The do’s and don’ts of integrated pest management

Despite their best intentions, growers sometimes take actions that make pest problems worse, says Matt Kispert, horticulturist at CropKing. For instance, take when they wear bright colors. “You don’t want to look like a giant flower every time you go in and out of your greenhouse – you’re going to be attracting the pest insects you’re trying to keep out.”

To help growers successfully battle these pests, Kispert shares the “do’s and don’ts” of integrated pest management.

Do: Educate yourself about the problem pest.

Growers should learn about the insects they are dealing with, by learning about their habitats, characteristics and the stages of their life cycles, Kispert says. Being able to interrupt the life cycle is one of the key components of pest management. “Certain insecticides will target certain instars, certain beneficial insects will only prey upon different life stages,” he says. “Knowing how long it takes the pest insects to go through those life stages is important, because it gives you an idea of how often you need to do your applications.”

Don’t: Repeat the same scheduled spray with one insecticide.

Spraying the same insecticide at predetermined intervals is a dated approach, Kispert says. “The old, easy way of going about it was spraying your field or your greenhouse on a set schedule, and all that does is reinforce the insects into developing resistances,” he says. "It doesn’t really target them as effectively as you could if you took the time to learn a little bit more about the pests that you’re dealing with.” Growers should avoid making more than three applications of an insecticide with a hard-wired mode of action without rotating something else in.

Do: Rotate insecticides.

Various insecticides belong to many defined Insecticide Resistance Action Committee (IRAC) categories, or modes of action, Kispert says. “It’s really important to rotate between those categories when you’re doing applications, because the pests will develop resistances to a specific category if you continuously use that same category.” Even if a grower is rotating between different chemicals, the pest can still develop a resistance if those chemicals are in the same group.

Don’t: Allow unwanted pests in.

Problem pests can make their way into the greenhouse in several ways, Kispert says. These include allowing several people to walk in and out of the greenhouse at the same time, thus keeping the doors open for extended periods; wearing bright colors when entering and exiting, which attract insects; bringing in pet plants for the winter that could potentially carry pests with them; and planting flowers outside the greenhouse. When growers keep plants around the outside of the greenhouse, particularly near vents and exhaust fans, insects are more likely to be drawn to it and make their way in. “A lot of growers will either use gravel or mulch just to [surround] that perimeter,” he says.

Do: Keep records.

Growers should keep records of numerous data, such as where in the greenhouse pests are appearing, how they are responding to certain control methods and average high and low temperatures in the area, Kispert says. “That sort of historical data will be useful for the following season, because if you routinely notice that your first instance of a pest is occurring in a specific spot in your greenhouse at a specific temperature, like once the weather starts to hit these certain temperature regimes, then you can respond to that ahead of time,” he says.

Do: Check sticky cards.

Sticky cards are for monitoring purposes, not for reducing the insect population, Kispert says. He has seen growers who think they can leave their sticky cards unchecked. “You go out there and you see them and these things are sun-bleached and completely covered corner to corner in bugs because they’ve been in there for months without being indexed,” he says.

Don’t: Wait to respond.

Many floriculture growers talk about economic damage thresholds, which Kispert says refers to the amount of pest damage a grower can allow before they should act. “It doesn’t really work like that in a vegetable greenhouse, because once those things are in, they’re going to start reproducing so rapidly that they’re going to surpass that threshold very quickly if you don’t respond appropriately,” he says.

Do: Talk to fellow growers in the area.

Communicating with other local growers about their pest issues will provide insight into what is causing, or could cause, headaches, Kispert says. “I was in Iowa – I never had any issues at all with whiteflies – I didn’t see a single whitefly for the three years I was out there,” he says. “But if you go in the Carolinas, there’s a ton of whitefly issues. Communicating with the growers in your area and getting an idea of what you’re in for will prepare you with how you should go about setting up monitoring systems.”

Photo: iStock.com