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GARDEN TIPS – Written by Marianne Ophardt
WSU Extension Faculty
for the Tri-City Herald, Kennewick, WA Published September 4, 2016

It was never a matter of “if” the Japanese beetle would reach the Pacific Northwest, it was a matter of “when” it would get here. That could be now. Numerous adult beetles have been trapped and found eating on roses and other plants in Portland, according to the Oregon Department of Agriculture (ODA). ODA says that this suggests “a breeding population of the non-native insect has been established.”

Uh oh! This is terrible news for gardeners and growers. A University of Kentucky publication says that “the Japanese beetle is probably the most devastating pest of urban landscape plants in the eastern United States.”

I am willing to bet that if you migrated to this area from the eastern part of the US, you already know too well why a Japanese beetle infestation is scary. As a pest, this rather pretty beetle packs a double whammy. Its grubs feed on grass roots and can be very damaging to lawns. The extremely voracious adults are omnivorous, feeding on a wide variety of plant hosts including roses, ornamentals, trees, shrubs, fruit, and vegetables, often devouring the upper sides of plant foliage, leaving only the skeleton of veins and midribs behind.

The Japanese beetle is one of the scarab beetles and could be considered attractive if you like beetles. The adult beetle is almost ½ inch in length with metallic copper wing covers and clubbed antennae. The head and thorax in front of the abdomen are metallic green. Along the sides of the abdomen are hairy patches that look like white spots.

Like so many damaging insect pests, the Japanese beetle is an alien, coming here from Japan. It was first identified in the eastern US in 1916 and it became established in all the states east of the Mississippi, except for Florida, by 1998.

Besides its rapacious appetite, this beetle’s propensity for aggregating on plants can lead to rapid and complete defoliation of a plant. Japanese beetle-damaged plants emit volatile chemicals that bring more beetles to the party. In addition, the unmated females emit a pheromone to attract even more hungry beetles. Once done with one plant, they move onto another.

Thankfully, there is only one generation of Japanese beetles a year, but with each adult female laying from 40 to 60 eggs, populations can build quickly. Control with pesticide applications is aimed at both the adults on plants and their grubs in the soil. You may see Japanese beetle traps advertised for their control, but university research indicates that the traps are effective in monitoring for the beetle’s presence, but not for control. In fact, the traps can result in more of the beetles finding your yard and causing damage.

Over the years ODA has been working to contain and eradicate any Japanese beetle infestations that they have detected. They believe that the origin of these infestations are air cargo carriers coming in through the Portland International Airport. ODA estimates that the current infestation has been present for more than a year without detection. Right now they are trying to pinpoint where the breeding population is located so they can treat the infestation next year.

For us in Washington, it is good to know that the Washington State Department of Agriculture (WSDA) has been on the watch for the Japanese beetle and has been conducting trapping each year since the mid-1980s to make sure they have not become established anywhere in the state. So far, WSDA has not had to conduct eradication measures on a breeding population yet. I hope it stays that way.


written by
Marianne C. Ophardt
WSU Extension Faculty
for the Tri-City Herald, Kennewick, WA
August 22, 2014


‘True bugs’ are a group or ‘order’ of insects called Hemiptera, They have a number of characteristics in common, One common trait is their piercing and sucking mouthparts that enable them to suck sap from plants or body fluids from insects or animals. They have two sets of wings, Their front wings are leathery at the base and membranous at the end. Their hind wings are membranous and shorter than the front ones. When at rest, the wings typically create a triangular shield-shape pattern on their backs.

Some bugs, like squash bugs and bed bugs, are pestiferous, Others, like assassin bugs and damsel bugs, are beneficial, Bugs can be very tiny, only a couple of millimeters in length, or they can be relatively large, measuring up to two inches in length.

Bug bodies come in various shapes, but are often flattened on top, A number of bugs have scent glands that produce stinky smelling chemicals when they are disturbed.

As a group, bugs have what is called ‘incomplete’ or simple metamorphosis, going from eggs, to five stages of flightless nymphs, to adults, They have no larval or pupal stages. The nymphs resemble the adults, but are smaller and lack working wings.

Is it a good bug or a bad bug? The tiny ‘minute pirate bug’ often goes unnoticed because it is so small, only 1/12 to 1/5 of an inch in length, Their little bodies are black with white markings on the front wings, Minute pirate bug adults and their nymphs are hungry little guys that suck out the body fluids of 30 to 40 aphids or mites each day, If this preferred food is not available, minute pirate bugs can find nourishment from plant nectar, pollen, and plant juices,

Local veggie gardeners know squash bugs are ‘bad bugs.’ Squash bug adults have dark brown to gray, 3/4 inch elongated flattened bodies, Young nymphs are light gray-green with black legs,

Squash bug adults and nymphs are primarily a pest of winter squash, pumpkins, and summer squash, but occasionally attack melons and cucumbers, They damage plants by sucking out the sap and leaving yellowish specks that later turn brown, The specks are not a big problem, but heavy feeding by squash bugs can cause entire leaves and vines to wilt, turn black and die. Their feeding can also cause scars and sunken areas on squash fruit.

Control of squash bugs is not easy, Starting in June, gardeners should check weekly for clusters of copper colored eggs on the lower surfaces of the leaves and crush any clusters they find with their fingers, Cleaning up debris in the garden and avoiding the use of mulches helps eliminate squash bug hiding places. It is also advisable to rotate garden crops so that squash is not planted in the same area every year.

Pesticides are available for control of squash bugs but they must be applied very carefully to protect any bees visiting squash flowers, The bees are needed for pollination, Apply labeled products only in the evening at dusk and only apply them at the base of plants and vines where the squash bugs tend to concentrate, When using pesticides for control, make your first application when egg clusters are discovered and then a second application a week or so later, This timing will help keep population numbers under control,

There are many more true bugs gardeners encounter, some good and some bad, What’s bugging you?

Published: 8/22/2014 11:34 AM


written by
Marianne C. Ophardt
WSU Extension Faculty
for the Tri-City Herald, Kennewick, WA
Published 8/1/2013

I must admit that I’m a bit tired of having to water my large flower pots and container vegetables almost every night. After a month of very hot weather, it has becomes a tedious chore. This is the time of year when gardeners like me would like to sit back and enjoy our gardens, but there is always something to do. Here are some of those gardening ‘to-dos.’

One task I put off during hot weather was deadheading my perennial flowers. I plan to get out there soon and get rid of the many faded flowers. It should make the garden look more tidy and a bit less ragged.

I can’t reach the back of my beds easily with flower shears, so last year I bought a three foot long-reach pruner. It allows me to extend my reach to the back of the bed and cut off the spent flowers there. The ‘cut and hold’ feature of the pruner lets me snip off the stem and hold onto it for retrieval.

Individual cuts for deadheading perennials with lots of stems, such as lavender, is too tiresome of a task for hand shears or a long-reach pruner. To take care of the multitude of flowers stems on perennials like lavender and salvia, I deadhead using a small rechargeable electric hedge trimmer.

Isn’t it amazing how fast some weeds grow in hot weather? I’ve been pretty good about keeping up with weeding even during the hot weather, although some weeds were sneaky and hid under other garden plants. Whatever annual weeds have escaped your past scrutiny, they should now be pulled to prevent them from dropping their seed that will become next year’s weeds. Do not put annual weeds that have already flowered and gone to seed in the compost pile.

Speaking of weeds, do you mulch your perennials and landscape beds? I use shredded bark mulch. A three to four inch layer of an organic mulch like bark provides good weed control and helps conserve soil moisture. Late summer is a good time to think about renewing your mulch if it has decayed to a depth of less than three inches.

Last year at this time of year I was so proud of myself for buying plastic labels and labeling all of my perennials. I could never remember what perennial was coming up where in the garden. This spring I went out to my garden and found that the permanent pen that I had used wasn’t permanent on the labels. I was disheartened to find that the labels were all blank.

Now I have to label my plants all over again. This time I’m going to try a ‘Garden Marker’ pen that is designed for marking plant labels with ink that is UV resistant to reduce fading. There are more expensive labels that I could buy where you engrave the plant names on an aluminum or I could print out names from a label maker. I’ll let you know how it goes. Tip: An even less expensive way to label your plants is to cut off sections of old plastic mini-blinds to use as labels.

Not only is late summer a good time to label your plants, it’s also a good time to assess your garden and see if there are any plants you want to replace or perhaps some empty spaces you need to fill. I have some empty spots thanks to a pesky gopher that killed several plants. The gopher is gone and now I get the chance to try something different.

Even if your garden looks a little worse for wear after our hot spell, the gardening season isn’t over yet. I may be tired of watering, but I am enjoying all the delights of my garden, the flowers, the finches, the dragon flies, and the honeybees. How about you?

Published: 8/1/2013 11:34 AM


written by
Marianne C. Ophardt
WSU Extension Faculty
for the Tri-City Herald, Kennewick, WA
Published 8/8/2013

Every night when I water my container garden flowers I am often ‘stung’ at least once by a minute pirate bug. They don’t actually sting, but they hurt a little because they are inserting their beaks into my skin. They don’t inject any venom or saliva. It doesn’t seem possible that these tiny black bugs could cause any pain, but it is uncomfortable when they probe you. They are easily brushed away and no itching or stinging usually follows the bite. It is a bit of a nuisance though.

Minute pirate bugs are very small, only about 1/8 to 1/5 of an inch long with an oval shape and flattened back. Their bodies are black with whitish markings. What are these little guys doing in my flowers? While annoying to me, minute pirate bugs are considered beneficial insects because they feed on other insects. They feed by piercing the bodies of small insects and sucking out their body fluids. Their diet includes thrips, psyllids, aphids, chinch bugs, spring tails, plant bugs, whiteflies, spider mites, insect eggs and little caterpillars. They also feed on the eggs and young larvae of corn earworm.

Given their diminutive size you might not think their predatory behavior very useful in the garden, but they are used in some greenhouses to help control thrips. I would guess they are eating flower thrips that are feeding on my container garden blossoms. So even though these little guys occasionally annoy me with their probing, I see no need to get rid of them.

A less common insect found its way into my office after a WSU Master Gardener discovered it on the leaves of her poplar tree. It is the bumble flower beetle. I first encountered this beetle last year. It’s a scarab beetle that is a little more than a half inch long and not quite as wide. It’s not distinctive because of its coloring which is yellowish brown to reddish brown in color with rows of small black spots on its back. A closer look reveals a very hairy head, thorax, underside, and legs. You might think that the bumble flower beetle (or BFB for short) name comes from this hairiness, but it is because of the loud buzzing noise, similar to that of a bumble bee, it makes when flying.

The BFB is generally considered a beneficial insect because its larvae (white grubs) feed on rotting organic matter, such as manure and rotten hay or vegetable matter, aiding in the decomposition process. The adults are attracted to sweet and fermenting plant juices. This includes the nectar of flowers like sunflowers, daylilies, and thistles; sap coming from tree wounds; and ripe or damaged fruit like apples, pears, peaches, and grapes. They are also attracted to the fermenting sap that oozes out of the trunk of willow or poplar trees infected with slime flux disease.

Generally, the BFB is not considered a pest. When found on damaged fruit, it is usually there because of the fermenting plant juices and only occasionally causes damage to ripe sweet corn and fruit. Finding a bumble flower beetle in your yard or garden shouldn’t cause alarm, but you may not want to handle the live beetles because they give off a defensive chemical that smells a bit like chlorine.

Have you discovered any interesting insects in your garden?

Published: 8/8/2013 11:12 AM


written by
Marianne C. Ophardt
WSU Extension Faculty
for the Tri-City Herald, Kennewick, WA
Published 6/27/2013

I am not immune to the unpleasing and bothersome damage caused by garden pests. Here’s what’s bugging me in my garden:

The tobacco budworm is an insidious creature that eats holes in my petunias even before they open, leaving them holey and tattered. The tobacco budworm (Heliothis virescens) is the caterpillar of a medium sized (1.5 inches across) greenish brown moth. At night, adult female moths lay eggs on the buds of garden flowers. These eggs hatch into larvae or caterpillars that nibble their way into flower buds and flower centers. When feeding is severe, the flowers may not open at all.

The caterpillar can be elusive, varying in color from light green to red or brown, partly because of the color of the flowers that it is eating. It is hard to find budworms during the day because they are hiding at the base of the plants. There is a better chance of encountering them at dusk, when they come out to eat.

It was once thought that the tobacco budworm would not overwinter here, but mild winters and a lack of deep frost have allowed it to become established in some area gardens, like mine. Control is difficult because it is resistant to most garden insecticides.

The newer synthetic pyrethrin insecticide sprays are the materials most likely to be effective.

If you would rather use an organic insecticide, Bacillus thuringiensis, also known as ‘Bt,’ is an alternative. This a bacteria that disrupts the guts of moths and caterpillars, but to be effective, it must be applied where the caterpillars will ingest it.

The budworm isn’t the only culprit attacking my flowers. Another caterpillar is infesting the daisies and its relatives: the sunflower moth (Homoeosoma electellum). The larvae, or caterpillars, of this moth attack sunflowers and other members of the aster family.

An examination of infested flowers reveals mats of webbing in the center. When you tear apart the center, there is more webbing and caterpillar frass. The adult female sunflower moth is nocturnal and lays its eggs at the base of flowers just starting to bloom, laying about 30 eggs a day.

The eggs hatch in two to three days, and the larvae begin eating pollen and flower parts, and then eat their way into the center and base of the flower. Young larvae are yellow but later change to brown or purple with whitish longitudinal stripes. After about two weeks, they change into a moth.

Control of the sunflower moth is the same as with the tobacco budworm: sprays of Bt or synthetic pyrethrins at dusk. These should applied two more times at five days intervals.

Read more here:

Published: 6/27/2013 3:09 PM


written by
Marianne C. Ophardt
WSU Extension Faculty
for the Tri-City Herald, Kennewick, WA

‘Midnight marauders’ were the topic of one of my columns a while back. Before I launched an updated version this week, I checked to see when I wrote the previous one. It was in May of 1989. It’s definitely time to bring you up to date on the creatures that plunder our gardens under the cloak of darkness.

If no culprits can be found feeding on damaged plants during the day, the best way to determine what miscreants are at fault is to venture out after dark with a flashlight and catch them in the act. Here are the culprits you’re most likely to find.

SLUGS: Many gardeners new to the area don’t think we have slugs here, but area gardens do host these slimy mollusks that munch on plants at night. Sometimes in early morning you can see a glistening trail of slime that they’ve left behind on plants. Slugs will feed on both the tender leaves of young plants, as well as the tougher leaves of older plants. On older plants their damage is characterized as ragged chewing. On younger plants they devour large parts or entire young seedlings. According to WSU Hortsense, additional evidence of their presence includes ‘pretzel‑shaped’ fecal droppings.

EARWIGS: Most area residents are familiar with earwigs, those reddish brown fast-moving insects about three-quarter inch in length with a set of pincers at the end of their abdomen. During the day they like to hide in dark, moist tight spaces. I suspect they’ll be numerous in area gardens this year because they prosper when spring and early summer weather is wet.

These omnivores are considered beneficial because they feed on insect pests like aphids and mites, but they also feed on tender plant tissues, such as young seedlings and delicate flower petals. They can decimate seedlings, but on older leaves their feeding is characterized by small to large irregular holes and damage along leaf edges. On the surface of ripe soft fruit, including peaches and strawberries, they’ll leave shallow holes. Earwigs also feed on corn silks interfering with kernel formation.

CUTWORMS: Cutworms are the larvae or caterpillars of night flying moths and get their name because some cutworms eat around the base of young plant stems which results in ‘cutting’them off. Cutworms are not remarkable in appearance. They have hairless tan, gray or greenish bodies with various indistinct markings. Ranging from one quarter to one inch in length, they curl up when disturbed. They hide under plant litter, soil, and mulch during the day. Their main source of food is weeds, but they also feed on garden plants.

ROOT WEEVILS: Root weevils are another pesky nighttime insect. The adult weevils are black to brown snout-nosed beetles about one quarter to one half inch in length. Their damage is characterized by notching of leave edges, making them look like someone has cut along the leaf edge with pinking sheers. Root weevils attack over 100 plant species but seem particularly fond of lilac, euonymus, strawberries, peony, rose, rhododendron, and azalea. During the day they hide under plants in loose soil or plant debris.

If you go to bed as soon as the sun sets or you

re nervous about looking for nocturnal pests in your garden after dark, you can try trapping the offenders by placing damp, tightly rolled up newspapers near the plants under attack. Check the traps in the morning for slugs, earwigs or root weevils. Next week we’ll talk about what control approaches work best for these midnight marauders.

Published: 6/15/2012 2:54 PM


written by
Marianne C. Ophardt
WSU Extension Faculty
for the Tri-City Herald, Kennewick, WA

Last week we talked about ‘midnight marauders,’ garden pests that attack plants at night. This includes slugs, earwigs, and root weevils. Today let’s talk about how to manage them and limit their damage.

Many of these nocturnal pests hide in nearby weeds or under plant debris during the day, so the first step is to tidy up the garden. Get rid of hiding places in and near the garden, such as rocks, boards, clumps of dirts, and plant litter. Remove or mow tall grasses and rogue out weeds in or near the garden.

Welcome birds, spiders, ground beetles, garter snakes, and frogs to your garden. These natural predators can help keep these pests in check. Earwigs and slugs prefer damp conditions. By using drip irrigation in your garden and drying out the soil surface, both can both be discouraged.

If these simple measures fail to keep these pests in check, trapping is a non-chemical control approach to take before using pesticides as a last resort.

SLUGS: Traps are easily created with deep saucers, pie pans, or cans sunk in the ground so the edge of the container is level with the soil. Beer is added to attract slugs withing a few feet or so from the trap. The slugs crawl into the trap and and drown. Remove dead slugs daily and refresh with new beer every few days.

Slugs can also be trapped by placing boards or wet unrolled sections of newspaper down on the soil near damaged plants. Each morning lift them up and handpick any slugs hiding underneath.

EARWIGS: When earwigs have been a significant problem in your garden in past years, frequent shallow cultivation of the soil, especially early in the spring, will disrupt nests and destroy eggs.

Earwigs can be trapped in shallow tuna or cat food cans. Place the clean cans in the garden and fill them with about a half inch of vegetable oil. The earwigs climb in and drown. Make sure the level of the oil is at least one inch below the edge of the container. When full of earwigs, empty and renew the trap. Some gardeners say adding a few drops of molasses on top of the oil makes the traps more attractive to the earwigs.

Another earwig trap consists of loosely rolling up a moistened section of newspaper and securing it with rubber bands. The roll will trap more earwigs if baited with wheat germ or wheat bran before rolling. In the evening, place the moistened rolls out in the garden near damaged plants. In the morning, collect the rolls, seal them in a plastic bag and dispose of them in the garbage. Repeat this nightly for several weeks.

ROOT WEEVILS: A simple method for trapping root weevils is to place a sheet beneath each of the damaged plants in the evening. Then go out well after dark with a flashlight and shake the affected plants. The feeding weevils will drop to the sheet. Collect the weevils and drop them in some soapy water. Do this nightly until you are catching few to no weevils.

LAST RESORT: There are a number of pesticide products available for control of slugs, earwigs, and cutworms in the garden. If you’re using the product in a vegetable garden, make sure it’s recommended for use around food crops. Slug baits containing iron phosphate are effective and less toxic than other baits. Whichever products you select, be sure to read label directions. Note that baits can be attractive to pets. Follow all label precautions to avoid poisoning pets or bees.

Published: 6/22/2012 2:44 PM


written by
Marianne C. Ophardt
WSU Extension Faculty
for the Tri-City Herald, Kennewick, WA

A new worry in the garden… western flower thrips. We’ve talked before about these tiny little insects that damage rose buds with their feeding, but a variety of other garden flowers are also being attacked. Thrips have rasping mouth parts that they use to tear tender flower tissues and then slurp up the fluids that leak out. Their feeding causes streaks and blotches on flower petals. When severe, flowers may even fail to open.

While western flower thrips are commonly found on roses, they can also attack almost any type of flower and are known to attack over 200 species of plants in 62 different families. They favor white to yellow flowers and their preferred hosts in the garden are roses, mums, geraniums, impatiens, fuchsias, marigolds, pansies, petunias, and carnations.

Thrips are minute, just one-fifth of an inch in length, with slender bodies, making it difficult to detect their presence. The easiest way to check is to tap flowers over a white piece of paper and look for their yellow to tan fast moving little bodies. I had been blaming the weather for the failure of my geranium flowers to fully open until I used this method to check for thrips. Aha! Thrips were the culprits. They’re also causing streaks on the petals of my miniature daylilies. I know they must also be feeding in other flowers, but they aren’t causing the severe damage seen on my geraniums, roses, and daylilies.

Before we discuss control, let me point out some things you should know about these flower feeders:

1. Thrips populations can build up quickly. Female thrips don’t need a male to reproduce and each is capable of laying 300 eggs in plant tissues. The eggs which hatch in a few days to a few weeks (in cooler weather) mature in two weeks, allowing for multiple generations during the growing season.

2. Thrips are active flyers and are capable of moving from plant to plant.

3. Because of the damage they cause to numerous agricultural food and fiber crops and because they have multiple generations during the season, thrips have built up a resistance to many insecticides. Scientists have also found that the outer covering on thrips’ bodies blocks the penetration of insecticides. Add to this the fact that thrips are often feeding within buds or at the base of petals where they’re protected from insecticide applications.

Obviously controlling flower thrips isn’t going to be easy. It’s made more complex by the fact that most pesticides that might be effective in controlling thrips are also likely to be toxic to bees visiting the flowers. An integrated approach to managing thrips is advised. This consists of:

-Pruning out infested flowers and buds and removing them from the garden.

-Getting rid of weeds in and around the garden.

-Avoiding lush, vigorous plant growth that results from excessive fertilization or heavy pruning.

-Using blue, white, or yellow sticky traps to scout and trap thrips.

-Wetting plant surfaces with sprinkler irrigation to deter thrips.

-Encouraging beneficial insects, such as lady beetles and lacewings which feed on thrips.

-Using the least toxic insecticides recommended for thrips control and following label directions.

Insecticidal soaps and summer oils can provide a quick knockdown of some of the thrips, but repeat applications will be needed. Apply insecticide materials directly to buds and flowers. Because theses materials may damage flowers, you should test several flowers first. Only treat badly infested plants where the thrips damage is too severe to be tolerated.

Published: 7/6/2012 2:47 PM


written by
Marianne C. Ophardt
WSU Extension Faculty
for the Tri-City Herald, Kennewick, WA

The Difference Between Yellowjackets and Paper Wasps

Are yellowjacket and wasps the same pest? No, they’re different and we have both in our area. Paper wasps are a real nuisance in my yard. They’re social wasps (living in groups) and build relatively small open-celled nests (not enclosed with a papery covering.) Our native paper wasps are distinctly different from yellowjackets. They have reddish brown slender bodies with yellowish markings and long dangling legs.

However, our area of Washington has been invaded by the European paper wasp. It has a larger shiny black and yellow body that looks much like the common yellowjackets of the region. Unlike yellowjackets, these invasive paper wasps don’t scavenge for food and are considered beneficial because they eat live insects. They’re often a problem because they build their nests almost anywhere in the yard and will sting if their home is threatened.

The common area yellowjackets build large enclosed papery nests in the ground. The entrance to their nests is small and often unnoticed. During the summer the yellowjackets are helpful by eating live insects. They also forage for other sources of protein, such as dead animals, garbage, and ripe fruit.

Once they secure their dinner, they chew it up and return to their nest to feed it to developing larvae. The larvae in turn produce a nutritious liquid for the adult workers to eat. Yummy! In the fall, the yellowjackets’ insect prey start to disappear plus fewer yellowjacket larvae are available to produce their dinner. Without enough food they turn aggressive when seeking out both protein and sugar based foods. That’s when they become a hazard at outdoor feasts.

How to Trap Yellowjackets

I’ve tried using a bright yellow manufactured trap, as well as a homemade trap baited with sweet syrup and fruit juice, but both didn’t trap any yellowjackets. I have lots of yellowjackets around my yard and I want to get them under control before my big barbecue next week. What am I doing wrong?

The problem may be that you have a problem with paper wasps, not yellowjackets. The good news is that paper wasps don’t forage for protein and sweets at picnics. If they’re causing you a problem near a picnic table, they’re probably defending a nearby nest. Try to locate their open-celled nests and treat with an appropriate aerosol insecticide product labeled for wasp control. To avoid getting stung, follow label directions and apply the spray during the evening when it’s almost dark.

If yellowjackets are a problem, lure traps will work for some types of yellowjackets, but their trapping potential can be enhanced by using meat, such as chicken, as an attractant. The meat should be replaced frequently, along with removing the dead yellowjackets. Place baited traps around the periphery of your yard. If you’re trying to protect a picnic spot in a larger area, place the traps about 200 feet away, spacing them every 150 feet apart.

I have tried the WHY traps you recommended for yellowjacket and paper wasp trapping but they don’t seem to work. How come?

The WHY traps work well for the common yellowjackets and native paper wasps in our region, but their attractant doesn’t appear to be effective for the European paper wasp which now outnumbers the native one. Dr. Peter Landolt, the USDA scientist who developed the attractant for the WHY trap, is trying to develop an attractant that will work for the European paper wasp.

Published: 8/24/2012 2:05 PM


written by
Marianne C. Ophardt
WSU Extension Faculty
for the Tri-City Herald, Kennewick, WA

The brown marmorated stink bug that has been plaguing the eastern part of the US damaging crops and invading buildings, but the stink bug that’s a problem for some area gardeners is a green stink bug. It’s feeding is causing yellowish to whitish cloudy spots all over tomatoes infested with stink bugs. Just beneath the skin of a ‘cloudy spot’ are clusters hardened white spongy cells. While still edible ,this makes the fruit difficult to peel and impairs their eating quality.

This is the time of year stink bugs residing in nearby weeds move to the garden to pierce ripening tomatoes. Scientists disagree exactly what causes the spots, but generally it’s believed that they inject a toxin into the fruit when they pierce it for its juices. There are a variety of different stink bugs that can cause this damage, but the one gardeners are bringing to me are bright green ‘Say’ stink bugs. These shield-shaped bugs are about .5 inch in length with orange spots at the base of the triangular back. The nymphs or young stink bugs are blackish in color. There are also brown stink bugs that can be found in the garden.

According to University of Utah bug experts, one stink bug per plant could cause 5-10% damage. That means that it doesn’t take excessive amounts of stink bugs to cause significant injury to garden tomatoes. If suspect you have a stink bug problem, the Utah expert indicated that you can find the culprits ‘by vigorously shaking the plant and examining the dirt beneath for fallen insects.’ Another hint that stink bugs are present is the brown liquid frass (yuck) that they leave behind as dried spots on the leaves and fruit where they’ve been feeding.

If you have a stink bug problem, control will not be easy. That’s because stink bugs don’t reside in the garden, but in weedy areas nearby, such as fence rows and ditches. Control involves eliminating weeds to prevent their overwintering and keeping weeds down during the gardening season. Potential overwintering hosts include Russia thistle, plantain, mullein, mustards, mallow, dock, blackberries, legumes, as well as other weeds.

In addition to good weed management, pesticides can be utilized for control but you should not only spray the vegetable garden, but also weedy areas that may be serving as stink bug havens. If you’re gardening organically, try using insecticidal soap sprays. Keep in mind that the soap sprays only affects the bugs to which it directly applied, so you’ll need to reapply soaps regularly.

There are also garden insecticides containing bifenthrin, permethrin, cyfluthrin, imidacloprid, or carbaryl that are effective against stink bugs. Be sure to find a product labeled for use in the vegetable garden, particularly tomatoes. If you use them on other vegetables or fruits be sure that they’re also listed on the label.

Some of these garden insecticides are highly toxic to bees. Be sure to follow all label directions and take the precautions needed to protect bees, wildlife, and yourself. Always check the label to find out how many days after spraying you must wait before you can safely harvest and consume (or preserve) the fruit. This may be labeled as ‘days to harvest’ or ‘pre-harvest interval’.

Finally, to answer another question that may be on your mind… yes, stink bugs do really stink. As a defense mechanism they have small glands on their body that emit a foul smelling liquid when threatened or mistreated. Eat one in a raspberry or hand squash them in the garden, and you’ll find out that they come by their name honestly.

Published: 8/3/2012 1:42 PM

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