Scouting your plants is an important part of managing pests in your plants. Scouting is often overlooked, but it will help you determine what is out there and if you need to make any type of action to manage any pests that are present.
One thing to consider is are there enough pests for it to be worthwhile to treat and is the damage they are causing going to be detrimental? For example, if you have some pests eating your tomato leaves you can wait longer to control them compared to if they are eating the fruit. Some ornamentals may be in a more visible location (by the front door) where damage is less tolerable than to plants in other areas (in the backyard tucked away in a seldom used corner).
There are two main ways that you can scout for pests in your plants: trapping and visual inspection.
There are a couple of different ways trapping can be done. One way is by using sticky cards. These will catch anything and everything (non-selective). As the name implies, sticky cards are covered in a stick substance that will trap stuff that lands on them. Some examples of this are fly paper, or you can purchase cards that are yellow or blue. Colored cards will attract insects such as aphids and whiteflies, making it easier to spot them.
Trapping can also be done by baited lures, these are usually used if you want to monitor for a specific group or species of insects.
Visual inspection requires looking at the plant itself for pest problems. Look on the undersides of leaves (insects often feed and hide here), terminal shoots, and buds and flowers as many types of insects like tender plant material. If you use sticky cards you can use them to help with your visual inspection and determining the populations of pests.
After you have gone out and looked in your garden or landscape at the pests, you need to figure out what they are. Pest identification is important because it will help determine potential management techniques. Some pests may not cause much damage and management may not be warranted if they are found. Others can cause quite a bit of damage and will need to be managed. In some cases, the issues you are seeing may not be pest damage at all. Properly identifying pest will help determine what kind of management strategies should be used or if any are even needed.
If you need help determining what a pest is or if it’s something you need to think about managing, you can bring samples into any of our extension offices. You can also send samples to the University of Illinois Plant Clinic. Their website can be found at web.extension.illinois.edu/plantclinic. There you will find instructions on how to submit samples as well as any fees that may apply.