Though the moniker “integrated pest management” wasn’t coined until the 1950s, IPM has been used for much longer than that. You might have been using it without even realizing. Integrated pest management basically means monitoring your crops, identifying pests, and then controlling the situation if things get too out-of-hand.
Have you ever:
- Identified the pests on your crop before deciding on the best course of action?
- Used scouts to monitor crops for pest infestation?
- Set a threshold for pest infestation, after which you would act?
- Utilized cultivars that are pest-resistant?
If so, you’ve utilized integrated pest management.
There are many definitions of IPM, but the University of California describes it as follows:
“IPM is an ecosystem-based strategy that focuses on long-term prevention of pests or their damage through a combination of techniques such as biological control, habitat manipulation, modification of cultural practices, and use of resistant varieties. Pesticides are used only after monitoring indicates they are needed according to established guidelines, and treatments are made with the goal of removing only the target organism. Pest control materials are selected and applied in a manner that minimizes risks to human health, beneficial and nontarget organisms, and the environment.”
That’s still a super dense definition. Basically, IPM is all about being proactive rather than reactive, and using data-driven decision-making when planning and executing pest management. There are many ways we can prevent pest infestations before they start. Being prepared means that even when they happen, we’re ready for them.
To go into more concrete examples of what an IPM strategy looks like, we can take a closer look at the four pillars of IPM:
Pillar 1: Monitoring
Keeping an eye on your plants is the only way to know if they’re healthy and pest-free. In many cases, this can be done by the greenhouse workers while they are tending to the plants and using sticky traps.
Yellow or blue sticky cards can be purchased through your local agricultural supplier. Inspect the cards regularly to count the number of pests on them and take note of anything that seems unusual. If you’re a vegetable/crop grower, feel free to leave the same cards up week after week until they are full or they lose their stickiness. If you’re an ornamental grower, it will be more helpful to replace sticky cards every week during the summer since pests damage threshold is lower in ornamentals. Placement of sticky cards is important. They should be placed near vents and other areas that commonly harbor pests. The traps should also be hung above the plants, they should be low enough to be able to catch pests that are weak fliers such as thrips, the recommended placement is about 15-25 cm above the crop.
Some insects don’t fly (like wingless aphids or spider mites) or are otherwise unlikely to show up on sticky cards. Other issues, such as diseases, will also not be reflected on the sticky cards. For this reason, it’s important to not rely too heavily on sticky cards -- we highly recommend a crop inspection program that includes going out in the crop on a regular basis and recording any instances of pests or disease.
Going through the entire growing area might be feasible if you’re a micro-cultivator, but for many large operations this is economically unfeasible. Instead, use random sampling to check in on a few different areas of the greenhouse, as well as entry points (where pests are likely to enter the growing area) and areas of concern (areas where you’ve seen infestations before, for example).
It’s recommended that monitoring programs are undertaken on a weekly, but if you are regular and consistent about it, then other time frames can work as well.
Random sampling - Sampling from (inspecting) a few randomly-chosen individuals instead of looking at every individual in the population. We assume* that these random individuals will be representative of the overall population.
This is a pretty big assumption, which is why you should also keep an eye on specific areas of concern.
Keep in mind that monitoring becomes much more helpful if you keep a physical record of your monitoring results: being able to compare issues in different areas or on different crops, especially in combination with season and environmental conditions, can help not only decide on the best method of control, but can also help you to predict and prevent future issues.
Pillar 2: Identifying
Identifying is a part of monitoring but is often listed as a separate foundation of IPM due to its importance. Understanding the pest life cycle and feeding behavior will help deciding which control method (biological, chemical, physical) will be the most effective.
Identifying from sticky cards
Identifying larger pests such as Colorado potato beetles is relatively easy: you can even use an app to take a photo (or browse photos listed online) to identify the pest you’re looking at. Small insects can be much harder to identify. Sticky cards are helpful in keeping trapped insects still if you’d like to use a loupe to try and identify the pests, but we can often skip the loupe and identify the pest based on other clues on the plant, including specific patterns of damage. For example, spider mites leave tell-tale webs on plant foliage, so it’s not usually necessary to look at the mite under a microscope to tell that you have a spider mite infestation on your hands. If you’re stuck, try searching online for common pests found on the crop you’ve identified as being damaged, and see if anything looks familiar. When all else fails, consider reaching out to a local IPM or biocontrol company for assistance - many will offer IPM or consultation services.
Once you have identified the pests, you will be better able to choose a strategy to control them. Both pesticides and predatory insects can be pest-specific: following our previous example, once you have identified the pest as the two-spotted spider mite, you can skip the generalized insecticides and use a miticide or a predatory mite like Phytoseiulus persimilis, which only eats spider mites. Additionally, knowing the specific pest will allow you to find out more information that will help you in the control step:
- Where on the plant they live and lay eggs (where to spray pesticides or apply beneficial insects)
- Dispersal patterns (how they move and spread throughout the greenhouse)
- Lifecycle (how quickly they might spread, how frequently to apply bios, etc.)
- Damage potential
- Possibility of resistance to pesticides or other control techniques
Pillar 3: Controlling
This is the part that everyone wants information about - how do I control pests and disease in the greenhouse? Especially if you’re used to relying on generalized pesticides for pest control, it can be difficult to make the switch over to a more varied pest control strategy. Since there are many types of control and a lot to go into, the control aspect of IPM will be covered in more depth in next week’s article. Tune in then for more details!
Pillar 4: Evaluating
A key component of IPM is evaluating how well our control methods worked. Depending on the type of pest, timing within the season, and type of crop, there are different indicators you can compare in order to evaluate how well your pest control strategy worked, including the following:
- Damage to foliage and fruit
- Number of plants infested/damaged per unit area
- Population of pest per unit area
- Damage to harvested crop
- Commercial yield
The scouting reports and data you’ve collected will be helpful here. Make sure to scout thoroughly before and after using control measure for effectively evaluating how well those strategies worked.
It is also beneficial to take note of all related costs of the chosen pest management strategy.
- How much did biocontrol agents and selective pesticides cost?
- Were there any labor costs in applying or deploying the control method?
- Was there time lost to waiting for the greenhouse to be safe to enter after chemical pesticide usage?
- Did your biocontrol supplier provide the bios with no delays? Were the natural enemies active on arrival?
These are all questions that can help you evaluate how effective and economical the pest control method used was.
Finally, you may want to write a short report noting down anything that isn’t reflected in the data you’ve collected. For example, you can talk about how it took longer to spray pesticides than you were expecting, or that the beneficial insects you purchased seemed to be less effective during heat waves. It is easy to forget these details, especially if your pest control strategies work and a significant amount of time passes before we encounter the same pest again.
There are many different layers and components to integrated pest management, all of which are helpful in different situations and for different growers. Keep in mind that you don’t need to use all of the various IPM strategies out there (tune in next week for our article on IPM control methods!) You may wish to try out just one or two methods, or slowly phase in a set IPM program. That being said, you’ll have the most success if you stick to the pillars of IPM: monitoring, identifying, controlling, and evaluating. This cycle will allow you to use data-driven decision making to choose the pest control methods that are most effective, most economical, and, ideally, best for both your operation and the environment.