Some insects are good for your yard, lawn or garden, while others can cause damage that results in decay and death of vegetables, flowers or shrubs. Understanding how to identify the signs of destructive garden pests enables gardeners and homeowners to take immediate steps toward eradicating the problem through natural or chemical means. Signs of destruction or infestation vary depending on the type of pest and degree of infestation. Such signs may be visible on leaves, stems or fruit, while others are found near or on roots. Sometimes pests can be identified by churning up the soil near plants, while others are larger, like gophers, squirrels and mice.
Inspect your plants for holes in the leaves on a weekly basis. Caterpillars, grasshoppers and borers can damage leaves and flowers. In most cases, you'll see chewed edges of leaves, holes in fruit or damage to flowers. Holes in leaves or flowers may be perfectly round and located in the center of the leaf or closer to the edge.
Watch the leaves for signs of brown or rust-colored spots, often caused by insects like the corn earworm or the Japanese beetle. These pests leave telltale signs behind as they slowly work their way through the garden. Spots may be the size of a pinprick or the size of a pencil eraser. In some cases, the spots may be sporadic and occasional, or they may appear connected or clumped on one side of the leaf or another.
Inspect your plants and flowers for signs of grasshopper damage. Grasshoppers will chomp through leaves, stems and stalks throughout the summer, but most of their damage will occur in late summer as their population grows. Grasshoppers leave nothing of the leaf behind, whereas caterpillars consume the juiciest parts of a leaf and then move on to another.
Carefully inspect the roots of the plant if you see it wilting for no apparent reason. Beetles and borers often attack roots as they work their way into a plant. Inspect the base of stems where the they attach to the root crown. Often new growth will look chewed, stunted or brown, or have oozing sap.
Look for signs of eggs or larvae on the underside of leaves of vegetables, fruit trees or flowers. Insects like whiteflies, spider mites and aphids leave clusters or clumps of larvae in plain sight on the undersides of leaves or along a stem. Mealybugs leave behind clumps of white, cottony sacks, while caterpillars and foliage worms leave behind tiny black dots. Scales appear as small, rounded, brownish bumps on the stalk or stem of a plant.