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800-346-9140 GREENHOUSE IPM: SUSTAINABLE APHID CONTROL Appropriate Technology Transfer for Rural Areas PEST MANAGEMENT TECHNICAL NOTE www.attra.ncat.org ATTRA is the national sustainable agriculture information center funded by the USDA’s Rural Business -- Cooperative Service.

Abstract: This publication summarizes IPM for greenhouse aphids on both vegetable and ornamental crops. Focus is on monitoring, sanitation, biological controls, biorational pesticides, and insect growth regulators. Supplemental tables include information on the newest biopesticides and biological control organisms.

By Lane Greer NCAT Agriculture Specialist June 2000

The following document focuses on least-toxic methods for dealing with aphids in greenhouses. For general information on greenhouse IPM, request ATTRA’s publication Integrated Pest Management for Greenhouse Crops, which covers topics such as screening to eliminate pests, weed management, and disease control.

Introduction

There are approximately 4,000 aphid species in the world. Life cycles and preferred hosts vary with each type of aphid. Common aphid pests of greenhouse crops include the green peach aphid Courtesy Of Hercules Inc., Wilmington, Delaware (Myzus persicae), the melon/cotton aphid (Aphis gossypii), the chrysanthemum aphid (Macrosiphum rosae), the potato aphid (Macrosiphoniella sanborni), the rose aphid (Macrosiphum euphorbiae) and the foxglove aphid (Aulacorthum solani) (1). Contents The green peach aphid is probably the most Introduction...... 1 notorious aphid pest of greenhouse crops because Crop Scouting and Trapping...... 2 of its wide host range, worldwide distribution, Biological Control...... 2 number of viral diseases it vectors, and difficulty Biorational Pesticides...... 2 of control (2). Insect Growth Regulators ...... 3 Summary and Further Resources ...... 4 Aphid management relies on understanding that References...... 5 the females of many aphid species do not have to Biological Control Suppliers...... 5 mate in order to reproduce, and they typically Appendix 1: Beneficial Organisms...... 8 produce live young, rather than eggs. These Appendix 2: Biorational Pesticides...... 11 characteristics contribute to the tendency of aphid populations to "explode."

IS A PROJECT OF THE NATIONAL CENTER FOR APPROPRIATE TECHNOLOGY Crop Scouting and Trapping Biological Control

Plants should be visually inspected for signs of There are several biological control options for an aphid infestation. Look especially carefully at greenhouse aphid pests. Some common plants prone to aphid problems, and at plant biological control agents (BCAs) include green parts like the undersides of leaves, stems, and lacewings (Chrysoperla carnea, C. rufilabris, new growth. Choose plants randomly Chrysopa spp.), aphid midges (Aphidoletes throughout the greenhouse and inspect aphidimyza), parasitic wasps (Aphidius colemani undersides of leaves, buds or tip growth and and Aphidius matricariae) and lady beetles watch for honeydew and cast skins. Since aphids (Hippodamia convergens). See Appendix I: are difficult to see on plants with fine foliage, Beneficial Organisms for more BCAs and hold such plants over a white piece of paper and suppliers. gently tap to dislodge any aphids. Avoid moving infested plants to new areas where susceptible A 1998 study showed that green lacewing larvae plants are growing. Locations where aphids are did not disperse as well as the parasitic wasp found should be flagged, so that population Aphidius colemani (3). To achieve equal aphid development and control efforts can be suppression, more of the slower-moving species evaluated. need to be introduced and from more points (lacewings have to be released on each bench Different aphid species tend to populate different because they cannot move to adjacent benches, parts of their host plants. Green peach aphids for instance). A study performed at Colorado tend to cluster on the succulent young growth, State University compared the effectiveness of whereas melon aphids are usually evenly parasitic wasps, aphid midges, lady beetle larvae, distributed along the plant stems. Melon aphid and green lacewing larvae (4). The researchers populations also have fewer winged adults than found that lacewings performed better in hot do green peach aphids. Knowing which species temperatures, while aphid midges and lady is infesting the crop is very important in beetles were better in cooler temperatures. At all successful detection and monitoring of aphid temperatures, Aphidoletes was the best of the four populations. The Cooperative Extension Service at controlling aphids. is a good resource for identification of specific aphid pests. Biorational Pesticides Yellow sticky cards placed horizontally at the top of the pot or container (if you are growing Strains of the fungus Beauveria bassiana provide containerized plants) can be used for monitoring good control of aphids, including green peach winged aphids. However, since winged aphids aphids. The fungus works by attaching to the caught during the summer months may have outside of the pest, then penetrating into the blown in from the outdoors, sticky cards are not body and killing it. The fungus is available as reliable as visual inspections. Sticky cards are commercially for greenhouse ornamentals as more useful in the winter months when aphids Naturalis-O™ and for vegetables as caught on the cards are not likely to have come in BotaniGard™. (See below for suppliers.) from the outside. It is better to rely primarily on visual inspections for aphid detection, and use Another fungus, Verticillium lecanii, can also sticky cards as a backup method. provide good biological control of aphids. Formulations of this fungus are currently being Signs of an aphid infestation include honeydew sold in some European countries under the or sooty mold on leaves, yellow spots on upper names of Vertalec™ and Mycotal™, but neither leaf surfaces, cast skins on leaves, curling of of these products is yet registered for use in the leaves, and distortion of new growth. United States.

// GREENHOUSE IPM: SUSTAINABLE APHID CONTROL Page 2 Verticillium lecanii often occurs naturally in target species, such as humans, birds, fish or greenhouses, so it may be possible to encourage other vertebrates. For most IGRs there are its growth and distribution in the greenhouse minimal re-entry restrictions. IGRs typically take without the benefit of a commercially available several days to have an effect on pest product. V. lecanii spores require at least 93% populations. Because IGRs do not affect mature relative humidity at temperatures between 59 insects, adult beneficials released into the and 81°F to germinate and grow (6). High greenhouse after an IGR application are not likely humidity must be present for at least 10–12 to be affected. Use of IGRs is generally hours/day. Unfortunately, most plant disease- prohibited by organic certification organizations causing fungi also grow best at these same because the products are synthesized. temperature and humidity ranges. Fungicides used to control the plant disease-causing fungi IGRs can sometimes be used in conjunction with would probably also kill any beneficial fungi biological control efforts and may provide present. Insecticides may also be harmful to V. growers with a “safety net” should beneficials lecanii. fail to keep the pests below economically damaging levels. The table below lists some Least-toxic pesticides used against aphids in well-known insect growth regulators. (Contact greenhouses include insecticidal soap (M- information for suppliers is listed at the end of Pede™), horticultural oil (UltraFine SunSpray this document.) spray oil™), and botanical insecticides such as neem (Azatin™, Neemazad™, and Neemix™), or natural pyrethrums. See Appendix II: Biorational Pesticides for more information and suppliers.

Insect Growth Regulators

Insect growth regulators (IGRs) are another least- toxic pesticide control option for pests. IGRs typically kill insects by disrupting their development. They have a complex mode of action that precludes insects from rapidly developing resistance. IGRs can work in one of several ways: 1) they can mimic juvenile hormones, so that insects never enter the reproductive stage of development; 2) they can interfere with the production of chitin, which makes up the shell of most insects; or 3) they can interfere with the molting process. IGRs usually work through ingestion, so good spray coverage is essential. They generally don’t affect non- Courtesy of Hercules Inc. Wilmington, Delaware

// GREENHOUSE IPM: SUSTAINABLE APHID CONTROL Page 3 Table 1. Selected Insect Growth Regulators

Brand Name Supplier Active against:

Azatin Hydro-Gardens, Olympic whiteflies, leafminers, thrips, Horticultural Products mealybugs, fungus gnats, aphids, cabbage loopers, diamondback moths, armyworms

Enstar II Wellmark Intl. whiteflies, fungus gnats, aphids, soft and armored scales, mealybugs

Neemazad Thermo Trilogy whiteflies, leafminers, thrips, mealybugs, fungus gnats, aphids, cabbage loopers, diamondback moths, armyworms

Neemix Thermo Trilogy whiteflies, leafminers, thrips, mealybugs, fungus gnats, aphids, loopers, diamondback moths, armyworms, cabbage loopers

Preclude Whitmire Micro-Gen whiteflies, thrips, scales, aphids

Summary and Further Resources

Greenhouse aphids are tiny insects, but they control measures that dovetail very nicely with demand serious attention on the part of the the IPM philosophy. In the resources sections greenhouse grower. Integrated pest management below, growers are provided with a list of offers a sustainable approach for dealing with biological control suppliers; and tables that greenhouse aphids, and safer pest control summarize biocontrol agents and biorational products facilitate the adaptation of least-toxic pesticides that control aphids.

Related ATTRA Materials

• Organic Greenhouse Vegetable Production • Integrated Pest Management of Greenhouse Crops • Greenhouse IPM: Sustainable Thrips Control • Greenhouse IPM: Sustainable Whitefly Control

// GREENHOUSE IPM: SUSTAINABLE APHID CONTROL Page 4 References: Caltec Agri-Marketing Services PO Box 576155 1) Lindquist, Richard. 1991. A guide to aphid Modesto, CA 95357 control. GrowerTalks. October. p. 75. 209-575-1295 209-575-0366 fax 2) Sunderland, Keith et al. 1992. Integrated pest http://www.caltecag.com management of greenhouse crops in Northern Europe: Aphids. p. 23–30. In: Jules Janick Florikan ESA Corp. (ed.) Horticultural Reviews: Vol. 13. John 1523 Edger Place Wiley and Sons, Inc. New York, NY. Sarasota, FL 34240 800-322-8666 3) Heinz, K.M. 1998. Dispersal and dispersion 941-377-3633 fax of aphids and selected natural enemies in Email: [email protected] spatially subdivided greenhouse environments. Environmental Entomology. The Green Spot, Ltd. Vol. 27, No. 4. p. 1029–1038. 93 Priest Rd. Nottingham, NH 03290-6204 4) Anon. 1999. Efficacy of four biocontrol agents 603-942-8925 on the green peach aphid, Myzus persicae, in 603-942-8932 greenhouse peppers. Midwest Biological 603-942-5027 voice mail Control News. January–February. p. 7. Email: [email protected]

Harmony Farm Supply Biological Control Suppliers 3244 Hwy. 116 No. F Sebastopol, CA 95472 A-1 Unique Insect Control 707-823-9125 5504 Sperry Dr. 707-823-1734 fax Citrus Heights, CA 95621 Email: [email protected] 916-961-7945 http://www.harmonyfarm.com 916-967-7082 fax Email: [email protected] Hot Pepper Wax, Inc. http://www.a-1unique.com 305 Third St. Greenville, PA 16125 ARBICO Inc. 888-667-3785 PO Box 4247 CRB 724-646-2302 fax Tucson, AZ 85738 Email: [email protected] 800-SOS-BUGS http://www.hotpepperwax.com 520-825-2038 fax Email: [email protected] Hydro-Gardens, Inc. http://www.arbico.com PO Box 25845 Colorado Springs, CO 80932 Beneficial Insectary 719-495-2266 14751 Oak Run Rd. 719-531-0506 fax Oak Run, CA 96069 http://www.hydro-gardens.com 800-477-3715 530-472-3523 fax International Technology Services Inc. Email: [email protected] PO Box 19227 http://www.insectary.com Boulder, CO 80308-2227 303-473-9141 303-473-9143 fax Email: [email protected]

// GREENHOUSE IPM: SUSTAINABLE APHID CONTROL Page 5 IPM Laboratories Olympic Horticultural Products PO Box 300 PO Box 1885 Locke, NY 13092-0099 Bradenton, FL 34206-1885 315-497-2063 800-659-6745 315-497-3129 Fax 888-647-4329 fax http://www.ipmlabs.com Email: [email protected] http://www.hortnet.com/olympic Koppert Biological Systems 2856 Main St. South Praxis Ann Arbor, MI 48103 2723 116th Ave. 313-998-5589 Allegan, MI 49010 313-998-5557 fax 616-673-2793 http://www.koppert.nl/english/index.html 616-673-2793 fax Email: [email protected] M&R Durango, Inc. http://www.praxis-ibc.com PO Box 886 Bayfield, CO 81122 Rincon-Vitova Insectaries, Inc. 970-259-3521 PO Box 1555 970-259-3857 fax Ventura, CA 93002 http://www.goodbug.co 800-248-2847 805-643-6267 fax Mycogen Crop Protection Email: [email protected] 5501 Oberlin Dr. http://www.rinconvitova.com San Diego, CA 92121 800-745-7476 SePRO Corp. 619-453-9089 fax 11550 N. Meridian St., Suite 180 Email: [email protected] Carmel, IN 46032-4562 800-419-7779 Mycotech Corp. 317-580-8290 fax PO Box 4109 Email: [email protected] Butte, MT 59702-4109 http://www.sepro.com 800-383-4310 406-782-9912 fax Soil Technologies Corp. Email: [email protected] 2103 185th St. Fairfield, IA 52556 Natural Pest Controls 800-221-7645 8864 Little Creek Dr. 515-472-6189 fax Orangeville, CA 95662 Email: [email protected] 916-726-0855 http://www.lisco.com/soiltech 916-726-0855 fax Email: [email protected] Stoller Enterprises, Inc. http://www.natural-pest-controls.com 8582 Katy Freeway, Suite 200 Houston, TX 77024 Nature’s Control 800-539-5283 PO Box 35 713-461-4467 fax Medford, OR 97501 800-698-6250 Thermo Trilogy Corp. 541-899-9121 fax 9145 Guilford Rd., Ste. 175 Email: [email protected] Columbia, MD 21046 800-847-5620 301-604-7015 fax http://www.thermotrilogy.com

// GREENHOUSE IPM: SUSTAINABLE APHID CONTROL Page 6 Wellmark International 1000 Tower Lane, Suite 245 Insect drawings courtesy of Hercules Bensonville, IL 60106 Powder Company; Wilmington, DE- 800-842-3135 630-227-6065 fax Handbook of the Insect World 60p.

Whitmore Micro-Gen 3568 Tree Court Ind. Blvd.

St. Louis, MO 63122 800-777-8570 The electronic version of Greenhouse IPM: Sustainable Aphid Control is located at: By Lane Greer http://www.attra.org/attra-pub/gh- NCAT Agriculture Specialist aphid.html June 2000

The ATTRA Project is operated by the National Center for Appropriate Technology under a grant from the Rural Business-Cooperative Service, U.S. Department of Agriculture. These organizations do not recommend or endorse products, companies, or individuals. ATTRA is located in the Ozark Mountains at the University of Arkansas in Fayetteville at P.O. Box 3657, Fayetteville, AR 72702. ATTRA staff members prefer to receive requests for information about sustainable agriculture via the toll-free number 800-346-9140.

// GREENHOUSE IPM: SUSTAINABLE APHID CONTROL Page 7 Appendix I: Beneficial Organisms

Organism Supplier Pests Controlled Application/Comments

AmblyseiusChrysoperla degeneransspp. or Intl.M&R Technology Durango, aphidssee above (predator)Iphiseius degenerans Services,Florikan, IPMGreen Labs., Spot (predatory mite) Green Spot

AphidiusColeomegilla colemani imaculata Florikan,Arbico IPM Labs., aphids, caterpillars, 1/sq.Release.5-2/sq. ft.; shipped yd.; as humiditylarvae and should eggs. be 70-85%, temp. 65-77°F. (pink(parasitic ladybird wasp) beetle) Harmony Farm mites, scales, thrips, Release at first sign of pests and for 3 consecutive weeks Supply, Praxis, whiteflies thereafter. Sensitive to pesticides. Rincon-Vitova, Green Cryptolaemus montrouzieri Arbico,Spot Caltec, Intl. aphids, mealybugs, 2-5/infested plant; humidity should be 70-80%, temp. 70-80°F. (predator beetle) Technology Services, soft scales Larvae are cannibalistic; repeat as necessary for control; do not Aphidius matricariae Arbico,IPM Laboratories, Hydro- aphids 500-3000/A. wear white while Can bedistributing. used in greenhouses all year long. (parasitic wasp) Gardens,Natural Pest Green Controls, Spot Nature’s Control, Aphidoletes aphidimyza Nature’sFlorikan, Control, Harmony aphids 1-3/10 sq.ft.; humidity should be 50-90%, temp. 60-80°F. Release (predator midge) FarmIntl. Technology Supply, Hydro- when aphids are first observed; release lower numers for Services,Gardens, IPMPraxis, Labora- Rincon- preventive control; apply every two weeks. Active at night; Vitova,tories, Hydro-Gardens, Green Spot sensitive to daylength. Arbico, Praxis, Rincon- Deraeocoris brevis GreenVitova, Spot Harmony Farm aphids, whiteflies, (predator) Supply, Green Spot thrips

ChrysopaDiaretiella carnea rapae NaturalArbico, PraxisPest Controls , aphids aphids, caterpillars,Release 1 lacewing/5-30 rates vary. aphids; 1000 eggs/200 sq. ft. Apply every 1-3 (predator)(parasite) Beneficial Insectary, mealybugs, scales, weeks as needed. May arrive as eggs, immatures, or adults. Caltec, Arbico, A-1 spider mites, thrips, Harmonia axyridis GreenUnique Spot Insect Control, scale, whiteflies whiteflies, Temps. should be 70-85°F; humidity around 70%. (Asian lady beetle) Praxis, Rincon-Vitova, mealybugs, aphids Hydro-Gardens Hippodamia convergens A-1 Unique Insect aphids, mites, Release at dusk near an immediate food source. Spray plants Chrysoperla (lady beetle) rufilabris (predator)Arbico, Control, Beneficial Arbico, seewhiteflies above with water prior to release. (predator) Caltec,Insectary, IPM IPM Labora- Labs., A-1tories, Unique Natural Insect Pest Controls,Control, Nature’s Nature’s Control, HarmonyPraxis, Farm Rincon-VitovaSupply, Hydro-Gardens, Praxis, Green Spot Organism Supplier Pests Controlled Application/Comments

Iphiseius degenerans or Intl. Technology aphids Amblyseius degenerans Services, IPM Labs., (predatory mite) Green Spot

Lysiphlebus testaceipes Praxis aphids (parasitic wasp)

N. cucumeris and N. barkeri Hydro-Gardens thrips, aphids, mites 1 predator/sq. ft.; humidity should be moderate, temp. 70°F. Establish population early. Repeat every month during periods of warm, dry weather.

Orius insidiosus Florikan, IPM aphids, caterpillars, 1/10 sq. ft. (preventive), 1 every 2 sq. ft. when pests are (minute pirate bug) Labs., Harmony Farm thrips, whiteflies, present. Temperature should be 70-90°F. Orius are (predator) Supply, Arbico, mites dormant September–April. Re-apply every 2-3 weeks. Hydro-Gardens, Very susceptible to pesticides. Works well in combina- Praxis, Koppert, tion with Neoseiulus cucumeris. Intl. Tech. Services, Green Spot

Propylea quatuordecimpuncata Praxis aphids (predatory beetle) Appendix II: Biorational Pesticides

Azadirachtin – extract of neem seed; IGR that works through contact or ingestion