with residual activity at least one to two months prior to introducing biocontrols. Pesticide residues on plants and greenhouse coverings can be deadly to biocontrol agents. Consult biocontrol suppliers for information on specific products if you want to be certain about the compatibility of a compound that has been applied. before outbreaks occur. Some biocontrol suppliers sell these products, and can give you compatibility information. If you are unsure about the compound you want to apply, consult your biocontrol supplier before spraying. Some growers find it beneficial to have a sprayer designated for soft pesticides only, avoiding contamination with more toxic insecticides. Sanitation Weed management is critical to the success of a biocontrol program both before and during crop production. Weeds serve as reservoirs for pests and diseases and may upset the predatorprey balance you are trying to establish in the crop. It is also critical to maintain a weed free zone around the outside perimeter of the greenhouse for the same reason. Using an herbicide to quickly knock down a well developed weed population will have pests scrambling for another food supply, which will probably be your crop. Remove weeds and destroy on a continuing basis. Clean transplants In many cases, serious pest and disease problems that plague growers throughout the growing season result from purchasing infested transplants. Selection of a reputable grower ensures a quality transplant. Inspect what you are buying! If you are growing your own transplants, follow strict sanitation procedures and inspect seedlings weekly for pest and disease development. Preventing a problem from becoming established can save a lot of time, effort and expense. Start Early Begin introductions of biocontrol agents when pest populations are at low levels so that the biocontrol species is not overwhelmed. This can be determined by weekly crop inspection. For example, even though Encarsia formosa, a tiny parasitic wasp, is an excellent control for whiteflies, the wasp will not be as effective if it is Soft Pesticides Consider the use of soft or reduced risk compounds (i.e. insecticidal soap, ultra-fine horticulture oil, neem compounds) for treating hot spots or pests that are not being controlled biologically. Have products on hand 7

2 2. Greenhouse Sanitation Procedures are Necessary for a Successful IPM Program (HortReport, December 2001) To prepare for next year s spring greenhouse vegetable crop (or any other crop) the end of season cleanup is critical to prevent carry over of pests and diseases to the next crop cycle. Pest exclusion and greenhouse sanitation are cornerstones in establishing a successful integrated pest management program. 1. Remove all plant debris including weeds. Remove weeds outside the greenhouse, especially those near doors and vents. If plants are infested, place them in a bag and destroy. Do not place infested plant material in dump piles near greenhouses. 2. Pressure wash the interior of the greenhouse with a disinfectant solution. 3. Increase greenhouse temperature (when crop has been removed) to over 77 F for several days. This increases the metabolism of pests left in the greenhouse causing them to starve in the absence of a food source. High sunlight and temperature can pasteurize the greenhouse. Heat treatment is preferred over cold treatment since cold temperatures induce insects into hibernation rather than starvation. 4. Eliminate areas of standing water. Insects will perpetuate with a water source. 5. Remove areas of algae since it is a food source and breeding area for fungus gnats and shore flies. 6. Consider the installation of insect screens over vents to prevent entry of whiteflies, thrips and winged aphids. 7. The ground or growth media should be treated for pests and diseases through crop rotation and/or steaming. This will reduce carryover of pests such as thrips and spider mites which hide where they are sheltered until favorable environmental conditions resume. Steaming is effective in eliminating insects, diseases, weeds, and nematodes. in the greenhouse, 1-2 weeks before planting the next crop. If you plan to use pesticides as a corrective measure to destroy pests from a previous crop and are using natural enemies or bumble bees for pollination in the next crop cycle, follow these guidelines. Always use the cleanup procedures listed above when using a chemical treatment. This will reduce the need for chemicals at the beginning of the next crop cycle when the plants are young and tender. 1. Use selective pesticides. These are compounds that are non-toxic or slightly toxic to natural enemies. 2. Use pesticides with short residues. There are compounds that persist for a few days and those that persist for many months. Avoid using pesticides with long residuals especially if you plan to use natural enemies and bumble bees for pollination. 3. Avoid using traditional classes of insecticides such synthetic pyrethroids, carbamates, chlorinated hydrocarbons, and organophosphates. For example, Endosulfan (Thiodan ) requires a three-month waiting period before using bumblebees. 4. Compounds that can be used with short residue periods include pyrethrins (Pyganic, listed on Organic Materials Review Institute), insecticidal soap, horticultural oil and azadirachtin (insect growth regulator). Always consult a biocontrol supplier for specific information on chemicals and their affects on natural enemies. These websites will also provide specific information on many compounds. After crop removal and other greenhouse treatments, place yellow sticky cards in the empty greenhouse to monitor for any lingering winged pests. Check the cards weekly to determine if further action is required. Some growers find it helpful to monitor for pests by placing sticky cards 8

3 3. Production, Distribution and Quality Control of Biological Control Organisms (HortReport, August 2000) Most of the successes in greenhouse biological control have occurred in the Netherlands and the United Kingdom, mainly because these countries together contain more than half of the world s greenhouse acreage. An important event occurred when Koppert (1967), a cucumber grower, entered the natural enemy business. Koppert is currently the international market leader in the field of biological crop protection. Large-scale production of natural enemies such as Encarsia formosa and Aphidius colemani takes place in the main facility located in the Netherlands. In addition to Kopperts, there are several other large producers such as Biobest (Belgium) a leader in bumblebee pollination and biocontrol producer, Novartis BCM (England and California) a division of Novartis Crop Protection and Applied Bio-Nomics Ltd. Canada s largest producer of biological controls. There are also some small companies in the US that specialize in the production of predatory mites, lacewings and trichogramma parasitoids. Distributors for these biocontrol producers are found throughout the US and Canada. For example, International Technology Services (ITS), Lafayette, CO, is the U.S. distributor for Biobest Biologicals. Together with the technical support staff at Biobest, they have a full-time entomologist to answer pest control and pollination questions. A list of distributors in the US can be found at the web site of the Association of Natural Bio-control Producers at: Most distributors require orders to be placed by Thursday (since they must be shipped from Europe or Canada) for delivery the following Wednesday. Products are delivered directly to your farm or greenhouse via UPS, Airborne or FedEx. Insist on guaranteed live delivery and overnight express only. These large natural enemy producers screen for quality and use expiration dates. Check biocontrol shipments for this date and be cautious of suppliers who do not put dates on the material. A nonreputable supplier could have material that is weeks old and not viable. When biocontrols arrive at your operation check for viability. Predatory mites can be monitored by shaking material onto a white sheet of paper and observing movement. Parasitoids such as Aphidius colemani are shipped in bottles. Within 24 hours after placement in the greenhouse check bottles for parasitoid emergence. If you observe high mortality of parasitoids call your distributor immediately. During warm weather months, biocontrols should be shipped with cooling material. Inform employees that you will be receiving biocontrols so that they can be stored in a cool area if you cannot distribute them immediately. Web sites to explore:

4 4. Crop Scouting (HortReport, September 2002) Crop scouting is an important cornerstone of a successful Integrated Pest Management (IPM) program. Early detection and treatment of pests is critical in high value greenhouse vegetable and ornamental crops. When conducted on a regular basis (weekly), insects, diseases and cultural problems are detected early before they become major problems. Instead of relying on a weekly spray program, use this time to scout the crop to determine if a spray treatment is really necessary. Growers who scout weekly feel they save money by avoiding unnecessary sprays in addition to making the environment more worker friendly. A successful scouting program includes weekly visual inspection of plant material and sticky cards. Rectangular 3x5 inch sticky traps are typically used in greenhouse crops. Sticky tapes and ribbons can be used, however these are primarily used for control of insects. Bright yellow is the color most commonly used to trap most species of insects. Keep traps in good condition and change them at least every other week, or weekly, if needed. This will vary with insect population levels. Blue traps are most attractive to western flower thrips and other thrips species. This color is useful in crops that are sensitive to thrips damage and require close monitoring. Figure 1. Blue sticky card often used for thrips scouting. Designate one employee (2 people for larger operations) who will be trained to monitor for pests and evaluate the effectiveness of pest control treatments. Many growers find that hiring a crop/ipm consultant is worth the cost since this person is experienced in identifying problems. Scouting and a biocontrol program When using natural enemies for pest control, a weekly scouting program must be implemented to determine if further introductions (or any other controls) are needed. Scouting for greenhouse pests Aphids Start plant inspection on lower leaves and continue up the plant to the growing tips. As aphids feed on growing tips, the leaves curl, sometimes looking like virus symptoms. Yellow sticky cards are useful in detecting winged aphids. Unfortunately, winged adults on sticky cards may indicate that there are clumped populations already established in the crop forcing them to migrate to less populated areas. Fungus gnats Adult fungus gnats are usually found on the soil surface depositing eggs. Adults can also be detected on yellow sticky cards. Larval stages are found in the top inch of soil but can be hard to see without a hand lens. Raw potato disks (1 to 2 inches in diameter) can be placed on the soil surface to monitor for fungus gnat larvae. If larvae are present, they can usually be seen on the disk within 24 hours. Whiteflies Examine the tops and bottoms of leaves. Larval and pupal stages are found on older leaves while the adults are attracted to younger leaves for egg laying. Thrips Adult thrips will most likely be found in blossoms and larvae on leaves or hidden deep in buds. If you have difficulty detecting thrips, tap the leaves and blossoms over a sheet of white paper. This technique dislodges pests and provides for easier identification. Spider mites In greenhouses or high tunnels, mites usually develop on the undersides of leaves and are often found at certain spots in the greenhouse (near vents, doors, heaters). These areas have a more favorable climate for development (dry, warm). It is important that one recognize the early signs of mite feeding, which is the stippling or speckled effect when chlorophyll is destroyed, that appears initially on the foliage when foliage is still green. In addition, 10

5 it is essential that one use a good hand lens to view populations of mites (or any other pest) in egg, nymph, and adult stages. Scouting tools Hand lens at least 10x or greater Scouting forms and clipboard Flagging tape to mark hot spots for introduction of biocontrols or spot spray Sticky cards, both yellow and blue Consider these points for developing a scouting program Maintain a notebook with scouting records, record weekly data from sticky cards and plant inspection. Allow at least 3 hours of scouting time per acre. This time may vary with the type of crops grown and experience level of the scout. Monitor least infested areas first, heavily infested areas last. Inspect plants using a zigzag pattern between benches. Stop at a minimum of 10 spots within a 1,000 square foot area. Inspect incoming plants immediately to prevent unwanted pest entry. Use sticky cards as a guide, and do not depend on them to determine if the controls are working. Sticky cards should always be combined with crop inspection. Use flagging tape to designate hot spots for biocontrol placement or pesticide treatments. Figure 2. Recording scouting data. Figure 3. Tapping for thrips. 11

6 5. Monitoring Insects on Sticky Traps (HortReport, April 2002) Sticky traps are an important tool in an IPM Program and alert growers to pests that are present. Adult stages of pests such as whiteflies, western flower thrips, fungus gnats, shore flies and winged aphids may be detected on sticky cards. Adult trapping alone may not always be a good indicator of damage being caused by immature life stages; therefore, weekly plant inspection should be used in combination with sticky card monitoring. The information obtained from sticky card monitoring can be used to determine if a treatment is needed, the proper timing of a treatment (biological or chemical), and helps in evaluating the effectiveness of the control actions. Types of Traps Rectangular 3 x 5 inch traps are typically used in greenhouse crops. Sticky tapes and ribbons can be used, however these are primarily used for control of insects. Bright yellow is the color most commonly used to trap most species of insects. Keep traps in good condition and change them at least every other week, or weekly if needed. This will vary with insect population levels. Blue traps are most attractive to western flower thrips and other thrips species. This color is useful in crops that are sensitive to thrips damage and require close monitoring. Interpreting Trap Information To identify insects on sticky traps a 10x to 15x power hand lens will be necessary. Traps should be checked once a week or every 2-3 days if you suspect a problem. Examining traps weekly will give you an idea of population trends. Record the number and type of pests caught on each card. Keep this information for future use. A guide to identifying insects on sticky traps can be obtained through IPM Laboratories, Locke, NY, (315) , ipmlabs@ipmlabs.com or explore this web site for more information: selectnewpest.floriculture.html Fungus gnats and shore flies Fungus gnat adults have long legs and antennae. There is a Y shaped vein on the tip of their wing. Horizontal placement of cards just above the soil surface is more effective than vertical placement. Shore flies have five clear spots on their wings with shorter antennae than a fungus gnat. Hang cards vertically for shore fly monitoring. Thrips Usually the tiniest insect found on traps. The slender abdomen appears pointed at the rear and hairs line the edges of the wings. Female thrips are dark brown compared to the yellowbrown males. Thrips are attracted to both blue and yellow traps. Whiteflies Slightly larger than thrips. White wings become less visible the longer they are entrapped. Monitor at vents and doors for migrating whiteflies. In the fall, the bandedwinged whitefly appears on the cards as the outside plant hosts die. This species appears gray from the black bands across their wings. Winged Aphids Yellow sticky cards will detect winged aphids but not the nymphal stages. Winged aphids may indicate a serious aphid infestation in the crop. Aphids have two distinct black spots on their wings and two tailpipes or cornicles at the rear of their abdomen. Suggestions for using sticky cards Use at least 1 card per 1,000 square feet. Additional cards may be placed near doors, vents and in areas of insect-susceptible plant species. Reduce the number of cards if you are using beneficial insects such as parasites or other winged species. Replace cards weekly if insect populations are high or if there is debris on cards. Place cards in houses before introducing crops to monitor for overwintering pests. A card placed just above the floor level can detect thrips or fungus gnats. Place cards 1-2 inches above plant canopy and move the cards as the plant grows. Place cards near plants that are favored hosts for certain pests. (i.e. thrips on African violets, impatiens, and chrysanthemums) Reduce or eliminate blue traps if you are using bumble bees for pollination. Bumble bees are attracted to blue. 12

7 Adult shore flies have five clear spots on their wings with short antennae. Monitor for thrips in susceptible crops with blue sticky cards. 13

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10 7. Insect Growth Regulators (HortReport, February 2003) Insect Growth Regulators (IGR) are a class of chemicals considered to be biorational or a compound that is less harmful to man and beneficial insects. For most IGRs there are minimal re-entry restrictions. IGRs interrupt or inhibit the life cycle of a pest in one of several ways: They can mimic juvenile hormones, so that insects never enter the reproductive stage of development (become and adult) They interfere with the production of chitin, which makes up the shell of insects They can interfere with the molting process. Timing and application of these compounds is critical since they only affect immature life stages of insects. IGRs typically take several days to have an affect on pest populations so don't expect quick results. In some cases, an insecticide must be used in conjunction with an IGR to provide adult knockdown. It is very important to inspect your crop for the insect stages that are present before using and IGR. Because IGRs do not affect mature insects and have no toxic residues, adult beneficials released into the greenhouse after an IGR application are not likely to be affected. For example, poinsettia growers may use an insect growth regulator in conjunction with a parasite to control whiteflies. This integrated control technique offers growers a safety net when using biological controls and reduces the risk of developing unmanageable whitefly populations. For information on chemical compatibility contact your biocontrol supplier or visit the Koppert BV Website with Side Effects Database: Always consult your biocontrol supplier before using a pesticide when using biological controls. Most of the IGRs are synthetic compounds, however there is one IGR that is derived from the tropical neem tree, Azadirachta indica. Azadirachtin is an isolate from the seeds of the neem tree. For many years, the neem seed and its constituents have been studied for their possible role in pest control. Azadirachtin is a potent disrupter of insect growth in many insect orders. Several products containing Azadirachtin are now commercially available to producers and may contain varying amounts of the active ingredient. Two products currently available to growers are Neemix 4.5 and Azatin XL. These products control many different pests on both vegetable and ornamental crops. Always read and follow pesticide labels to determine if the intended use has been approved. 16

11 8. Plant Elicitors A New Tool for IPM (HortReport, December 2002) A new class of biopesticides called plant elicitors offers growers a new tool for an IPM program. A group of Penn State investigators recently received grant monies through the Pennsylvania Department of Agriculture, Agriculture Research Program to study the use of plant elicitors in greenhouse tomato production. Plant elicitors are unique compounds that send a message to the plant to mobilize its defense mechanisms against pests. These biopesticides offer a distinct advantage over traditional pesticides because they are naturally occurring, are active at very low doses and have no direct toxicity to pests, natural enemies or other non-target organisms. Penn State investigators will be focusing their research on four compounds the EPA registered elicitors harpin (Messenger ), methyl salicylate, methyl jasmonate and ethylene will be tested. Each is a natural product that activates the plant s own defenses against pests. These elicitors will be tested individually and in combination with natural enemies such as predators and parasitoids for control of major greenhouse tomato pests, emphasizing control of whiteflies, spider mites, and powdery mildew. Investigators anticipate that the management recommendations that result from this work for control of pests of greenhouse and high tunnel tomatoes will be adaptable to other greenhouse ornamental and vegetable crops and perhaps even field crops, especially plants that are known to be inducible using elicitors including peppers, eggplant (flea beetles), and potatoes. The plant elicitor, Messenger, is a commercially available product from Eden Bioscience Corporation ( Messenger contains one of a group of proteins called harpins. Harpins are produced in nature by bacterial plant pathogens and when applied sends a message to the plant to mobilize its defense mechanisms. This product will stimulate the plants pest suppression system as well as enhancing plant growth. Messenger may be used for crops in greenhouse, shadehouse, nursery and field production (consult label for list of crops). Nearly 500 field trials have been conducted worldwide on more than 40 crops, including high value crops such as tomatoes, peppers, cucumbers and strawberries; traditional agronomic crops such as wheat, rice, citrus, cotton and tobacco; and ornamental crops such as roses. In addition to disease control comparable or superior to conventional fungicides, Messenger increases seed germination, promotes earlier flowering and fruit maturation, and has been shown to increase fruit quality and yields (Diana Horne, EPA). 17

12 9. Entomopathogenic Nematodes as Part of an Integrated Pest Management Program (HortReport, May 2003) Nematodes are simple roundworms lacking segments or appendages and may be parasitic, free-living or predaceous. An entomopathogenic (insect-parasitic) nematode has a symbiotic association with bacteria that is lethal to many soil dwelling insects, but is very safe for animals and plants. The two genera of insectparasitic nematodes used for pest control include Steinernema and Heterorhabditis. Insect parasitic nematodes have been used successfully to control soil dwelling pests in many industries such as greenhouse, nursery, strawberry, mushroom and turf industries, replacing drenches with synthetic pesticides. Because of the high degree of safety, nematode applications are exempt from re-entry intervals, worker protection standards and do not require a mask or other safety equipment. Nematodes can be applied like most conventional pesticides using a pull behind sprayer, fertigation system, or backpack sprayer. Entomopathogenic Nematode Life Cycle Nematodes are shipped to the grower in the infective juvenile stage. When applied to the soil, the infective juveniles surround the pest insect and enter it through natural body openings such as the mouth, anus, or spiracles, penetrating through to the body cavity. Once inside the body, symbiotic bacteria are released from the nematode gut which multiplies rapidly and causes insect death within hours. The nematodes feed on broken down tissue in the insect cadaver and develop into adults. A new generation of nematodes is produced within two weeks with thousands of new infective juveniles emerging from the insect cadaver in search of fresh hosts. Insects killed by steinernematid nematodes appear brownishyellow, and insects killed heterorhabditids become red and the tissue has a gummy consistency. A partial list of key species of insect-parasitic nematodes Nematodes are host specific; therefore it is important to purchase the correct nematode for your pest situation. The nematodes mentioned below are commercially available. Steinernema carpocapsae the most studied, available and versatile of all entomopathogenic nematodes. They are easily mass-produced and are formulated into a partially desiccated state that provides a long shelf life. Especially effective against lepidopterous larvae, including webworms, cutworms, armyworms, and woodborers, this species is an ambusher, standing on its tail in an upright position near the soil and attaches to passing hosts. Trade name: Exhibit SCO Target Pests: Cutworms, armyworms, billbugs, root weevils, vine weevils, stem borers, fleas, fungus gnats, webworms Crop/habitat: Vegetables, small fruits, turf, ornamentals, greenhouse Steinernema feltiae used to control dipterous (flies) insects, including fungus gnats, and mushroom flies. Offers greater effectiveness at lower soil temperatures. Trade names include: Scanmask, Exhibit SF, Entonem Heterorhabditis bacteriophora the most important entomopathogenic nematodes. It attacks lepidopterous and coleopterous insect larvae among other hosts. The nematode is used most in controlling root weevils, especially black vine weevil in containerized soil. Target Pests: Black Vine weevil, sciarids, grubs (Japanese Beetles) Crop/habitat: Home/garden, lawns, strawberries, ornamentals, tree nurseries, greenhouses For more information, consult these websites: www2.oardc.ohio-state.edu/nematodes Partial list of nematode suppliers Griffin Greenhouse and Nursery Supply (800) IPM Labs, Locke, NY (315)

13 International Technology, Bio Best Products, CO (800) Koppert Biological Systems (800) Syngenta Bioline - Oxnard, CA (805) For another comprehensive listing of biocontrol suppliers and information visit this website: This is the site of The Association of Natural Biocontrol Producers (ANBP), a professional association representing the biological pest management industry. ANBP membership includes producers, distributors, and in addition, users of natural enemies and researchers. Advantages of using entomopathogenic nematodes Compatible with many insect growth regulators and other insecticides. Consult your supplier for specific information or check these compatibility charts. Resistance management tool. No worker reentry intervals Disadvantages of using entomopathogenic nematodes Inactivated by desiccation or ultra-violet light; apply nematodes during early morning or late evening when sunlight is minimal. Require special storage and handling, store nematodes in a cool, dry place out of direct sunlight; refrigeration is sometimes required. 19

14 10. Use Pesticides Wisely With Natural Enemies (HortReport, October 2002) One of the most important considerations before starting a pest control program using natural enemies (biocontrol) is knowing what pesticides have been used on the crop itself and in the greenhouse where you will be using biocontrols. Avoid using conventional classes of insecticides such as carbamates, chlorinated hydrocarbons, organophosphates, and synthetic pyrethroids since they can persist for many months on plants and on the greenhouse structure itself. Insecticides from these classes usually have a negative impact on beneficial insects and on the bumble bees used for pollination. The next most important consideration is determining what pesticides you can use along with the introduction of natural enemies. If a pest outbreak requires a spray treatment, use selective pesticides and spot spray when possible. A selective pesticide has these qualities: Non-toxic or slightly toxic to natural enemies (soft chemistry) Short persistence Does not inhibit development or reproduction of the natural enemies Some compounds may be harmful to beneficials at the moment they are applied, but may have a short persistence (i.e., pyrethrins). After the recommended time period has elapsed, beneficial insects can be introduced again. Always consult your biocontrol supplier before applying any pesticide. On line information on the side effects of pesticides on beneficial insects can be obtained through this website: A list of materials for approved for organic production can be found at the Organic Materials Review Institute website: Pesticide Use Compatibility with Biological Controls (Prepared by Cliff Sadof, Purdue University and Michael Raupp, University of Maryland) Pyrethrins (PyGanic ) Somewhat compatible, short residue, but very broad spectrum. Can be used to clean up a pest population one to two weeks (check with biocontrol supplier) before biocontrols are introduced. Azadirachtin (Azatin XL ) Compatible, insect growth regulator derived from seeds of the neem tree, controls larval stages of insect pests. Microbial insecticides (pathogen biological control agents) Bacillus thuringiensis var. kurstaki Highly compatible, targets caterpillars. Larval stages must feed on plants parts containing the bacteria. Bacillus thuringiensis var. israelensis (Gnatrol ) Highly compatible, targets fungus gnat larvae. Beauvaria bassiana (fungus) (Botanigard, Naturalis T & O ) Compatible, kills some softbodied predators, short residue, broad spectrum. Steinernema feltiae (Nematode) Compatible, targets fungus gnat larvae, low toxicity to humans. Others Horticultural Oil Compatible, inactive when dry, kills soft-bodied insects; pupal stage parasitoids not killed. Insecticidal Soap Compatible, inactive when dry, kills soft- bodied insects, pupal stage parasitoids not killed Consider these points when using pesticides with a biocontrol program If you plan to use biocontrols, transplants should not be treated with long residue pesticides. Check with the plant propagator if you do not start your own transplants. Designate a sprayer for soft pesticides, to be used only in biocontrol houses. Pesticide vapors from a non-biocontrol area may have negative impact on biocontrols. Botanicals 20

15 11. Sources for Biological Controls and Bumble Bees (HortReport, April 2003) There are beneficial insects for all of the major greenhouse pests including, aphids, caterpillars, fungus gnats, mealybugs, scales, shore flies, spider mites, thrips and whiteflies. Using bumble bees for pollination is an effective alternative and can completely replace manual pollination. In addition to saving on labor, bumble bee pollination has many advantages. These advantages include: Bumble bees are active at low temperatures (41 F), windy and cloudy conditions Effective in greenhouses, high tunnels and in open air Bumble bee pollination results in higher yields and large, high quality fruit in crops such as tomatoes, peppers and strawberries. Bumble bee hives are shipped to growers in completely maintenance-free hives. The housing is made of solid, recyclable cardboard with a moisture resistant coating. This a partial list of sources for distributors of biological pest controls and bumble bees. Crop King, (330) FAX (330) Green Spot, (603) , FAX (603) Hydrogardens, (888) , FAX (800) International Technology Services, (800) , FAX (303) IPM Laboratories, Inc., (315) , FAX (315) Koppert Biological Systems, (800) An electronic data base of suppliers of beneficial organisms with information on IPM may be accessed through the California Department of Pesticide Regulation homepage at Or request a written copy: California Department of Pesticide Regulation Environmental Monitoring and Pest Management Branch 1020 N. Street, Room 161 Sacramento, CA (916) For another comprehensive listing of biocontrol suppliers and information visit this website: This is the site of The Association of Natural Biocontrol Producers (ANBP), a professional association representing the biological pest management industry. ANBP membership includes producers, distributors, and in addition, users of natural enemies and researchers. Keep these points in mind when ordering and using biological controls and bumble bees. Most biocontrol distributors require that your order be placed by Wednesday or Thursday for shipment the following week. Beneficials and bumble bees are usually shipped overnight delivery to ensure healthy products. Check with your distributor for shipping charges to your area. The company you are working with should guarantee live, healthy products. Notify them immediately if you feel the quality is poor and you need replacement. Consider these steps before initiating a biocontrol program. Managing pests with biological controls requires thought, careful planning and the realization that every crop cycle may prevent a unique situation. Start Small As with any new technology, start small. Learn the system in one greenhouse and expand as you gain confidence and knowledge. 21

16 Pesticide Residues Discontinue using insecticides with residual activity at least one to two months prior to introducing beneficial insects and bumble bees. Pesticide residues on plants, and greenhouse coverings can be deadly to biocontrol agents. Consult suppliers for information on specific products if you want to be certain about the compatibility of a compound that has been applied. These websites will provide specific information on the side effects of many compounds. Good Sanitation Weed management is critical to the success of a biocontrol program both before and during crop production. Weeds serve as reservoirs for pests and diseases and may upset the predator-prey balance you are trying to establish in the crop. It is also critical to maintain a weed free zone around the outside perimeter of the greenhouse for the same reason. Using a herbicide will have pests scrambling for another food supply, which will probably be your crop remove weeds and destroy! Clean Transplants In many cases, serious pest and disease problems that plague growers throughout the growing season result from the purchase of infested transplants. Selection of a reputable transplant grower ensures a quality transplant. Inspect what you are buying! If you are growing your own transplants, the area used for transplant production should follow strict sanitation procedures. Pest Identification Accurately identify the pest you are trying to control with a natural enemy. Inform the biocontrol supplier of the pest species in your crop so they can recommend the most effective product for the pest and crop situation. Start Early Begin introductions of biocontrol agents when pest populations are at low levels. This can be determined by weekly crop inspection. For example, high populations of pests such as whiteflies reduce the effectiveness of the natural enemy Encarsia formosa through honeydew secretions. The sticky honeydew will interfere with the parasitoid s walking and searching speed and may even cause them to become trapped and die. Scouting Program A weekly scouting program is essential for a successful IPM program. Early detection and treatment of pests is critical in high value greenhouse vegetable crops. Designate one employee (2 people for larger operations) who will be trained to monitor for pests and evaluate the effectiveness of the biocontrols. Only through crop monitoring can you determine if further introductions of biocontrols (or any other controls) are required. Use flagging tape to designate hot spots for biocontrol placement. Monitor at least 1% of the plant population in addition to plants at vents and doors. Record data weekly from sticky cards and plant inspection. Keep this data for future reference. Use sticky cards as a guide, and do not depend on them to determine if the biocontrols are working. Counts may be misleading, especially in the warmer months when there is migration of pests, especially whiteflies, from outside. Yellow and blue sticky cards can be purchased through a greenhouse supply company and from many of the biocontrol distributors. 22