Be on the Look-out for Garden Pests

Krista Harding
District Extension Agent, Horticulture
Southwind Extension District
111 S. Butler
Erie, KS 66733
Office: 620-244-3826
Cell: 620-496-8786


This spring brought an increased interest in gardening. Now that the gardens are planted and things are beginning to grow, gardeners should be on the look-out for insect pests.

If you are having difficulty with insect, the first thing you need to do is determine exactly what insect pest you are dealing with. To figure this out, start by looking at the type of damage being caused to the plant.

Most pests that feed on vegetable plants have either chewing or sucking mouthparts which each produce different types of feeding damage. For example, insect pests with chewing mouthparts feed on leaves, stems, flowers, fruits and roots. They physically remove plant tissue while feeding. This type of pest will often leave physical evidence of their feeding as well – such as the tomato horn worm.

Insect pests with sucking mouthparts feed on plant juices causing stunting, wilting, leaf distortion and leaf yellowing. An example of this is aphids. They also leave behind physical evidence in the form of honeydew – a clear, sticky substance on plant surfaces.

Scouting plants for insects is an important part of gardening and should be done often. I know many gardeners browse through their plants every day and that is great! It is important to find insect pests as soon as possible. Inspect the top of the leaves as well as the underside of the leaves. The underside is where most insect pests will be found.

Once pests are found, again it is very important to get them correctly identified. Caterpillars, beetles and bugs can be removed from plants quickly and easily by handpicking and then placing them into a container of soapy water. Aphids and mites can actually be dislodged off of plants with a forceful spray of water.

Pesticides can also be used and those labeled for vegetable gardens work in one of two ways – they either kill insects on contact or act as stomach poisons. But again, you need to know what insect you are targeting before application of chemical control. Many times, at the first sight of a pest, gardeners get excited and search the cabinet for some type of product to use. This is not the best approach to take! Beneficial insects can be killed using this tactic.

Speaking of beneficial insects, they actually prey on other insects and mites. Examples include parasitic wasps, ladybird beetles and green lacewings. Beneficial insects can even be encouraged to remain in a garden area by planting specific plants to attract them. The plants need to be placed in or around the perimeter of the garden. Examples of plants include dill, fennel, coneflower, yarrow and garlic chives.

If gardeners do not want to used pesticides, there are other practices to keep insect pressure down in the garden. Healthy plants are less likely to be attacked by insects. Plants that receive too much or too little water are more susceptible to insect pests. The same is true for fertilizer use – too much or too little will cause problems. Keep weeds down too as weedy areas are just a good place for aphids, mites and leafhoppers to congregate.

As you scout for insects in the garden, if you come across one that you cannot identify, the Extension office can help! Insects can be brought into one of our four office locations or pictures can be e-mailed. Remember, it is very important to know what pest you are targeting before pesticides are used.

Krista Harding is a K-State Research and Extension Agricultural agent assigned to Southwind District. She may be reached at [email protected] or 620-244-3826.

K-State Research and Extension is an equal opportunity provider and employer.

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