Pest management can be one of the greatest challenges to the home gardener. Careful identification of the problem is essential before control practices can be used. Some insect damage may appear to be a disease, especially if no visible insects are present.
Insects damage plants in several ways. The most visible damage is chewed plant leaves and flowers. Many pests are visible and can be easily identified, including Japanese beetle, Colorado potato beetle, and numerous species of caterpillars such as tent caterpillars and tomato hornworms. Other chewing insects come out at night to eat and burrow into the soil during the day such as cutworms. These are much harder to identify but should be considered if young plants seem to disappear overnight or are found cut off at ground level (this could also be rabbit or deer damage).
Sucking insects are extremely common and can be very damaging. These insects act like mosquitos or ticks and suck the nutrients out of the plant. They also can carry diseases from plant to plant. Often the younger leaves will appear curled or puckered. Look on the underside of the leaves, which is where these insects tend to gather.
Other insects cause damage by boring into the stems, fruits, and leaves. They may disrupt the plants ability to transport water. Common examples of boring pests include squash vine borers and corn borers. A telltale sign is the presence of sawdust like material on plant stems and fruits.
Pesticides are widely used in home gardens and lawns. Their improper handling and application can cause a number of health and environmental problems. Birds, beneficial insects, and earthworms are a few organisms that can be affected by improper use of pesticides. Besides normal chemical treatments there are a number of organic products that are less harmful.
The best way to treat insects is by building a healthy garden so that you do not get the insects to begin with. Add organic matter to your garden such as compost and composted manure to create beneficial bacteria. Also do not plant the same crop in the same place each year. Overcrowding causes weak growth because the plant often has to grow taller to “reach” for the light it needs. Over fertilizing can also cause too much growth and attract sucking insects such as aphids and mites.
If all of this fails and you have to treat with a pesticide, just make sure you are careful not to harm other beneficial insects such as bees, ladybugs, and butterflies. As always if you have questions don’t hesitate to talk to your local nursery professional.