18 Common Garden Pests

Let's face it - there isn't a gardener or farmer who hasn't come across one of these pests, while working in their organic garden. By finding out more about these insects and ways to control them, it is possible to grow healthy, abundant crops, and keep your garden healthy!


Aphid : Aphids passively feed on sap of phloem vessels in plants, as do many of their fellow members of Hemiptera such as scale insects and cicadas. Once a phloem vessel is punctured, the sap, which is under high pressure, is forced into the aphid's food canal.

Army worm : Its name is derived from its feeding habits. They will eat everything in an area and once the food supply is exhausted the entire "army" will move to the next available food source.

Asparagus Beetles : After emerging from "overwintering," the beetles begin to eat the young shoots and tips of the asparagus plant. This usually occurs somewhere around early to mid-April, depending on the region's climate. Once they have nourished their bodies, they will begin the process of laying eggs. In about 3-8 days, the eggs will hatch and the larvae will emerge. They start to eat the tips of the tender asparagus plantings. Upon maturation in about two weeks, the larvae will descend to the soil and build cocoons where they will undergo pupation in about a week or so. The adults then emerge from these chambers and then the life cycle process starts all over again.

Bagworms : In the spring, the bagworm eggs hatch and each larva leaves the bag by releasing a thin silk thread and floating down out of the bag. The wind will then carry it to another host plant, where it will attach and start creating its own bag. Using pieces of leaves, twigs, and plant debris, it will construct the bag and attach it to a branch of the host plant. This larva will continue to feed on the host plant, and in turn, continue to add to the material surrounding the silk sack. The larva may move its sack to another spot on the plant or to another host plant if it prefers.

Cabbage Loopers : This species is very destructive to plants due to its voracious consumption of leaves. It is not restricted to cole crops; other plant hosts include tomato, cucumber and potato.

Cabbageworms : It lives on and feeds on various plants of the cabbage family throughout gardens and farmlands in its range.

Colorado Potato Beetles : Colorado beetles are a serious pest of potatoes. They may also cause significant damage to tomatoes and eggplants. Both adults and larvae feed on foliage and may skeletonize the crop.

Corn Earworms : also known as the Tomato Fruitworm, is the most devastating pest of corn in the U.S. Although the corn earworm's favorite food is corn, it will also eat tomatoes and cotton.

Cucumber Beetles : When the adult cucumber beetle emerges from overwintering, after finding food, it will lay eggs in the dirt next to plantings which can then be used by the larvae for nourishment once they hatch in about ten days. Larvae will feed on the roots and stems of the plantings for 2-4 weeks and then pupate. In another two weeks, they will emerge as adults.

Cutworm : they are moth larvae that hide under litter or soil during the day, coming out in the dark to feed on plants. A larva typically attacks the first part of the plant it encounters, namely the stem, often of a seedling, and consequently cuts it down; hence the name cutworm.

Fungus gnats : They are typically harmless to healthy plants - and humans - but can inflict extensive damage to seedlings; their presence can be indicative of more serious problems. In houseplants, the presence of fungus gnats may indicate overwatering; they may be feeding on roots that have sat in drain water too long and are thus rotting, or the gnats may be attracted to fungus growing in saturated topsoil. Consequently, allowing the soil to dry may reduce their numbers.

Grasshoppers : They can be found throughout North America in gardens, fields, woodlands, and basically any other area with vegetation. Because they can live and travel to a variety of areas in search of food, they can be difficult to control. If one area doesn't suit them, they can simply go to another garden or field until they find one they prefer. Even if you get rid of the present population in your garden or field, others may follow in a short while, causing frustrations for gardeners and farmers alike.

Harlequin bugs : They spend the winter hidden under plant debris, then, after emerging in the spring, females will lay their eggs. Eggs are laid in two-row clusters on the underneath parts of leaves. When she has finished, the female will have laid about 150 eggs. The female will fiercely defend her eggs from predators. Within three weeks, the eggs will hatch and the emerging nymphs will begin feeding on the host plant. Nymphs feed for about two months and progress through five instars until they become adults.

Japanese Beetles : Japanese Beetles are voracious leaf-feeders and cause damage to a large variety of plants in a homeowner's lawn, landscape and garden.

Leafhoppers : They drink the juices of fruits and vegetable plantings, they can cause a variety of symptoms and problems.

Mealybug : The females feed on plant sap, normally in roots or other crevices. They attach themselves to the plant and secrete a powdery wax layer (therefore the name mealybug) used for protection while they suck the plant juices. The males on the other hand, are short-lived as they do not feed at all as adults and only live to fertilize the females.

Psyllids or jumping plant lice : They can be found throughout the world and live mostly on woody plants and certain fruit trees and vegetable crops, including pears, tomatoes, eggplants and peppers.

Whiteflies : Adult whiteflies are extremely small insects with white wings. If bothered, they may rise in what appears to be a cloud of dust. Whiteflies, in both the nymph and adult stages, feed on plants by sucking juices from the plant tissue. As a result, an infected plant may not appear to be fully developed.