PHOTO: Courtesy of David R. Lance
USDA APHIS PPQ

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Brown marmorated stink bug
Halyomorpha halys

IDENTIFICATION — The brown marmorated stink bug, or BMSB, is about 1/2 in. long, shield-shaped and mottled brown. And the last two segments of the antennae have an alternating light and dark brown banding. Adult females lay clusters of 20 to 30 light green eggs on the undersides of leaves from June to August.

DAMAGE — This pest feeds on more than 70 species of ornamental plants, as well as soybeans and the fruit of many trees. And when cold weather arrives, masses of BMSB come knocking at your door. Though not harmful to people, this bug lives up to its name by emitting an unpleasant odor when disturbed.

CONTROL — It’s recently found its way to North America from Asia. First discovered in Allentown, Pennsylvania, in 2001, the extent of its range isn’t known. If you see one, contact your local extension agency or go to www.csrees.usda.gov/nea/pest/pdfs/stink_bug_pest_alert.pdf to learn more. To control BMSB use an insecticide containing bifenthrin or cyfluthrin, such as Baythroid^® or Aztec^®, and follow label directions.

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Black-legged or deer tick
Ixodes scapularis

IDENTIFICATION — Not all garden pests are found on plants. Some are actually on the gardener! Unfortunately, this pest is hard to spot. The black-legged tick (or deer tick), the main culprit in infecting humans with Lyme disease, is tiny. Brick-red adult females are about 3/25 in. long, and the black males are a little smaller. After feeding, females can be two to three times that size. During the immature nymph stage, they’re only about the size of the head of a pin and translucent with a gray tinge. This is the phase during which they’re most likely to attach to humans or pets and transmit disease.

Only 1 to 5 percent of black-legged ticks carry Lyme disease, most commonly in Canada and the northern United States.

CONTROL — The best control for black-legged ticks is to avoid them. They’re found in wooded areas or tall grass, so stay on paths and keep your lawn mowed. Keep pets in mowed areas, as they can bring ticks indoors or be infected with Lyme disease themselves. Mowing grass short raises the temperature and lowers humidity at ground level, which causes ticks to dehydrate and die.

Wearing long-sleeved, light-colored shirts and long pants helps keep ticks away and also makes it easier to see any that might have made it onto you. Tuck your pants into your socks to keep the little critters from crawling up your legs. Repellents with deet also keep ticks at bay.

After coming indoors from brushy areas, check for ticks, especially in your hair and around your waist and inner thighs. They need to be attached for a couple of hours to transmit disease, so removing them promptly is important. It’s best to use tweezers. Grasp the tick’s head and body and pull carefully.

For more information on Lyme disease, go to the American Lyme Disease Foundation Web site at www.aldf.com or the Centers for Disease Control and Prevention Web site at www.cdc.gov/ncidod/dvbid/lyme/.

PHOTO: © Mary Howell Williams

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Spotted cucumber beetle
Diabrotica undecimpunctata howardi

IDENTIFICATION — Adult beetles are 1/4 to 1/3-in. long and yellow to green with 11 black spots on their backs. The wormlike larvae are yellowish and start out about 1/8 in. long.

DAMAGE — Spotted cucumber beetle will attack most any type of flower, but also eats beans, tomatoes, cucumbers, melons and other edibles. Adults chew irregular holes in flowers, leaves and fruit from July to fall. The larvae (known as Southern corn rootworm) feed on corn roots in May, June and July, often transmitting bacterial wilt disease.

CONTROL — Beneficial nematodes can help. Buy them at local garden centers or mail-order sources, such as Gardens Alive. Mix the powder with water and water them into the soil late in the day in midsummer to control the larvae. For beetles, grow plants to attract natural predators (purple coneflower, hydrangea or Shasta daisy to attract soldier beetles, or angelica, thyme or yarrow to attract parasitic wasps). As a last resort, mix up and spray tops and undersides of leaves with horticultural oil or insecticidal soap (on overcast or cloudy days) as soon as you notice damage.

Eastern firefly
Photinus pyralis

IDENTIFICATION — Adult fireflies (also called lightning bugs) are actually winged beetles, not flies. Several species are found throughout the United States and Canada but the Eastern firefly is one of the most common. It’s found east of the Rocky Mountains in open, grassy areas.

With two red spots on their heads, adults have brown-black wings, edged with a light yellow stripe. During the day they seek out dark, damp places to rest, so you may not notice them. But it’s hard to miss these guys on hot summer evenings when they’re flashing their tail lights over and over. Summer is peak mating season for fireflies and the flashes of light are their mating calls. But the adults aren’t the only ones that light up — the segmented, six-legged larvae, and even the eggs, light up, too.

LIFE CYCLE — In early summer, the adults surface after a year underground. Around dusk, the males begin to fly and flash in search of a mate. Females respond with flashes, mate and deposit eggs singly or in groups in the soil around grass roots. Both adults die shortly after mating. Eggs hatch in about three weeks, and the larvae overwinter underground, emerging in the spring to begin the process again.

HOW TO ATTRACT — Both the firefly and its flightless larvae are good to have around. They eat aphids, slugs, earthworms, mites and pollen. Make your garden attractive to these bugs by giving them bark or mulch to hide under. Grow small trees and shrubs so flightless females have a spot to wait for their mates. Light pollution interferes with the mating process, making these insects harder to find in urban areas. So turn off the porch light to help them feel at home.

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Cabbage looper
Trichoplusia ni

IDENTIFICATION — Now’s the time of year to be on the lookout for a small 1 1/2-in. green caterpillar with white racing stripes and a voracious appetite each spring in North America. The cabbage looper can eat three times its body weight every day! And with two to seven generations each year, depending on the length of your growing season, that’s a lot of plant damage.

The moth has mottled brown wings with a single silver spot in the center and most often lays a single pale yellow to green egg on a leaf. But clusters of six or seven eggs aren’t uncommon. Cabbage looper’s favorite egg hosts are cruciferous vegetables, such as cabbage, turnips, kale and others, but it’s not picky. About three days after the egg is laid, a caterpillar emerges and starts eating.

DAMAGE — Yes, a cabbage looper loves to eat cabbage, but it also munches on broccoli, cauliflower, potatoes, lettuce, tomatoes and cucumbers. Ornamental plants, such as mums, carnations, snapdragons, geraniums and hollyhocks, are also on the menu. Avoiding the veins of the leaves, the cabbage looper eats irregular holes and can defoliate a plant in no time. This can stunt growth or even kill the plant. Be sure to check the centers of broccoli and other plants, as a cabbage looper will sometimes bore its way into the heads.

CONTROL — You can hand pick any caterpillars that you find. Or encourage predatory wasps and ground beetles to live in your garden by avoiding insecticides and leaving leaf debris or mulch around for hiding places. In turn, they’ll do you the favor of eating these hungry caterpillars. For serious problems, try a spray product containing neem. This organic pesticide stops the caterpillar from eating and disrupts its growth so much the insect dies.

from the wild side

Minute pirate bug
Orius tristicolor spp.

IDENTIFICATION — It may be tiny, but this 1/4-in.-long bug has a big appetite — for other bugs, that is. The minute pirate bug is most common in the western United States and Canada. It has an oval-shaped body with black and white wings like the one in the illustration.

Both the adult and nymph form of the minute pirate bug will eat just about any small insect. Thrips, mites and aphids are some of its favorites. That makes this feisty little bug a big asset in the garden. When prey is scarce, the minute pirate bug feeds on pollen and plant sap.

If you pick up a minute pirate bug, watch out! It will bite. Reactions range from nothing other than the initial discomfort to a small bump similar to a mosquito bite, without the itch. Think you’ve seen this bug in the Midwest? It’s probably the insidious flower bug (O. insidiosus), a close cousin.

LIFE CYCLE — In spring, minute pirate bugs lay eggs in plant stems or leaf tissues. Eggs hatch in three to five days, and the nymphs immediately start looking for small insects on which to feed. It takes about 20 days and five stages for a minute pirate bug to reach adulthood. Then after about a month it dies. Several generations of this bug can occur over the course of a growing season.

You probably already have minute pirate bugs or insidious flower bugs in your garden. But to keep them around and perhaps attract a few more, avoid spraying insecticides. Also, grow flat-topped flowers like daisies and yarrow, whose pollen is easy to get at. That way, these little garden helpers will have something to keep them going once they’ve whittled down the pest population in your garden.

PHOTO: Courtesy of Bradley Higbee,
Paramount Farming, Bugwood.org

from the wild side

Big-eyed bug
Geocoris spp.

IDENTIFICATION — These insects may not be pretty, but they’re good to have around. The appropriately named big-eyed bug is a predator other bugs steer clear of. There are 19 different species of big-eyed bug in North America, all with similar habits and life cycles. One of the most common, Geocoris punctipes, is shown above. Adults are about 3⁄16 in. long with transparent wings and a broad head as wide as the oval-shaped body. They have piercing-sucking mouthparts that they use to stab prey.

Big-eyed bugs usually eat whiteflies, aphids, mites, small caterpillars and even insect eggs. A single nymph can eat 150 tobacco budworm eggs while in this stage and an adult, up to 80 mites per day! They’ll occasionally feed on plants when prey is scarce, but damage is minimal.

LIFE CYCLE — Big-eyed bugs only live about 30 days. They emerge in spring to feed and lay eggs. These eggs hatch in about a week into tiny juveniles that look just like the mature bugs. What makes this insect so helpful is that males, females and all stages of juveniles eat insects — mostly those you don’t want around. Late-season adults spend the winter in leaf litter, turf thatch, under loose bark or any place they can find. Insects like big-eyed bugs that overwinter as adults have a chemical in their system to prevent ice from forming, almost like anti-freeze. Once the body temperature reaches 55 degrees F in spring, they start waking up.

Big-eyed bugs are so abundant you don’t have to do anything to attract them to the garden — they’re probably already there. But to encourage more of these hungry predators, avoid spraying insecticides.

from the wild side

Fiery searcher
Calosoma scrutator

IDENTIFICATION — Quietly going about the business of hunting insects, especially caterpillars, the fiery searcher is a helpful predator to have in the garden. The insect is colorful, with brilliant green ridged wing covers ringed in red. Its legs, abdomen, head and pronatum (the area behind the head) are shiny blue-black. Even though the fiery searcher has wings, it rarely uses them. It’s more likely to run for cover on its long legs than fly if it sees you coming near.

You’ll notice beetles emerging from their winter hiding places in spring to feed and mate. Eggs are laid singly in the soil and hatch into long, slender larvae with short front legs. It takes about a year for the beetles to mature. Juvenile beetles inhabit the soil and feed on a variety of insects, including caterpillars. Long-lived for insects, fiery searchers can reach the ripe old age of three or even four years.

Be careful if you handle these beautiful beetles. When startled, they release a foul odor as protection against predators, such as raccoons, frogs, birds, squirrels and other animals.

FAVORITE CONDITIONS — Found throughout North America, these ground beetles hide in leaf litter, under rocks or in decaying logs during the day and emerge at night to find a meal. One of the larger beetles, fiery searchers grow 1 to 1 1/2 in. long and have large mandibles for grabbing prey. They’re especially fond of tent caterpillars and gypsy moth larvae and will even climb trees to find a midnight snack.

HOW TO ATTRACT — You can’t buy these helpful creatures, but you can encourage larger numbers by providing hiding places, such as stepping stones, a compost pile or a rotten log. Also, avoid spraying insecticides whenever possible, since the chemicals will kill these beneficial insects along with the pests.

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Four-lined plant bug
Poecilocapsus lineatus

IDENTIFICATION — The four-lined plant bug is one of the most common pests in the garden. It likes to feed on more than 250 species of ornamental, woody and edible plants. In urban areas the four-lined plant bug is usually found on perennials and shrubs.

Damage from this pest starts in late spring when plant foliage has emerged and eggs hatch. Nymphs look like tiny adults but are bright red to orange with black wing pads. Over a period of about six weeks and several molts, the four-lined plant bug gradually changes color. Adults are yellow to chartreuse with, you guessed it, four black lines running down the wing covers on their backs. Since mature bugs have wings, they move from plant to plant, feeding for about a month until they mate. After mating, the female cuts a small slit in a plant stem to make a winter home for her cluster of eggs. By midsummer most of the adults have died. There’s just one generation of four-lined plant bugs each year.

DAMAGE — You’ll know four-lined plant bugs are around if you see tiny round sunken spots that are brown to translucent on the foliage of your plants. With heavy damage, the leaves might be distorted or curled.

Damage is often mistaken for leaf spot disease. But foliar disease spots from fungi or bacteria are irregular, and the marks left by the four-lined plant bugs are almost uniform in shape and size.

CONTROL — What can you do to get rid of this hungry insect? Start checking your garden in spring for damage. Since the nymphs can’t fly, their damage tends to be clustered in one area. And it’s easier to get rid of them while they’re less mobile. But whether you have nymphs or adults, the most environmentally friendly way to remove these unwelcome pests is with a few sprays of insecticidal soap.

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Cyclamen mite
Phytonemus pallidus

IDENTIFICATION — These minute, semitransparent mites are too small for the naked eye to see. They hide in young, tender stem ends, leaves and flower buds of cyclamens (Cyclamen spp.) and many other indoor and outdoor plants. But their damage is obvious. Like all sucking bugs, these spider relatives cause wrinkled, curled growth and stunted flowers and foliage. Their damage first appears as light, speckled areas, which later spread over the entire leaf surface. Affected foliage turns yellow and even­tually dies and drops off.

CONTROL — Cyclamen mites crawl from plant to plant across “bridges” where leaves touch each other or they hitch a ride on clothing or hands. Examine plants you bring into the garden or the house for signs of the pest, and wash hands and clothing after working with infested plants.

If you catch them early, you can remove cyclamen mites from plants with a high-pressure stream of water. Spray the entire plant, especially the undersides of the leaves, with a jet from a hose. Or, use an insecticidal soap, such as Safer^®, on all the leaf surfaces. Spray until the soap drips off. Just discard heavily infested plants in the trash.

from the wild side

Spined assassin bug
Sinea diadema

IDENTIFICATION — Spined assassin bug may have a sinister-sounding name but it’s actually one of the good guys. There are more than 100 species of assassin bug. Although some species are pests, this is one of the most common beneficials in the family. It’s found in central and southern North America and Mexico. Adults are 1/2 to 3/4 in. long, and brown with long legs, a broad flat abdomen and a narrow head with large eyes.

The segmented beak is used to spear and inject venom into prey. When not in use, the beak folds away under the bug’s body. As you might guess, the spined assassin bug does have spines. You’ll see them on its head, thorax and front legs. This hungry predator eats a wide variety of pests, including aphids, caterpillars, leafhoppers and larvae of all kinds. These bugs are generally harmless to humans but if handled roughly, they can inflict a painful bite.

LIFE CYCLE — Eggs of spined assassin bug that were laid in fall hatch as temperatures warm in spring. Nymphs, about 1/4 in. long, look like miniature adults and start looking for something to eat right away. After several molts, the nymphs mature and mate, then females begin laying eggs. The first generation lives about two months and then dies. The second generation follows the same cycle, living until late fall. Eggs laid by these females will hatch the following spring.

You may already have spined assassin bugs in your yard since they are fairly common. Give these hungry predators a variety of blooming plants to hide in and they’ll help you out by hunting for insect prey. To be sure they stick around, avoid using pesticides.

Click to see a larger image.

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Rose slug sawfly
Endelomyia aethiops

IDENTIFICATION — Smooth, translucent pale-green larvae could attack the leaves of your roses next May and June.

DAMAGE — Feeding on the surface of the foliage between the veins, larvae create a window-pane look. Leaves turn brown and curl. Large infestations may stunt the plant’s growth.

CONTROL — Prune out or handpick small populations. On cloudy days (so you don’t burn the leaves) in early summer, spray all plant surfaces with Safer^® insecticidal soap or horticultural oil to smother younger larvae. These controls don’t work as well on older larvae, but most of the damage has already been done by then.

If there are so many larvae that the plants stop growing and blooming, dust the affected plants with an insecticide containing carbaryl, such as Sevin^®. Or dilute and spray spinosad on all leaf surfaces in early summer. And all season, pick up debris and leaves from around plants to remove any larvae that may be hiding there.

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Pillbugs and sowbugs

IDENTIFICATION — Here are two bugs that look almost identical — pillbugs and sowbugs. The only difference seems to be that pillbugs roll into a ball when they’re frightened. Both go by many different names, such as roly-poly and wood lice. And they’re really not bugs at all — they’re crustaceans — they’re more closely related to crabs and lobsters. Adults can grow to 3/8 in. long.

DAMAGE — These bugs don’t really harm plants unless there are so many that the creatures need the food. Then they’ll feed on fine roots and stems of tender seedlings. Usually they’re scavengers, feeding on decaying plant material and hiding in dark, damp areas.

CONTROL — There’s no urgent need to control either one. But if you feel overrun, take away the critters’ hiding places. Remove dead plant material to the compost pile, get rid of boards and lift pots off the ground. These are some of their favorite spots.

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Flea beetle
Melittia cucurbitae

IDENTIFICATION — Young leaves of vegetables and flowers riddled with “shot” holes are a sign that flea beetles may be attacking your garden.

These small, black insects aren’t really fleas, but they jump like them. Although there are several species, damage and identification are the same.

DAMAGE — Adults chew round holes in the leaves, especially those of young plants, and on tender new growth. Foliage pierced with holes dries out quickly and dies. Flea beetle larvae sometimes feed on plant roots.

CONTROL — Adult flea beetles live over the winter in the soil and in debris. By cleaning up the garden in the fall, you’ll eliminate some of their hiding places.

Because they can produce a few generations each year, it’s important to get control of a population first thing in the spring. Protect young plants with spun-fabric row covers. Or, once you begin to notice damage, spray with neem oil or insecticidal soap every week or so.

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Squash vine borer
Melittia cucurbitae

IDENTIFICATION — There’s nothing worse than having your squash die on the vine because of squash vine borers. Adult moths are about 5?8 in. long with translucent wings. They have an orange and black striped body with fringed hind legs. Females emerge in spring to lay pinhead-sized eggs on the lower 3 to 4 ft. of squash vines.

Once the eggs hatch, the larvae bore into the stem and start eating. They grow up to an inch long with a white body and brown head. Larvae live and eat in the vine for four to six weeks, then move from the plant into the soil, where they spend the winter in a cocoon.

DAMAGE — Squash, zucchini, pumpkins and gourds are all susceptible to attack by these pests. Their favorite variety is Hubbard squash. Butternut squash, cucumbers and melons are less palatable but are sometimes affected. If the vines in your garden suddenly wilt, take a look at the base of the plant. Look for small holes in the vine, along with an accumulation of sawdustlike material. That’s frass, the debris larvae produce as they eat their way through the vine. As they eat, the larvae cut off water and nutrients, which kills the plant.

CONTROL — Because squash vine borer larvae are inside the vine, it’s difficult to get rid of them. But if you keep at it, you can minimize damage. In late spring, spray the vines weekly with an insecticidal soap to smother the eggs. Or spray the vine with Bt before the eggs hatch. This natural insecticide is safe to use on vegetables but needs to be eaten by the pest to be effective. In fall, destroy the vines as soon as possible after harvest to get rid of any remaining larvae. If you can till the soil to expose any cocoons to cold and predators, that will help, too.

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Emerald ash borer
Agrilus planipennis Fairmaire

IDENTIFICATION — If you have an ash tree (Fraxinus spp.), keep an eye out for emerald ash borer. Native to Asia, this pest is a serious problem in Michigan, Indiana, Ohio and Ontario. Several surrounding states have infestations to a lesser degree.

Emerald ash borers (EAB) are slender with metallic green wing covers. But you don’t have to see the insects to know that they’re there. Adults chew small, 1/8-in.-diameter D-shaped exit holes in the tree in spring. Soon after they emerge, females start laying eggs in the crevices of ash tree bark. Larvae burrow back into the bark to overwinter, pupating into adulthood in early spring.

DAMAGE — Adults feed on leaves and don’t do a lot of damage. It’s the larvae, which feed under the bark, that cause problems. They disrupt the flow of water and nutrients, which eventually girdles and kills the tree. The tree can die within two years of initial symptoms. White, green and black ash trees are equally tasty to EABs. Dieback usually starts in the top third of the canopy and works downward.

CONTROL — New treatment methods provide hope that this pest can be beaten. The new pesticide Tree-age^® did very well in 2007, its first year of use. It’s applied every other year by trunk injection and can only be purchased and applied by certified arborists or landscapers. In Canada, a similar treatment, TreeAzin^®, is working, too. Predator wasps native to China have been released in Indiana, where results are still pending.

You can help prevent movement of EAB by not transporting firewood or logs from quarantined states to others. For more information check out www.emeraldashborer.info. If you suspect your tree has an infestation, contact your local extension agency to report it.

Click on the photo to see the damage

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Three-lined potato beetle
Lema trilinea

IDENTIFICATION — True to their name, these beetles have yellow bodies with three black stripes running down their length. Their heads are red-orange with thick black antennae.

DAMAGE — Larvae and adults chew ragged holes in the leaves of datura, nicotiana, tomato, potato and some other vegetables in midspring to midsummer.

CONTROL — Handpick adults in early spring if you can see them. As soon as you see damage in spring, mix up and spray tops and bottoms of leaves with Bacillus thuringiensis (Bt), a beneficial bacteria you can buy in granular or liquid form. Repeat spraying every week or so until midsummer. Dust plants with Sevin^® in early spring to kill the beetles. To avoid scorching plant leaves, don’t apply Sevin in liquid form during the hottest part of the day or if temperatures are above 85 degrees.

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Tobacco budworm
Heliothis virescens

IDENTIFICATION — Tobacco budworm larvae are generally yellow to yellow-green with a brown head, but body color can sometimes be pink, red or maroon, as well.

DAMAGE — Most larvae appear in August or early September and attack petunia, geranium, nicotiana, ageratum, mum, snapdragon, strawflower, rose and other flowers. They tunnel into or eat entire flower buds and petals and sometimes leaf buds, too.

CONTROL — Handpick from plants around dusk when caterpillars are least active. Buy beneficial insects, such as stink bugs, green lacewing larvae and lady beetles from garden centers or mail-order sources, such as Gardens Alive. Release them on calm days in late spring, in early morning or early evening. Mix up pyrethroid insecticides and spray plants until leaves are dripping. These chemicals attack all stages of the insect, as well as the eggs, so you may only need to make a couple of applications.

asian lady beetles

Harmonia axyridis

Multicolored Asian lady beetles, or ladybugs, are beneficial, but you might not think so when they swarm your back porch or come indoors for a visit. Like the many other species of lady beetles, they feed on aphids and soft-bodied insect pests that attack flowers and vegetables. The best way to identify a multicolored Asian lady beetle from other species is by the distinctive “M” marking on the back just above the colorful wings. These lady beetles vary in color, from green to orange. And the number of spots on their backs varies.

Asian lady beetles don’t feed on wood, fabrics or human food. Nor do they sting, carry diseases or bite, although you may get a startling pinch from one. This pinch does not break the skin and is usually only a problem when your skin is moist on warm days. When you handle Asian lady beetles or step on them, they release a yellowish fluid that’s harmless but smells awful. And it can leave a stain. Always sweep up and dispose of dead beetles. Particles from the dried and crushed bodies can affect people with respiratory problems.

PHOTO: © Mary Jane Hayes

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Eastern tent caterpillar

IDENTIFICATION — There are several kinds of caterpillars that spin webs in trees, but you’ll see Eastern tent caterpillars and their webs in late spring or early summer. They’re black, with irregular blue and white markings and a solid white stripe down the back. Adult moths are about 1 in. long and red-brown with two white stripes on the front wings.

DAMAGE — Usually, the worst thing about these caterpillars is that their webs look messy, but the pests can defoliate and stress small trees. You’ll see webs in the forks of twigs or branches of trees east of the Rocky Mountains. Webs usually don’t enclose leaves, as the caterpillars leave the webs to feed. They generally feed in the morning or evening, when it’s cool, but may also feed during the day. If it’s raining or hot, they often retreat to the web.

CONTROL — You can pull down the webs, pests and all, and destroy them. Check the web first to be sure the caterpillars are “at home.” Wear gloves, because the hairs on the caterpillars can irritate some people’s skin. A strong jet of water can help knock down webs that are too high to reach.

Bt (Bacillus thuringiensis) is a common control, but it has to penetrate the webs to be effective. And you may need a professional to spray a large tree.