Integrated pest management (IPM) is based on both science and common sense. It approaches pest control with techniques of pest prevention, pest reduction, and the elimination of conditions that lead to pest infestations. Greenhouse IPM combines preventative solutions like avoiding environmental conditions that encourage pests and wearing protective clothing with active greenhouse pest monitoring, effective pest treatment, and evaluation of treatment effectiveness.
The Basics of Integrated Pest Management
Don’t attract pests! Identify issues that could contribute to infestation such as maintenance, overwatering, sanitation, weed growth, and housekeeping, and ensure that those issues are addressed.
Keep pests out of the greenhouse. Make sure holes and cracks are sealed, that there is bug netting where needed, and that clothing and equipment do not bring in pests from the outside. Regular inspection and monitoring of the greenhouse and surrounding area is key to identifying pest and weed problems early where they can be treated much more easily.
Get rid of pests promptly. Pesticides are the last component of IPM because prevention is emphasized. Pests should always be identified and when total elimination of pests is not possible or practical, threshold limits and action levels should be determined.
Think about what you’ve done. Documentation is very important in IPM. In addition to regulatory compliance, it can be used to evaluate the effectiveness of treatments and inspection schedules, and it can help identify patterns if pest problems continue.
Monitoring Greenhouse Plants for Pests
Monitoring and trapping are needed to identify most pests and detect signs and symptoms of infestation or pathogen infection. Early detection of pests through regular monitoring ensures that if a pest is detected treatment can be applied promptly and the spread of infection or infestation is reduced.
Growers should be aware of particular pests and diseases most common to the crops they will be cultivating. Growers should also evaluate the growing area and consider if it has any traits that might encourage or harbor pests and pathogens. If seedlings, cuttings, or transplants are being brought into a greenhouse, at least ⅓ of plants should be inspected for insects and diseases.
In addition to visually inspecting plants regularly, sticky cards placed or hung around the greenhouse will trap insects and allow them to be evaluated. Blue, white, and yellow cards are available. The plastic of the trap is covered with a non-drying adhesive. The attracted insects land on the trap and are stuck. These cards can then be used to identify the pest and estimate how many there are, it is not intended to be used as a bug trap.
Yellow Sticky Cards: attracts winged aphids, leafminer adults, whiteflies, leafhoppers, thrips, various flies, and other insects
Blue Sticky Cards: used with thrips
White Sticky Cards: used with fungus gnat adults
Sticky cards are usually suspended vertically just above the tops of the plants. They can be attached to sticks or hung on a string. One to three cards per 1,000 square feet in the greenhouse is recommended. Cards should be changed weekly. Sticky cards are used just to alert you to insect infestations, trapping tools are used to reduce and manage infestations. Trapping products such as sticky tapes are also available for the management of thrips, whiteflies, leafminers, and fungus gnats.
Common Greenhouse Pests and Pathogens
Insects: Aphids, Fungus Gnats, Shore Flies, Whiteflies, Scales, Thrips, Mealybugs, Bloodworms, Mites, Leafminers
Other Pests: Nematodes, Loopers, Caterpillars, Cutworms, Armyworms, Slugs and Snails
Pathogens: Botrytis, Powdery Mildew, Pythium, Dampening Off, Bacterial Blight