Getting Started with IPM

Now you're clear on what IPM is—and why it's vital to a thriving garden, or landscape, or farm. You're ready to get IPM-ing. But where do you start? There are five main components to a successful IPM program¹:

 

1. Pest identification
2. Field monitoring and population assessment
3. Control action guidelines
4. Preventing pest problems
5. Integrating biological, chemical, cultural, and physical/mechanical management tools

 

Why Pest Identification Is Important

Let's start at the beginning—pest identification. Pest identification can be intimidating. Why is it important? Suppose you find a new insect on your peach tree. As an IPM trainee, you know that not all insects are “bad,” and that some are actually beneficial. Your insect is brown, shield-shaped. You will need to identify it in order to determine whether it is an invasive Brown Marmorated Stink Bug or a beneficial Spined Soldier Bug, and whether you should squash it, or leave it in peace. Or if you're able to identify the fungus on your grass as Dollar Spot, you may decide to apply nitrogen and adjust your irrigation instead of just applying fungicide. When you can identify all the factors contributing to disease, you will be able to make management decisions that support the overall health of your plant, enabling it to defend itself better against predators and disease. And of course, without accurate identification of your pest, your treatment may be a waste of your time and resources.

 

What Is a Pest?

The definition of pest seems obvious, until it isn't. My students are often surprised when they learn about the many uses of our “weeds,” both as food and medicine. It's often said, “A weed is a plant out of place.” If you think about it, a “weed” is defined by human needs and wants. Pests, likewise, can be defined as “organisms that reduce the availability, quality, or value of a human resource”¹. In other words, if they mess with our stuff, they are a pest. Any organism could be considered a pest, given the right conditions. These organisms are often important members of the ecosystems they inhabit. IPM encourages us to look into our hearts and wallets and consider what amount of pest damage we are willing to tolerate, and to make educated control decisions that will have the least impact on the other organisms with whom we share the planet. Do we need to be able to continue growing oranges and lettuce and broccoli? Definitely. Do we need to kill every last aphid in our garden? Maybe not.

 

How to Identify Pests

Now it's time to put on your pest detective hat. But where do you start? I've found there are a few key details that can narrow down your pest search considerably:

 

• Host plant
• Site conditions (recent changes, humidity, temperature, weather, time of year, soil conditions)
• Symptoms (changes in plant appearance)
• Signs (physical evidence of the pest: bacterial ooze, fungal fruiting bodies, frass/insect poop)

 

Most pests require specific foods and conditions in order to survive. Because of this, knowing which plant species is being affected is a vital first step in identifying your pest of interest. For example, it is easy to confuse a pine beetle and an invasive shot hole borer (ISHB), but since they have different hosts, knowing what tree it was found on can help you narrow down the possibilities.

 

 

 

Resources for Pest Identification

There are a number of resources online to help with pest identification. “.edu” educational websites can generally be relied upon to have good, science-based information, as can the USDA.

 

In California, the University of California Agriculture and Natural Resources (UC ANR) UC IPM website is the go-to reference for anyone practicing IPM. The information they've compiled is thorough, science-based, and specific to the plants and pests of our region. Their website has an entire tab dedicated to identifying and managing pests. Narrow your search based on your pest's location (Home, Garden, Turf and Landscape, Agriculture, or Natural Environment). From there, you can narrow your search by plant species or pest category.

The UC IPM Weed Photo Gallery has tutorials on identifying and distinguishing broadleaf weeds, grasses, and sedges.  It also provides two weed identification keys. What is an identification key, you ask? An identification key is essentially the Choose Your Own Adventure of IPM. For those of you who are too young for that reference, the key will usually give you two choices. Does it have two+ leaves per node? Go left. Does it have one leaf per node? Go right. Are the stems square? Go left. Are the stems round? Go right. Eventually, by process of elimination, if you don't make any wrong turns, you will arrive at your weedy destination. For a really good time, check out the Purdue Extension Pictorial Key to the Order of Adult Insects. The UC IPM Plant Problem Diagnostic Tool can also be helpful to narrow down more elusive plant issues.

*Grass and Identification Key images courtesy of UC IPM.

 

Obviously, pest identification is a larger subject than I can address in one blog post. Hopefully I've at least gotten you pretty excited to explore the UC IPM website, and to start testing out your identification prowess. And if you're struggling with a pest that you just can't identify, or want specific help with IPM in your own garden, you can contact a Master Gardener volunteer at mgsanbern@ucanr.edu.

 

Author info:

Gretchen Heimlich-Villalta is an ISA™ certified arborist who has been a San Bernardino County Master Gardener since 2014. She received her AS in Integrated Pest Management from Mt. San Antonio College, where she has helped teach IPM since 2020. She received BA degrees in Creative Writing and Photography, and is currently working on her Ph.D. in Plant Pathology at the University of California, Riverside, where she is researching citrus root and soil health; she also helps manage the Strub Avenue Community Garden in Whittier.

Sources:

1. Flint, M. L. IPM in Practice, 2nd Edition: Principles and Methods of Integrated Pest Management. (University of California Agriculture and Natural Resources, 2012).