Posts tagged control

Good vs. Evil: Asian lady beetles and Japanese beetles

Asian lady beetle

Asian lady beetle - a good bug (photo/Cindy Hadish)

Their names are similar and they’re from the same region of the world, so I can see why some people are still confused about Asian lady beetles and Japanese beetles.  But when it comes down to it, there’s really no comparison. The bug pictured here – the reddish/orange lady beetle, is a beneficial insect. It feeds on aphids and other plant pests and doesn’t destroy anything, though I realize some people resent their intrusion in homes in the fall. On the other hand, the copper-colored Japanese beetle, a recent foreign invader in Iowa, is known to devour at least 300 plants, including hollyhocks, roses, raspberries, linden trees and grapes. If you see your leaves turning to lace, the likely culprit is the Japanese beetle.  Japanese beetles have no known predators here, other than me. So feel free to get rid of as many as you can. As mentioned previously, the most environmentally friendly method is to knock them into a bucket of soapy water when they’re sluggish – early evening seems to be the best time. If you have other suggestions – maybe from our East Coast readers and others who have learned to cope with Japanese beetles – please add your comments below.

Japanese beetles (photo/Cindy Hadish)

Japanese beetles - not a good bug, or just plain evil? (photo/Cindy Hadish)

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Japanese beetles are back

They’re back.

Japanese beetles

Japanese beetles

I spotted the first Japanese beetle of the season yesterday on my raspberry bushes. I went to check one of my rose bushes and sure enough, there was another one, sucking the life out of a beautiful pink bud. Unfortunately, both got away.

The beauty of these copper-colored beetles belies the devastation they wreak. Adult Japanese beetles feed on more than 300 types of plants – turning leaves into lacy skeletons. As larva, the white c-shaped grubs feed on turf grass roots.

I’ve heard some people have luck with the Japanese beetle traps that can be found at garden centers. Others say the traps just lure more beetles into your yard. When I see just a couple of the bugs, I use the squish method, but as they become more numerous, I’ll try to control their numbers with soapy water.

Take a small bucket with water and dish detergent – any kind will probably work – and knock the beetles off the plants into the bucket. The beetles are more active at certain times of day and will fly off. Othertimes, they do a drop and roll, which is the best way to get them to fall into the bucket. Early evening seems to be the time when they are more sluggish and easier to catch that way. Obviously, if you are growing crops that the beetles are attacking, such as grapes (another favorite,) you’re going to need a different method of control. They also favor certain trees, but supposedly they don’t kill the trees as do pests like the emerald ash borer. I also wonder what they will ultimately do to the monarch butterfly population, as Japanese beetles devastate the monarch’s food source, milkweed.

Since they make my top 10 bad bugs list, the Japanese beetle and different control methods can be found in several posts on this blog. Just use the search box at the right to find more from city arborist Daniel Gibbons, master gardeners and others on this foreign invader.

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Iowa’s weed season

   I’ve driven right past my plot in the city gardens, not recognizing it from what it was a week, or even days before. The rain and heat make the perfect recipe for weed season in Iowa. They grow fast and my combat methods are slower than the tillers many people use.

    Richard Jauron, extension horticulturalist at Iowa State University wrote the following about weed control in Iowa:

   Weeds are those annoying plants that gardeners love to hate. In the garden, weeds compete with desirable plants for water, nutrients, sunlight and growing space. They also may harbor insects and diseases. Allowed to run rampant in the garden, weeds can drastically reduce yields of fruits and vegetables. in addition, they hinder the performance of annual and perennial flowers.

    The first step in weed control is identification of the weed or weeds. The type of weed helps determine the best method of control. The two main types of weeds are annuals and perennials. Annual weeds germinate from seeds, grow, flower, set seed and die within one year. Perennial weeds live for three or more years. Most perennial weeds die back to the ground in fall, but their crowns or roots produce new shoots in spring. Weeds also can be classified as broadleaf weeds or grasses.

    There are three general methods of weed control in the home garden: cultivation (hoeing and tilling) and hand pulling, mulches and herbicides.

Cultivation and hand pulling effectively control most annual weeds. Perennial weeds are often more difficult to control. Repeated cultivation is often necessary to destroy some perennial weeds. When cultivating the garden, avoid deep tillage. The roots of many vegetables, fruits and flowers grow near the soil surface.  Deep cultivation will cut off some of these roots. Also, deep cultivation will bring deeply buried weed seeds to the soil surface where they can germinate. Hoe or till around plants or between plant rows, and pull weeds close to plants.

    To effectively control weeds, cultivation and hand pulling must be done periodically through the growing season. Small weeds are much easier to control than large weeds. It’s also important to destroy the weeds before they have a chance to go to seed.

    Mulches control weeds by preventing the germination of annual and perennial weed seeds. Established weeds should be destroyed prior to the application of the mulch. In addition to weed control, mulches help conserve soil moisture, reduce soil erosion, prevent crusting of the soil surface, keep fruits and vegetables clean and may reduce disease problems.

    Grass clippings, shredded leaves and weed-free straw are excellent mulches for vegetable gardens and annual flower beds. Apply several inches of these materials in early June after the soil has warmed sufficiently. Plant growth may be slowed if these materials are applied when soil temperatures are still cool in early spring. Grass clippings, shredded leaves and similar materials break down relatively quickly and can be tilled into the soil in fall.

Wood chips and shredded bark are excellent mulches for perennial beds and areas around trees and shrubs. Apply two to four inches of material around landscape plantings. These materials decay slowly and should last a few years. However, it’s often necessary to apply additional material annually to retain the desired depth.

   Herbicides can be used to supplement cultivation, hand pulling and mulches. However, several limitations prevent the extensive use of herbicides in the garden. Only a small number of herbicides are available to home gardeners. Additionally, most home gardens contain a wide variety of fruits, vegetables and flowers. No one herbicide can be safely used around all garden and landscape plants. If not applied properly, herbicides may cause unintended damage to fruits, vegetables and ornamentals. Herbicides are pesticides. When using any pesticide, carefully read and follow label directions.

Weeds are a persistent problem for home gardeners. However, weeds can be effectively controlled by cultivation, hand pulling, mulches and (on occasion) herbicides. Persistence is the key. Gardeners need to be as persistent with their weed control efforts as weeds are in coming back again, and again and again.

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Getting back to Earth

To some of us who grew up gardening, the process comes naturally. How can you not know how deep to plant a radish seed or realize you have to wait until the danger of frost has passed to plant your tomatoes? Actually, I’ve heard from people who grew up gardening and despise it now. That includes a couple editors here at The Gazette, who prefer to stay as far away as possible from watering cans, trowels, or anything else that reminds them of the back-breaking labor of their youth. 

   But, as mentioned in  today’s (4/19/09) Gazette article: http://www.gazetteonline.com/apps/pbcs.dll/article?AID=/20090419/NEWS/704199992/1002/NEWS

more and more people are moving toward gardening, as a way to help the Earth and save money on food budgets in these tough economic times. To that end, Iowa State University Extension has come up with a great beginner’s guide to home gardening, especially tailored for Iowa.

 

Even experienced gardeners will find helpful hints on beets, potatoes, squash and numerous other veggies, along with everyone’s favorite: weed control.

 

You can find the guide here: http://www.ipm.iastate.edu/ipm/hortnews/2009/4-8/introduction.html

 

 

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Ladybugs, Lady Beetles

   They are red, orange or shades in between and tend to invade homes in late fall.

   Ladybugs and lady beetles are different names for the same bug that some people see as a pest, but I see as a benefit. I don’t have the large-scale home invasion that some people do, so that could be why I see ladybugs through rose-colored glasses. When they do come indoors, I have a spot for them on my houseplants.

   My houseplants spend the summer outdoors and are given a good shower before I bring them inside in the fall. I don’t use any type of chemical insecticide, and that’s where the ladybugs come in: put them on the plants and they spend their days looking for tiny bugs to eat. They’re amazing to watch in action.

 I know my solution isn’t for everyone, so following are tips from Iowa State University about indoor control and other helpful information:

Ladybug in action

Ladybug in action

 

  The Asian lady beetle is present all summer but is most noticeable in the fall when second generation adults migrate from trees, gardens and fields to reflective, vertical surfaces (such as the south side of the house) in preparation for winter hibernation. 

 

   Asian lady beetles are a beneficial biological control in trees during the summer, and in fields and gardens during the fall, but can be a severe household nuisance during late fall and winter. Wooded residential and industrial areas are especially prone to problems.

   The origins of the Asian lady beetles are not clear, although it appears the current pest species was not purposefully released in the United States or in Iowa. Beetles that arrived by accident in ports such as New Orleans in the late 1980s have crawled and flown all by themselves to all corners of the country.

   The multicolored Asian lady beetle is 1/3 inch in length; dome-shaped; yellowish-orange to red with variable black spots on the back. Deep orange is the most common color. The 19 black spots may be faint or missing. There is a black “W” shaped mark on the thorax.

   Asian lady beetles, like other accidental invaders, are “outdoor” insects that create a nuisance by wandering indoors during a limited portion of their life cycle. They do not feed or reproduce indoors; they cannot attack the house structure, furniture, or fabrics. They cannot sting or carry diseases. Lady beetles do not feed on people though they infrequently pinch exposed skin. Lady beetles may leave a slimy smear and they have a distinct odor when squashed.

   Asian lady beetles follow their instinctive behavior and fly to sunny, exposed surfaces when preparing to hibernate through the winter. The time of beetle flight varies but is usually from mid-September through October (depending on weather.) Light colored buildings and walls in full sun appear to attract the most beetles.

   Sealing exterior gaps and cracks around windows, doors, eaves, roofs, siding and other points of access before the beetles appear can prevent unwanted entry. Experience suggests, however, that comprehensive pest proofing is time-consuming, often impractical and usually not 100% effective.  For large infestations with intolerable numbers of beetles, spraying pyrethroid insecticides such as permethrin or esfenvalerate to the outside of buildings when the beetles appear may help prevent pest entry. Homeowner insecticides other than pyrethroids usually do not provide satisfactory prevention.

   Long-term relief may come from planting trees that will grow up to shade the south and west sides of the house. The most practical control for beetles already inside is to vacuum or sweep them up and discard. Indoor sprays are of very limited benefit. Interior light traps are available.

Donald Lewis, of Iowa State University’s Department of Entomology, adds the following about ladybug myths and facts:   

Myth: Ladybugs are different from lady beetles

Fact: Ladybugs and lady beetles and ladybird beetles are all different names for the same thing.

Myth: Asian lady beetles come from soybean fields.

Fact: There are Asian lady beetles in soybean fields, but also many other places including trees and, gardens.

Myth: Soybean harvest causes multicolored Asian lady beetles to migrate to town and to houses.

Fact: Day length and temperatures trigger migration – expect swarms of beetles on first warm days after frost. Soybean plants lose their leaves, and therefore any aphids the lady beetles might be eating long before harvest. The beetles leave soybean fields as the plant leaves begin to turn yellow and not when the combines arrive.

Myth: Farmers released the lady beetles to eat the soybean aphid

Fact: No releases were ever made in Iowa. Multicolored Asian lady beetles arrived in Iowa by wandering from adjoining states several years before the soybean aphid appeared.

Myth: Lady beetles breed in the walls of the house during the winter.

Fact: They do not reproduce during the winter.

Myth: Finding a ladybug brings good luck.

Fact: This myth might not be all wrong. Since ladybugs eat aphids, other small insects, mites and the eggs of insects and mites, you could argue that ladybugs do bring good luck to farmers and gardeners. However, there is no evidence to prove that the good luck extends beyond the benefit of fewer aphids feeding on your plants.

Myth: You can tell the age of a ladybug by counting its spots.

Fact: There are over 5000 different species of lady beetles (ladybugs) in the world and approximately 475 species in North America. There may be as many as 100 different kinds in Iowa. The numbers and arrangements of spots on the backs of ladybugs are distinctive for the different species, and once a lady beetle emerges as an adult it never changes its spots.

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Centipedes, millipedes and more Japanese beetles

 

 

Master Gardener Intern, Sue Levasseur, answers two questions frequently asked of the Hortline:

 

            Q.  How can I get rid of those metallic-green bugs that are eating my plants?

The Japanese beetle has become a significant pest in Iowa during the past decade.  The head and thorax are shiny metallic-green, and the wing covers are coppery red. A row of five tufts of white hairs grow on each side of the abdomen.

            Japanese beetles are a double threat insect in the home garden.  In the larvae stage they are white C-shaped grubs that are approximately 1¼” long when fully mature.  They inhabit the soil from August until June where they feed on turf grass roots and organic matter.  Adult beetles emerge in June and eat the foliage and flowers of over 300 plants.  Foliage is consumed by eating the tissue between the veins, a type of feeding called skeletonizing.

            Control of adult beetles is difficult because they emerge every day for a period of several weeks.  Handpicking or screening of high-value plants may be of benefit in isolated situations with limited numbers of beetles.  Spot spraying infested foliage of high value plants with carbaryl (Sevin), permethrin (Eight) or cyfluthrin (Tempo) may reduce damage for several days but multiple applications are required to maintain control.  Spraying the adult stage is not an effective strategy for prevention of white grubs.  Use of floral lure and sex attractant traps is not recommended; research suggests that they are not effective in controlling moderate to heavy infestations and they may attract more beetles into a yard than would occur otherwise.  However, the traps may reduce damage and beetle populations where landscapes are isolated from other Japanese beetle breeding areas or when mass trapping (everyone in the neighborhood) is used.  

            Q.  What is the difference between centipedes and millipedes and how can I get rid of them in my house?

            House centipedes are approximately 1½” long with 15 pairs of long, threadlike legs extending from their body segments (one pair per segment). In contrast, millipedes are about 1¼” long and have 30 pairs of short legs extending from their body segments (two pair of legs per segment). 

            House centipedes are found both indoors and outdoors, but prefer living in damp portions of basements, bathrooms, and unexcavated areas under the house.  They feed on small insects, insect larvae and spiders.  Thus they are beneficial and considered harmless to people but most homeowners consider them a nuisance.

            To deter centipedes from your home dry up and clean the areas that serve as habitat and food source for centipedes as much as you can.  Residual insecticides can be applied to usual hiding places such as crawl spaces, dark corners in basements, baseboard cracks, openings in concrete slabs, under shelves and around stored boxes.

            Millipedes are usually found outdoors where they feed on decaying vegetable matter.  They are one of nature’s harmless “recyclers”.  Millipedes are accidental invaders in the house.  Capture and discard the offending invader.

Gardening Questions?  Call the Linn County Master Gardener Horticulture Line @ 319-447-0647.

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Beetle Battle II – Japanese beetle invasion

 

     I don’t hide my disdain for the Colorado potato beetles that annually devour my potato crop, but come July, I’m battling a much more formidable foe.

    The deceptively handsome, copper-colored Japanese beetles are out in force, their voracious appetites turning foliage to lace throughout my backyard.

    As obnoxious as they are, potato beetles are at least slower moving, and thus easier to squish than the wily Japanese beetle.

    Japanese beetles have perfected the art of stop, drop and roll, and if that fails, while I’m reaching in for the death kill, they simply fly away.

    Their favorite meals appear to be grapes, hollyhocks, roses and – where we do most of our battle – raspberry bushes.

    Armed with a single gardening glove and a container for whatever raspberries they haven’t devoured, I make a trek to the bushes every evening after work.

    Early evening seems to be the time when they are less likely to fly off and are an easier target for my gloved hand.

    When one or two started appearing on the bushes in late June, this “squish” technique seemed to work, but by now, several of the beetles gather on each leaf and it’s time to move on to bigger things.

    Because raspberry patches should be a place where you or a child can readily eat whatever’s ripe, as-is, I wouldn’t use any chemical means of control. The best approach has so far been to take a small bucket of soapy water  to the bushes – I use liquid dish soap – and knock the beetles into the water.

    Plain water doesn’t quite do the trick, as the beetles can survive, swimming around, for at least several days in it.

    I’ve heard bug experts say Japanese beetles usually don’t kill anything before they end their midsummer’s rampage, but I don’t know that they’ve seen the infestation problem that my backyard seems to have.  Once the beetles ravage their favorite plants, they will move on to almost any others available. They even suck the flowers of my fragrant milkweed to nothing.

    I’m envious of the parts of the country where these beetles have not yet reached. Even areas of Cedar Rapids seem immune to the problem. If you’ve had any luck with other methods of control, please let me know.

 

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