Pests with chewing mouthparts eat portions of the plant. They may defoliate the plant by eating all the leaves. Pests with sucking mouthparts usually cause the plant to discolor or twist and curl. Many plants react to the saliva and damage of sucking pests by causing the foliage to curl or the young stems to twist. Locating an actual specimen of the pest makes diagnosis easier.
Many pests stay on the plant at all times and a close inspection is all that is necessary.
Carefully approach the plant low to the ground and try to observe the plant's upper and lower leaf surfaces without casting a shadow. Many pests come out at night and you will have to look for these with a flashlight. If you have located a suspected pest and you cannot identify it from the illustrations included here, try to capture a specimen and take it to your county's Extension office. Most pests can be placed in a dry jar or plastic bag. A dry tissue or paper towel placed inside the jar or bag will keep the specimen dry.