44 Common Garden Pests

Many types of bugs see your garden as a big, free buffet. At first, you may not know there are bugs eating your plants until you find sunken, brown spots on your apples or see tiny, white insects flying around your tomato plants. Holes in leaves, small grubs around the roots of container plants, speckled foliage and skeletonized leaves are just a few signs of garden pests.

The best offense is a good defense. Check your plants often and act as soon as you spot a problem. Some types of bugs can be deterred by knocking them off with a spray of water from your hose. Banish other pests without chemicals, use good organic gardening practices or hand-pick and discard large bugs. Read on to learn how more about common garden pests.

The tiny mites live under leaves and suck sap, causing yellow mottling. Fine webs are sometimes visible. Raise humidity and use a biological control under glass. Otherwise try organic sprays.

These microscopic mites suck sap and cause abnormal growths. These include raised pimples or clumps of matted hairs on leaves, or enlarged buds. Most are harmless and can be tolerated.

Bagworms are the larval form of a moth that attacks evergreens and other trees. The worm inside each bag feeds on the evergreen bush or tree, building a case around itself for protection from predators. The case is made from bits of the plant the insect is feeding on and slowly enlarges over time as the insect grows. Females lay eggs in the bags in late fall. The best control, if you only have a few bagworms, is to handpick the bags and drop them into soapy water or put them out with the trash. Predatory insects including wheel bugs or insect-eating birds will attack these insects, even inside their bags. You can also spray traditional or bioinsecticides. Follow directions carefully on timing. Once larvae are more mature and tucked into thicker bags, the chances of a spray reaching the worm itself are small.

Japanese beetles aren't picky about what flowers they chew and even attack the otherwise pest-proof purple coneflower.

Leaf miners create discolored blotches or surface trails on leaves. Most leaf miner damage is relatively harmless and can be left untreated.

To avoid maggots in apples, spray emerging caterpillars twice using bifenthrin, starting in midsummer. Also hang pheromone traps in late spring to catch male moths and prevent them from mating.

In spring, the leaves of fruit trees are webbed together and hide green caterpillars inside. Holes are visible when leaves expand. Apply sticky traps to capture adult moths.

Aphids leave a sticky substance called honeydew on plants, which can allow black fungus to grow.

Tiny blister or shell-like bumps on leaf backs result in poor growth. Other symptoms are sticky excretions and sooty mold on evergreens. Wash off mold, and spray with horticultural oil.

Under glass, hang yellow sticky pads to trap the tiny white flying adults, which suck sap from plants; use a biological control (Encarsia wasp) on larvae or spray with organic chemical controls.

Both the adults and larvae eat holes in the leaves, mainly on Viburnum tinus and V. opulus; this can slow growth and looks unsightly. Spray badly affected plants in spring with bifenthrin or thiacloprid.

This tiny black sap-sucker, known as "thunder fly," causes white patches on the petals and leaves of indoor plants, and also peas, leeks, onions and gladioli. Use biological controls.

Small cream grubs with a brown head feed on plant roots, especially those growing in containers or with fleshy roots. This can cause plants to suddenly collapse.

The adult beetle is nocturnal, flightless and makes notches in leaves. Use a biological control (nematodes).

These voracious eaters decimate brassicas and nasturtiums. Rub off egg clusters and pick off any caterpillars you find.

The tomato moth damages fruits. Pick off any caterpillars you find.

A rose slug is the larvae or immature stage of a rose sawfly. It's easy to overlook on roses, until its feeding begins to damage leaves. Rose slugs feed on leaf undersides, out of sight, nibbling on leaf tissue — the part between the veins. When they're done eating, leaves resemble skeletons. Usually when gardeners spot rose slug damage, they think their roses have a disease because leaves are speckled and have holes in them. Sawfly larvae are not slugs or caterpillars, but a different type of critter. Blast them off roses with a spray of water, or spray them with spinosad, a bioinsecticide made from soil bacteria.

When grasshoppers hit your garden, nothing is safe. These insects chew their way through leaves, flowers and fruits without stopping, eating up to half their body weight per day. Kill grasshoppers when they're young anytime you can. Create a garden where bluebirds feel at home, because they'll help eat these pests, as will toads, snakes and shrews. Explore the world of grasshopper baits to discover bioinsecticides that kill these insects using various strains of fungi or bacteria. Don't just ignore grasshoppers, because if you have a severe problem one year, you will continue to have issues in the future.

The brown marmorated stink bug has been in the United States 20 years, and in that time it's spread throughout the Mid-Atlantic, Upper Midwest and along the West Coast. Stink bugs attack many home garden crops, including beans, corn, tomatoes peppers, apples and raspberries. Their feeding wounds fruits and veggies, resulting in corky spots that are inedible. Stink bugs spend winter inside, invading home voids and attics. With their stinky personalities, these bugs stir up drama indoors when they emerge from hiding in hordes, usually in winter. In the garden, knock stink bugs into soapy water to kill them. Indoors, the same method works, or you can try vacuuming up the stinkers (which might make your vac stink). Another indoor option is using a dry-mop cleaning tool (think Swiffer-type) that you cover with duct tape, sticky side out. That device gives you reach to grab stink bugs climbing curtains, walls and ceilings.

The caterpillar-like larvae devour the foliage on plants such as roses, gooseberries and Solomon's seal. Leaf rolling is usually the first sign of sawflies. Pick caterpillars off by hand or spray with bifenthrin or pyrethrum.

Seen in early summer, these white fluffy aphids coat shoots and the undersides of leaves. They suck sap and excrete honeydew that supports black sooty mold.

Mostly beneficial, earwigs are nocturnal and feed on dahlia, chrysanthemum and clematis flowers. Lure them into upturned flower pots filled with straw and release them elsewhere.

This pest is very destructive due to its voracious consumption of plants in the cabbage family.

Striped or spotted cucumber beetles like to eat melons, squash and cucumbers and can spread disease; the bacterial wilt of cucurbits.

Like scale, mealybugs are members of the Homoptera order (along with aphids). Mealybugs are found in cottony clusters in the nooks and crevices of plants and feed on plant juices and can spread plant diseases.

Tomato hornworms (Manduca quinquemaculata) feed on tomato plants.

Small holes in tomatoes are usually caused by slugs. The problem is, once slugs open a hole, the tomato weeps juice, and soon other critters join the party, like pill bugs, fruit flies and wasps. The wound in the fruit also invites early decay and mold. Slugs attack low-hanging fruit first, but they also slime their way up tomato vines and supports. Research slug treatments and adopt several strategies to deal with them. When tomato season is done, before frost, continue to use slug treatments to kill adult slugs before they lay eggs.

Snails like this European brown garden snail can wreak havoc on plants.

Flea beetles eat edibles like brassicas but can also attack ornamental plants in the garden.

The Colorado potato beetle, also known as the Colorado beetle, is a major pest of potato crops.

It's vital to destroy spent vegetable crops, especially those that hosted problem pests, like Mexican bean beetles. Don't toss these plants into a compost pile unless you know it heats enough to destroy pests and eggs. It's safer to dispose of infested plants and fallen leaves in bags you put at the curb for garbage pick up.

This large and very diverse family of insects prefers to feed on a large number of plants including herbaceous plants, fruit trees, vegetables and flowers.

RIFA colonies develop quickly; a new colony can grow by as many as 10,000 ants in a single year.

Cutworms are the larvae of several varieties of moths and are named because they tend to feed on the stems of young plants, cutting them down.

One of the most destructive asparagus pests, the asparagus beetle destroys garden and wild asparagus plants.

Germinating seeds, roots, bulbs and tubers are the wireworm's favorite meals.

The European corn borer has been a pest of crops in the Midwest since the Twenties and destroys a variety of crops and weeds beyond corn, including cotton, apples, soybeans, peppers and ragweed.

Ticks are human pests and carry a multitude of diseases, so are best kept out of the garden.

Squash bugs are among the most common and destructive pests affecting pumpkins and squash.

Carpenter ants damage wooden structures to nest within.

Found throughout North America, the corn earworm is a moth larva and a serious agricultural pest.

Leaf roller caterpillars often pupate inside canna leaves, damaging them as they begin to eat. Other leaf rollers attack fruits, ornamentals, and shrubs. If the infestation is light, squish the caterpillars inside the leaves, or unroll the leaves, remove the pests, and destroy them.

Grubs are the precursor to various types of beetles. One of the most destructive grubs is Japanese beetle, which lives in turf. These critters chew through grass roots, creating dead patches in your lawn. The best time to control grubs is in early fall, when they're young and feeding voraciously underground near the soil surface. Treat with parasitic nematodes, a microscopic worm that attacks grubs (Heterorhabditis bacteriophora is the best), or strap on a pair of lawn aerating sandals and spike the grubs to death. Concentrate your spiking steps on brown lawn areas and the green areas just outside the brown.