WSU CAHNRS

Washington State University Extension

Garden Tips

Beetles RSS feed

ON THE WATCH FOR JAPANESE BEETLES

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.

WHAT’S THAT BEETLE EATING THE LEAVES OF MY PLANTS?

GARDEN TIPS – Written by Marianne C. Ophardt
WSU Extension Faculty
for the Tri-City Herald, Kennewick, WA Published June 5, 2016

In this area we can consider ourselves lucky that we have not had to deal with the voracious Japanese beetle. This leaf-feeding beetle is the scourge of gardeners in the eastern part of the US where it chows down on hundreds of species of plants. This includes vegetable and fruit crops, flowers, trees, and shrubs. The adult beetles skeletonize leaves by feeding on their upper surface and leaving only veins behind.

So far the Japanese beetle has not become a problem in Washington and the Washington State Department of Agriculture (WSDA) is trying to keep it that way. First, there is a quarantine on plant materials coming into Washington from infested parts of the country. WSDA requires that nursery stock and sod from these areas be inspected and certified to be free of Japanese beetle larvae or adults. That is why gardeners sometimes encounter a mail-order nursery that will not ship plants into our state. These nurseries do not want to take on the expense of getting their plants inspected for selling and shipping to Washington. To ensure that the quarantine is working, every year WSDA monitors areas of the state using Japanese beetle traps.

The rapacious Japanese beetle may not be a problem here, but there are other leaf feeding beetles that can be troublesome in our yards and gardens. The Colorado potato beetle attacks potatoes and its close relatives, including peppers, tomatoes, and petunias. When the Colorado potato beetle is present, there is no mistaking it. It is almost .5 inch long and .25 inch wide with a reddish head and a tannish-yellow and black-striped body. It damages potatoes by eating holes of varying sizes in the leaves, as well as feeding on leaf edges. Severe infestations can cause significant damage.

Those gardeners not wanting to utilize chemicals for control can try the “hands-on” approach by looking for and squishing any clusters of bright yellow eggs found on undersurface of the leaves and any adults and orange-red larvae found on the top of the leaves. Remove weeds in and around the garden because they may be serving as alternative food sources.

There are chemicals available for Colorado potato beetle management. These are most effective when applied as soon as the beetles are first discovered and again if needed. Be sure to treat the bases of the vine stems along with the leaves. (For chemical options go to WSU’s Hortsense website at http://hortsense.cahnrs.wsu.edu.)

Yet another leaf-feeding beetle can be a problem for area gardeners. Elm leaf beetles are only about .25 inch long with yellow-green and olive-green striped bodies. These guys and their yellow to green larvae feed on the undersurface of elm leaves, leaving the veins and the waxy upper surface of the leaves behind. In certain years these beetles are numerous and can effectively defoliate a tree. If this happens early in the season for several consecutive years it will stress and weaken a tree and possibly lead to its death. Luckily, the Elm leaf beetle population goes in cycles with high numbers some years and lower numbers other years.

It is difficult to control this beetle because its damage is often not noticed until after it has occurred. While there are chemicals available for management, a commercial pesticide applicator should be hired if the tree is above 10 feet tall. There are also systemic insecticide drenches that can be applied to the base of the trunk, but they should be applied prior to the appearance of the beetle damage.

BEETLES EATING UP ELMS

written by
Marianne C. Ophardt
WSU Extension Faculty
for the Tri-City Herald, Kennewick, WA
published – SEPTEMBER 5, 2014

BEETLES EATING UP ELMS

Have you been wondering why so many local elm trees are looking so sick? It is because large numbers elm leaf beetles have been dining on our elms this summer. Most elm owners do not notice elm leaf beetle damage until they are done feeding for the season. An adult beetle is about 1/4 inch long, olive-green, with two dark longitudinal stripes down its back. The larvae are yellowish green with black stripes and spots.

Both the adults and larvae of elm leaf beetles feed on elm leaves. Adult beetles eat holes in the leaves and the larvae skeletonize them, leaving only the veins and the waxy top layer of the leaf behind. The leaves then turn brown. If the population is large enough, they can defoliate a large tree by the end of summer.

Some species of elm are resistant to the elm leaf beetle. However, the Siberian elm (Ulmus pumila), the predominant elm found in many area landscapes, is not resistant. Siberian elm is a fast growing, large tree that reaches a height of 50 to 70 ft.

Dr. Michael Dirr, renown tree and shrub expert, says that the Siberian elm is “one of, if not, the world’s worst trees” because it is so messy and has brittle wood. Siberian elms produce prolific amounts leaf, branch, and seed litter, plus the tree is prone to limb breakage in wind and ice storms.

Add to long list of Siberian elm’s negative traits, the defoliation caused by elm leaf beetles. Because they are such tall trees, insecticide applications to control the beetles must be performed by licensed applicators. This is a costly service but may be worth it if the tree is of high value to the owner and if attacked repeatedly.

A less costly pesticide application is an insecticide drench applied to the soil at the base of the tree. However, this must be applied in late winter or early spring (before knowing if beetles will a problem or not) to be absorbed by the roots and moved systemically to the top of the tree. This movement can take four to six weeks or more and is dependent on water being applied to the soil regularly after application.

Elm leaf beetle populations have a tendency to fluctuate from year to year. In fact, it has been a number of years since we have experienced a severe elm leaf beetle outbreak in this area. Many insect populations tend to ebb and flow because of environmental conditions, the availability of food, and natural enemies. University of California experts note that more overwintering adult elm leaf beetles tend to die if winter weather is relatively warm or wet. Just because the beetles are causing damage this year, does not mean they will be a problem next year.

At the end of summer adult elm leaf beetles look for protected places to overwinter. “Protected places” include wall voids of nearby homes. In the spring they come out of hibernation and move back outdoors. However, some get lost and find themselves indoors. Vacuuming is the best method of control along with caulking cracks and wall voids to prevent their entry into the house in late summer.

I am wondering if the elm leaf beetles will be plentiful again next year, maybe not if we have a mild winter.

Published: 9/5/2014 12:32 PM

BUGS IN THE CUPBOARD

written by

Marianne C. Ophardt

WSU Extension Faculty

for the Tri-City Herald, Kennewick, WA

Did you take a sweater out this fall and find holes in it when there weren’t ones there when you put it away in the spring? Despite what you may have heard, the most likely culprits were carpet beetles…. not clothing moths, especially if it’s an acrylic sweater. Clothing moths are not a common pest in our region, but carpet beetles frequently find their way into closets, food cupboards, and other areas of the home.

There are two types of carpet beetles in our area, the varied carpet beetle and the black carpet beetle, with the varied carpet beetle being the most common. The varied carpet beetle is black with whitish uneven horizontal stripes. It’s a round little beetle that’s about 1/10 to 1/8 of an inch long. However, it’s not actually the adult beetles that cause the damage. They chow down on flower pollen outdoors. It’s their bristle-covered larvae that munch on and damage many things in our homes. These larvae are elongated, 1/8 to 1/4 inch in length, and brown and tan striped.

Carpet beetles like a protein diet, especially animal protein. In food cupboards, they’ll feed on products that contain protein… such as noodle mixes with cream or cheese sauce, dried milk, instant pudding, and cake mixes. They also are occasionally found in grain products. In closets they’ll feed on anything made from wool, silk, fur, hide, and feathers. Carpet beetles even feed on acrylic, linen, rayon, and cotton clothing that have been stored away without cleaning. Small spots of food or perspiration can leave a bit of protein for them to eat. They’ll also attack other items in your home… including dry dog and cat food, dead insects in light fixtures or window tracks, dog and cat hair, carpets, old book bindings, needlework made from wool or silk, animal trophies, and things made from bone and horn.

It’s the larvae that do the damage, but often neither the adult or larvae are detected in infested items. Instead, it’s the cast skins left behind when the larvae molt that are most frequently noted. If you find some of these cast skins, don’t panic. It’s not a sign of an unclean home. It just means you need to look for the source and clean it up.

The good thing about carpet beetles is that their populations don’t tend to build up quickly. Varied carpet beetles stay in the larvae stage for 220 to 630 days. They will be found in things that aren’t used very often… clothes that haven’t been worn for a while or food that got “lost” in the back of the cupboard.

Once discovered, an infestation can usually be cleaned up by getting rid of their food. This is as simple as throwing out any infested food products and thoroughly cleaning the cupboard. Do this by vacuuming cracks and crevices and then wiping the surfaces with soap and water. If it’s an item of clothing, it should be cleaned in the appropriate manner.

In some cases, you may have something that you can’t clean but don’t want to throw out, such as an ornament made from wool, an insect collection, or a trophy animal head. If it isn’t too big, the item can be placed in the freezer (below 32 degrees) and then removed and thawed. Repeat this three times at two day intervals. That will usually kill any carpet beetles and their larvae.

You can help prevent carpet beetle problems, by not storing food in your cupboard for long periods. Try to use up products in a timely manner. Throw them out if you don’t plan to use them again. If they’re unopened and still good, give them to a nearby food bank. Food that you want to keep for longer periods should be stored in the freezer or stored in a tightly sealed containers. Before putting winter clothing away for the spring and summer months, clean them as recommended by the manufacturer. Periodically check stored clothes and susceptible items for signs of infestation, especially if stored in an undisturbed area of the home.

You may wonder why we’re talking about “rug bugs” in a gardening column. One reason is that they may be brought into the house from the garden on cut flowers. During the warm, sunny days of summer the adults feed on the pollen of a variety of garden plants, such as spirea, dogwood, daisies, asters, and achillea. Attracted to light at night, the beetles can also find their way into homes through windows, doors, and other openings.

The other reason why I’m talking about carpet beetles is that, like it or not, I ‘m often asked about household pests and their control. With the onset of cold weather, some of you are probably finding holey clothing. Now you know to blame carpet beetles… not clothing moths.

Gardening Word of Caution: A gardener called me recently about the bad rash with blisters that she had developed after trying to remove snow-on-the-mountain from her garden. Another time, two young boys had played with the plant, putting it in their mouths, but not eating it. They developed serious blistering in their mouths. Plants in the euphorbia family have a milky latex sap that can cause skin rashes and blisters. This includes crown-of-thorns (houseplant), poinsettia, and snow-on-the-mountain (a flowering groundcover perennial). When pruning, pulling, cutting, or weeding around snow-on-the-mountain, it’s best to keep your skin covered and wear protective gloves and goggles to protect yourself from the sap. If you get the sap on your skin, wash it off right away.

With the holidays, many of us will have pretty poinsettias in our homes. While the poinsettia is not poisonous as it was once thought, it’s sap can be irritating to some. Keep them away from inquisitive children and pets.

Published: 11/27/2004 2:12 PM

WHAT’S BUGGING US NOW?

written by

Marianne C. Ophardt

WSU Extension Faculty

for the Tri-City Herald, Kennewick, WA

Two interesting insect phenomenon are bugging area residents. One of these is straight out of a horror movie. Thousands of big black beetles are on the move, marching down streets through yards all going in the same direction. This migration of beetles happens every year, but it’s only noticeable when the population of beetles is high and when the migration occurs suddenly.

The beetles being noticed are darkling beetles. Darkling beetles, also known as stink beetles (more about that later), belong to the genus Eleodus in the Tenebrionidae family of beetles. There are over 1400 species of this beetle family in North America, with most being found in the western part of the continent. They like sandy areas and are very common in desert and coastal regions. About 100 species of Eleodus are indigenous to the western United States, with at least 20 of those species living in our Mid-Columbia region.

As a group, darkling beetles are small to medium sized beetles, ranging in size from 1/16 to 1 3/8 inches in length. Most are black or dull brown. Their antennae tend to be segmented into 11 parts and slightly clubbed on the end. Their wing covers (elytra) are fused and often striated. Because their wings are fused they’re unable to fly, so to get from here to there they must walk. This makes them quite a slow moving beetle.

Darkling beetles are considered beneficial insects because they primarily eat decaying plant matter, such as dead leaves and rotting wood. They only occasionally eat live plant tissues. Most times their presence in yards, gardens, and the desert goes unnoticed, since they are ground dwellers. While active both night and day, they spend the hot part of the day in cool, moist, dark places, such as under rocks and garden debris.

I talked to Dr. Richard Zack, WSU Entomologist in Pullman, about this sudden mass migration being observed in our area. He said that it’s quite common for a number of darkling beetles species to migrate in large numbers in the fall. Some years this movement is more gradual, taking a couple of weeks to a couple of months and it goes by unnoticed. However, Zack notes that this year the abrupt change from hot weather to cooler conditions probably triggered the sudden mass migration being noticed by area residents. He also mentioned that most insect populations increase and decrease in cycles and it sounds like this is a “high” year for darkling beetles in the Mid-Columbia. Zack says if the weather would warm up again it would probably slow down the migration.

Now here is an especially interesting note about the darkling beetles… the reason they’re also known as stink beetles. If they’re disturbed or threatened they will point their rear end up in the air and emit a dark, foul smelling fluid. ( This liquid just kind of oozes out, it doesn’t get sprayed out.) The fluid is stinky enough to ward off potential predators, such as snakes, birds, rodents, raccoons, coyotes, and foxes. This is a particularly effective defense, especially for the large darkling beetle species. If you handle a darkling beetle, you may also encounter this icky, stinky juice, but it should wash off easily.

So while strange and interesting, this mass migration should not cause undue alarm. The beetle migration will soon be over and because they aren’t harmful, no control of their mass numbers is needed. If present in large numbers and causing a nuisance, sweep them up and get rid of them.

Yellowjackets are the other population of insects alarming area residents. While this insect is also considered to be beneficial, it’s a pest when it invades our living areas. They make it difficult to picnic outdoors at this time of year and can be found around garbage cans, car windshields, vineyards, fruit orchards, and anywhere else they can pick up a meal.

Why are there so many of them? In late summer and early fall, yellowjacket colonies are close to the end of the season and their workers are out looking for food for their queens. The queens are very important because they are the only yellowjackets that survive the winter. The rest of the colony dies. As summer draws to an end, their main source of food… other insects… becomes less available. This forces yellowjacket workers to find other sources of food. Plus, at this time of year their populations are at their highest, making competition for food fierce. The yellow jackets become very assertive and aggressive in gathering food. In the fall, they’re particularly fond of sweets, including soft drinks, fruit, and ice cream.

Sanitation and avoidance are your best options in dealing with a yellowjacket problem at this time of year. If dining outdoors, keep food and drinks covered until you’re ready to eat. Clean up any spills and put away leftovers as soon as you finish eating. If possible, dispose of your trash within closed plastic liners in trash cans with tight fitting lids. If there are leaks, be sure to clean your trash can. Remove and dispose of fallen and unwanted fruit from apple, plum, pear, and other types of fruit trees, as well as from grape vines. In parks, locate your activities as far away as possible from trash cans and dumpsters.

If you encounter yellowjackets outdoors, try to avoid a confrontation. Move carefully away, don’t automatically swat at them. Stay away from the fly swatter when involved in yellowjacket confrontations. Threatened yellowjackets give off an insect scent that warns other yellowjackets of the attack and summons them forth to provide assistance. Also, be aware that perfumes, hair products, and brightly colored clothing can attract yellowjackets. Check your open soft drink can before drinking… they will sometimes find their way inside when you’re not looking. This type of encounter is particularly dangerous.

Commerical yellowjacket lure traps are available at home and garden stores, but these traps provide little benefit at this time of year when yellowjacket populations are so high and will soon disappear with cold weather. However, if you decide to give them a try, locate them at the outer edges of the area you want to protect… to draw them away from where you will be eating or playing. Follow the label directions for the particular trap you purchase. If they call for a bait, some good ones include canned cat food, tuna, liverwurst, jelly, and fruit juice.

So what’s bugging you now?

Published: 9/18/2004 2:16 PM

PREDACIOUS GROUND BEETLES ARE OUR FRIENDS

written by

Marianne C. Ophardt

WSU Extension Faculty

for the Tri-City Herald, Kennewick, WA

If you pick up a flower pot set on the ground, it’s not unusual to find all sorts of nocturnal creatures hiding beneath it during the day. When you lift the pot, these little fauna scurry to find another dark place for protection. Some of these scampering fellows are likely to be predacious ground beetles. You may also occasionally find a lost ground beetle indoors, hiding under a laundry basket or pile of clothes in the laundry room. When encountered, the first reflex we have is to stomp on them.

Few of us feel like letting them go on their merry way, but you are encouraged to learn to recognize them as friends, not foes that need to be squashed. According to WSU Extension Entomologist, Dr. Arthur Antonelli, the different types of ground beetles found in Washington feed on a variety of “insects and insect-like creatures, many of which are garden or house pests, such as cutworms or house fly maggots. One specific group of ground beetles feeds on snails and slugs.” While they may also feed on some desirable critters, they are considered a beneficial insect because of the good they do.

Predacious ground beetles belong to a very large insect family of beneficial beetles called carabids (Carabidae family). Just in North America there are several thousand named species and over 40,000 in the world. They get the name of “ground” beetle because the majority of these beetles in temperate zones are terrestial, living close to the soil under pots, rocks, or garden debris, yet there are a number of tropical species that live above ground in trees.

To protect this valuable insect resource in your garden, you need to be able to identify them. Keep in mind there are numerous species and they don’t all look exactly alike. The ground beetles found in Washington range in size from one-eighth of an inch long to one and one-quarter inches long. They’re generally elongated with a body that tapers to a smaller head with long legs and long antennae. Most ground beetles we will encounter in our yards and gardens will be black or dark brown in color, but there are some that have more of a purple to metallic green appearance. These characteristics may be hard to verify because the beetles are quite fast, especially when scurrying for cover.

The ground beetle starts out life as an egg that hatches into a larva. It’s interesting that the larvae feed using “external digestion” where they spit their digestive juices onto their food, turning it into liquid nutrients. They then suck up the juicy digested matter. The larvae are worm-like, somewhat flattened, dark brown to cream in color, and a bit tapered at each end. Like the adult, the larva also has noticeable large mandibles (jaws). The larva then turns into a pupa before emerging as an adult. This all takes about a year for most of the ground beetles in Washington. Depending on the species, the adults may live for one to three years…unless some callous gardener flattens them with their shoe.

Dr. Antonelli notes that the four most common species of ground beetles in Washington are the European ground beetle , the green pubescent ground beetle, the common black ground beetle, and the boat-backed ground beetle. One of the ones most common in our region of Washington seems to be the common black ground beetle with lengthwise grooves on the wing covers over its back.

Dr. Antonelli cautions us that ground beetles are “often the victims of broad-spectrum insecticides used around the home and garden, especially when insecticides are used beyond an intended target plant or site.” When we apply pesticides to large areas, such as the foundation of the house, to reduce the population of a particular pest, we may be shooting ourselves in the foot by killing predators. Predatory insects, such as ground beetles, are responsible for helping us keep pest numbers down. It’s important to protect these valuable garden predators, not kill them. Predacious ground beetles are our friends.

Interesting Ground Beetle Trivia

Researchers and farmers at OSU

s Integrated Plant Protection Center have been developing “beetle banks” where they create raised beds four to six feet wide situated in the agricultural fields. These beds are planted with native bunch grasses and provide an area where ground beetles can thrive and eat harmful insects in crops planted nearby.

When threatened, many native species of ground beetles secrete stinky chemicals to deter animals from eating them. One such beetle is the”bombardier beetle” that emits toxic chemicals from its anal glands. These chemicals explode into puffs out the rear end of the beetle with an audible sound. It’s said to discourage frogs or other predators from eating them. I bet it does!

You can raise your own ground beetle to observe. Go to http://www.earthlife.net/insects/gb-care.html for information on how.

Published: 7/21/2008 2:46 PM

Archives

Categories

Garden Tips, WSU Extension, Benton County, 5600-E West Canal Drive, Kennewick, WA 99336-1387, 509-735-3551, Contact Us

WSU Extension, Franklin County, 1016 North 4th Ave, Pasco, WA 99301-3706, 509-545-3511, Contact Us
© 2017 Washington State University | Accessibility | Policies | Copyright | Log in