Nursery, Turf, and Landscape - DNLA Summer Turf and Nursery Expo

The following is information on the upcoming Delaware Nursery and Landscape Association Summer Turf and Nursery Expo.

Delaware Nursery & Landscape Association

22ND ANNUAL SUMMER TURF & NURSERY EXPO and 10TH ANNUAL GOLF TOURNAMENT

Date: August 13, 2009
Time: 8:30-1:15 for program, golf afterwards
Location: Jonathan's Landing Golf Club, Magnolia, DE
Address: Jonathan’s Landing Golf Course, 1309 Ponderosa Drive, Magnolia, DE, (302) 697-8204
Lunch: A Hearty Picnic Luncheon Will Be Provided.
Credits: 2 Delaware pesticide applicator recertification credits will be awarded. Credits for PA and MD will also be available.
Registration: Preregistration is required, printable form is in the post that follows this announcement

SPEAKERS / WORKSHOPS

1) Permeable Paver Installation
Learn the installation process and how to capitalize on this growing market.
Ross Causey, Garden Square Landscaping, Shane Robinson, EPHenry

2) Options for Wet Areas - I’ve got a wet area…now what?
Bill Haldeman, Flintwoods, Mike Weaver, Flintwoods

3) Weed, Pest, & Disease Identification*
Join Brian & Bob for a smorgasbord of problematic possibilities in the annual identification challenge, and methods of control.
Brian Kunkel and Bob Mulrooney, University of Delaware

*Pesticide Credit

Nursery, Turf, and Landscape - DNLA Summer Turf and Nursery Expo Registration Form

The following is the 2009 DNLA Summer Turf and Nursery Expo Registration Form.

CLICK ON FORM FOR A LARGER IMAGE TO PRINT

Greenhouse and Nursery - Handling Media

The following is a reprint of a good article on handling growing media.

How a mix is handled can affect the air and water content of the mix. Compaction is an important factor to consider for plant root health when handling growing media. Air space that results in good drainage can be cut in half or even eliminated by compaction. To minimize compaction, containers, cell packs and plug trays should be lightly filled and the excess brushed away. The media should not be packed down, tamped down, or the filled pots tapped down on the bench several times, and the pots and trays should not be stacked directly over one another.

Another consideration is the moisture content of the mix prior filling containers. When water is added to dry components such as peat, they hydrate and swell. This swelling helps to create more aeration by preventing the particles from nesting within one another. This is especially important in plug production. Water should be added to the mix before it is placed into the container. It is best to moisten, then mix and then allowed to set overnight prior to use. If that is not possible, waiting at least a couple of hours after adding the water will help the hydration process.

How much water to add to the mix? For peat-based mixes for large containers and bedding plant cell pak production use 1 water:1 dry substrate ratio (50% moisture content). Plug mixes should have 2 water:1 dry substrate ratio (67% moisture content). The rule of thumb is, the smaller the cell, the more water to add prior to planting.

Information from the New England Greenhouse Update Website:
http://www.negreenhouseupdate.info/index.php/search-form/214-handling-growing-media

Greenhouse and Nursery - Check Your Fertilizer Injector

Fertilizer injectors should be checked for accuracy on a regular basis. The following is a simple procedure to follow for checking your injector.

Procedure to check the EC of a fertilizer solution:

1) Let plain water (no fertilizer) run a little, then collect water in a clean bucket. Take a sample of the plain water from the bucket. Check the EC of the untreated water supply.

2)Mix up your fertilizer as you normally do and run it through the injector and hose. Let it run a little to be sure you get an accurate sample. Take a sample of the fertilizer-injected water from the end of the hose and use your meter or soil test laboratory to check the EC of the sample.

3) Subract the EC value of the untreated water from the EC value of the fertilizer water.

4) Compare the results to an EC chart from the fertilizer manufacturer or fertilizer bag. The chart will correlate the EC measurement with the ppm Nitrogen so you can determine if your injector and mixing procedure is accurate.

Information from the New England Greenhouse Update Website
http://www.negreenhouseupdate.info/index.php/search-form/241-checking-your-fertilizer-injector

Landscape - Generalist Caterpillars

There are a number of generalist caterpillars that can attack landscape plants, especially annual and herbaceous perennial plants. The following is more information.

A number of caterpillar species will feed on ornamental plants in the landscape. These include the well known pest such as bagworms, fall webworms, and eastern tent caterpillars. However, some pests more commonly associated with agricultural crops will also feed on ornamental plants. These include corn earworms, cutworms, various loopers, pansyworms, hornworms, and others. These are generalist caterpillars that readily feed on many plant species. Look for them on herbaceous perennials and annual bedding plants in particular. Caterpillar damage to bedding plants can be distinguished from slug or beetle damage because caterpillars generally consume large areas of leafs including all but the largest veins. Slugs will leave a messing trail of slime and feeding damage will appear irregular. Caterpillars in hanging baskets and small plantings can often be removed by hand. Commercial operators have a number of chemical options to choose from including the pyrethroid and spinosyn class insecticides.

Adapted from an article in the current North Carolina Pest News http://ipm.ncsu.edu/current_ipm/09PestNews/09News14/pestnews.pdf

Landscape and Nursery - Baldcypress Rust Mite

Baldcypress rust mite is evident now on Baldcypress trees in Delaware. The following is more information.

Baldcypress rust mite (BCRM). Even with the wet spring, Taxodium foliage may be showing the russetting, bronzing, distortion, and premature leaf drop that are telltale symptoms of BCRM damage. Look for the white cast skins of these microscopic yellowish-brown with a hand lens. BCRM overwinters as mated females in bark cracks and buds of baldcypress. After bud break, females migrate to needles and lay eggs. Populations build up rapidly in warm weather and typically peak in late July to Mid-August. BCRM feed until about needle drop in mid-October, when they re-position for overwintering. Use funnel sampling to scout for BCRM and other spider/rust mites.

No need to manage BCRM in the landscape, if premature browning and leaf drop is tolerable. Treatment is warranted in container and field nurseries. Several natural enemies feed on BCRM-predatory mites, predatory thrips, and spider mite destroyers (a small lady beetle - Stethorus spp.) are a few. We found that populations of BCRM were best managed using 1250 GDD or petal fall of Kousa dogwood as early indicators. We're past that now…

2% (v:v) horticultural oil the best chemical control for BCRM. While several other researchers have noted phytotoxicity from its use on baldcypress, our mid-season oil applications have reduced BCRM without burn and may provide lecanium scale crawler control as well. Attempts to manage BCRM in the dormant stage with oil applications actually INCREASED mite populations during that season and should be avoided. Avid (abamectin) or Forbid (spiromesifen) are other miticidal choices for later in the season, but will harm some natural enemies. Many newer selective miticides such as Hexygon and Floramite have NO EFFECT on rust mites, so check the label.

Information from Casey Sclar, IPM Coordinator, Longwood Gardens

Landscape - Current Pests

The following are some current pest reports from the Ornamental's Hotline newsletter from Delaware Cooperative Extension.

We are still seeing twig dieback from earlier infections of bacterial blight on willow oak, pear, and cherry. Trim back at least 12 inches below the affected area when dry. With all the lush new growth (Saturday's sprinkle followed by sunny days), be on the lookout for aphids and whiteflies infesting the new growth of annuals and perennials. Japanese beetle populations are much lower than expected so far this year. Azalea whitefly was noted on deciduous azaleas. More lace bugs starting up on Franklinia, oak, and other species; 2nd generation Euonymus scale crawlers should be active anytime. Hort oil (as temps permit), insecticidal soap, Distance, Safari are all good options for control. Brian Kunkel (bakunkel@udel.edu) is still looking for sites with Euonymus scale infestations.

Landscape - Invading Millipedes

Each year I get samples of millipedes that are invading houses and other structures. The following is an article on the subject. Commercial landscape companies may be asked to deal with the problem.

Millipedes are long, many segmented creatures that use their two pairs of legs per body segment to move along with deliberate speed. There are several species in Delaware with a variety of shapes and colors.

Millipedes can be very abundant in forest litter, grass, thatch, and in mulched areas. These places provide needed food, shelter, and dampness. Usually, millipedes stay out of sight unless abundant rainfall or some other event, such as the mating season, puts them on the move.

While harmless and in fact, helpful recyclers, millipedes generally are not welcomed with enthusiasm. They often invade crawl spaces, damp basements and first floors of houses at ground level. Common points of entry include door thresholds (especially at the base of sliding glass doors), expansion joints, and through the voids of concrete block walls. Frequent sightings of these pests indoors usually mean that there are large numbers breeding on the outside in the lawn, or beneath mulch, leaf litter or debris close to the foundation. Because of their moisture requirement, they usually do not survive indoors for more than a few days.

Managment

Minimize moisture & remove hiding places - The most effective, long-term measure for reducing entry of millipedes is to minimize moisture and hiding places, especially near the foundation. Leaves, grass clippings, heavy accumulations of mulch, boards, stones, boxes, stacked firewood or similar items laying on the ground beside the foundation should be removed, since these often attract and harbor pests. Items that cannot be removed should be elevated off the ground.

Seal entry points - Seal cracks and openings in the outside foundation wall, and around the bottoms of doors and basement windows. Install tight-fitting door sweeps or thresholds at the base of all exterior entry doors, and apply caulk along the bottom outside edge and sides of door thresholds. Seal expansion joints where outdoor patios, sunrooms and sidewalks abut the foundation. Expansion joints and gaps should also be scaled along the bottom of basement walls on the interior to reduce entry of pests and moisture from outdoors.

Insecticides - Exterior applications, in the form of barrier sprays, may help to reduce inward invasion when applied outdoors, along the bottom of exterior doors, around crawl space entrances, foundation vents and utility openings, and up underneath siding. It also may be useful to treat along the ground beside the foundation in mulch and ornamental plant beds, and a few feet up the base of the foundation wall. Heavy accumulations of mulch and leaf litter should first be raked back to expose pest hiding areas. Insecticide treatment may also be warranted along the interior foundation walls of damp crawl spaces and unfinished basements. There is no benefit from treating indoors.

One species of millipede. Photo by Gary Alpert, Harvard University, Bugwood.org.

Adapted from "Millipedes and Wood Cockroaches - Common Invaders in July" By Lee Townsend in the current edition of the Kentucky Pest News http://www.uky.edu/Ag/kpn/kpn_09/pn_090714.html

Landscape - Peony Blotch

The following is information on Peony blotch, a common disease of Peony in Delaware.

Peony blotch is now evident on garden and tree peony. Look for purple to dark red spots on the upper surface of the leaves and the corresponding lower surface will be chocolate brown color. The fungus, Cladosporium, will also infect the stems and produce circular spots with red borders. Be sure to remove and destroy infected leaves and stems in the fall to reduce overwintering spores. It's too late for any fungicide control this season unless you are just seeing the first blotches. The disease does not seem to affect plant health all that much, just makes a mess of the leaves.

Information from Bob Mulrooney, Extension Plant Pathologist, UD

Landscape and Nursery - Sucker Control

The following is information on sucker control in woody plants.

Many ornamental trees and shrubs will produce suckers from the stem area at the base of a plant, some from the roots. In multi-stem shrubs, these suckers will provide new stems and can serve as a means to rejuvenate plants (remove old stems, keep some new stems). However, in most trees and single stem shrubs, suckers are a drain on plant food reserves and can attract pests. In grafted plants, suckers from rootstocks will be different from the desired ornamental plant. Sucker removal by hand pruning can be time consuming in nurseries and large landscapes.

There are some chemical aids to reduce or eliminate suckers. Naphthaleneacetic Acid (NAA), a growth regulator, is labeled for some non-residential uses on ornamental plants. Apply in the dormant season or before new shoots are 12’’ long. Pelargonic acid (Scythe) is a non-selective herbicide that can be applied to suckers of woody plants. It can be used in landscapes and nurseries. Use a 5-10% solution. One caution is not to use glyphosate (Roundup and many other trade names) for sucker control or around plants with suckers. The glyphosate will be translocated into the root system of the plant and while you may not see any affect to the main plant this year, in the following year, the glyphosate will be mobilized from the root system and translocated to growing points causing poor leaf out, yellowing, reduced growth or stunting.

Gordon Johnson, Extension Agriculture Agent, UD

Landscape - Verticillium Wilt

As drier weather sets in, evidence of wilting in some tree species may be seen. One cause of wilting is Verticillium wilt, a fungus disease. The following is more information.

Verticillium wilt of woody plants is caused by the fungus Verticillium dahliae, or in some cases by V. albo-atrum. The fungus is capable of causing a serious vascular wilt of a wide range of woody plants. Several of our common landscape trees such as ash, katsura tree, magnolia, maple, redbud, and tuliptree are susceptible to Verticillium wilt.

Symptoms. By invading the xylem tissues of the tree, Verticillium disrupts the movement of water from the roots to the leaves. As a consequence, leaves wilt and branches die back. This often occurs one branch at a time or on one side of the tree over a period of several years, but sometimes in only a matter of months or a year. Sometimes, branches simply fail to leaf out in the spring - the result of infection the previous year. Verticillium wilt may also cause marginal browning and leaf scorch, abnormally large seed crops, small leaves, stunting, poor annual growth, and sparse foliage. However, some or all of these symptoms may also be caused by girdling roots, construction injury, bacterial leaf scorch and drought.

In the landscape and nursery, one should try to observe additional diagnostic symptoms. Usually, there is staining of xylem and cambial tissue, visible as streaks if you cut into the wood. The color of this staining will vary for different trees often being greenish black in maple, yellowish green in smoke tree, dark brown in redbud, and brown in ash and catalpa. Be aware that often young twigs and branches and some tree species simply don’t show the streaks of stained xylem tissue under the bark and that other fungi and other factors can cause staining. For a positive laboratory diagnosis of Verticillium wilt, stained vascular tissue is essential.

Disease biology. The Verticillium fungus survives as resistant, dormant microsclerotia for many years in soil, making effective crop rotation in the nursery or landscape difficult. The fungus infects plant roots through wounds, or in some cases, direct penetration of susceptible root tissue. In the nursery, the Verticillium fungus could also be transmitted from plant to plant by grafting and budding. From the root infections, the fungus spreads into the plant through the xylem. Xylem tissues become blocked so that stems and leaves no longer are supplied with adequate water and mineral elements. After the tree dies, the fungus is returned to the soil as tiny resistant fungal microsclerotia. Microsclerotia can also be spread by wind, in soil, and on equipment. Many herbaceous and weed hosts are also susceptible so it is hard to avoid contaminated soil. Verticillium wilt is favored by landscape stresses such as wounding and drought. It is possible that much of the Verticillium observed now relates back to stresses imposed by the drought last summer.

Reprinted from "Verticillium Wilt is Active in Catalpa and Smoke Tree" By John Hartman in the current edition of the Kentucky Pest News. For the full article with pictures go to http://www.uky.edu/Ag/kpn/kpn_09/pn_090714.html

Landscape - Managing Verticillium Wilt

Relating to the recent post on Verticillium wilt in trees, the following are points to consider in managing Verticillium wilt.

1) Where Verticillium wilt has been diagnosed, only replant with disease resistant plants. Conifers such as hemlock, pine, taxus and spruce are not affected. Other trees that are typically free of this disease include: beech, birch, crabapple, mountain ash, dogwood, hackberry, hawthorn, hickory, holly, honeylocust, mountain ash, oak, pear, planetree, sweetgum, sycamore, willow, and zelkova. The red maple cultivars Armstrong, Autumn Flame, Bowhall, October Glory, Red Sunset, Scarlet and Schlessinger have also been reported as resistant.

2) Keep plants as healthy as possible. Good plant health care includes good site selection, proper transplanting, good water management, a prudent fertility program, and pruning out dead branches. Be aware that while pruning out infected branches is a useful general horticultural practice for maintaining plant vigor and aesthetics, it does not eliminate Verticillium from the plant since infections originate and spread from the roots.

3) Fungicides are not effective for control of this disease.

Information from the an article by John Hartman, UK Plant Pathologist, in the current edition of the Kentucky Pest News http://www.uky.edu/Ag/kpn/kpn_09/pn_090714.html

Landscape - Cicada Killers

Cicada killers in the landscape can get home owners worried due to their large size and excavation they do in the landscape. The following is more information.

Now that cicadas are out, soon to follow are the wasps that hunt them. The cicada killer wasp uses cicadas to provision its nest. Cicadas are caught and stung by the wasp, then dragged back to the nest. The most noticeable feature is often the large amount of soil excavated and mounded outside the burrow. Once in the nest, the female wasp lays her eggs on the cicada. Soon the egg hatches and the larva feeds on the cicada. When mature, the wasp larva pupates and another generation of wasps emerges to carry on the life cycle. This is one of our most "showy" wasps and the sight and sound of a collection of them in a yard is impressive. I used to say that I had never heard of anyone being stung by one until a woman from Texas sent me an e-mail message to say that she had, indeed, been stung. However, it was really an accidental entanglement that created the situation. She seemed only slightly amused to know that she held such an honor. Since they control cicadas, these wasps can be regarded as beneficial. They are also downright interesting. Ornamentals and Turf Insect Note No. 63 (http://www.ces.ncsu.edu/depts/ent/notes/O&T/lawn/note63/note63.html) has additional information on the biology and control of cicada killer wasps.

Cicada killer wasp and cicada. Photo by Ronald F. Billings, Texas Forest Service, Bugwood.org

Information from the July 10, 2009 edition of the North Carolina Pest News http://ipm.ncsu.edu/current_ipm/09PestNews/09News13/pestnews.pdf

Turf - Controlling Nutsedge

The following is information on controlling Nutsedge in Turf.

Control options for the homeowner are rather limited; look for products with the active ingredient sulfentrazone or halosulfuron. Yellow nutsedge control options for professional applicators include Dismiss (sulfentrazone) and Sedgehammer (a.i. halosulfuron). Repeat applications will likely be required to achieve control. As with any herbicide applications at this time of year, be cautious of applications to turfgrass that is under drought or heat stress, even with the relatively cool temperatures, the soil is drying out in many areas and the turf is starting to show some stress. General recommendations are to avoid herbicide applications when temperatures are above 80 F due to the risk of burning the turf. Sulfentrazone has been implicated in causing damage to tall fescue turf in some cases, especially when applied with urea fertilizers.

Information in part from the Michigan State University Landscape Alert Site http://ipmnews.msu.edu/landscape/

Nursery and Landscape - Controlling Suckers

Controlling suckers in woody plants in the nursery can be time consuming by hand. There is a chemical option that could also be used in large landscapes. The following is more information.

We have had several questions on what materials to use to burn back sucker shoots on nursery plants. The wet season has resulted in a proliferation of sucker shoots. First off, do not try to use glyphopate to burn back sucker shoots. This will translocate into the plant and will cause bark splitting and possible dieback of the plant. Pelargonic acid sold as the product Scythe from Dow AgroSciences Company, can be used to burn back sucker shoots Avoid using this material on young trees with green bark. The material is applied to the sucker shoots before they become woody. The percent used is between 5 and 7%. The 5% rate is 2 quarts in 10 gallons of water. The 7% rate is 2 3/4 quarts in 10 gallons of water.

Information from the University of Maryland TPM/IPM Weekly Report for Arborists, Landscape Managers & Nursery Managers

Turf - Rutgers Turf Field Days

The following is information on turf field days coming up at Rutgers University.

Turf Field Days at Rutgers

Mark your calendars now for this year’s Rutgers Turfgrass Research Field Days which will be held on August 4, 2009 (Golf and Fine Turf Research Field Day at Horticultural Farm II, New Brunswick, NJ) and August 5, 2009 (Landscape and Sports Turf Research Field Day and Equipment Demonstrations at Adelphia Research Farm, Freehold, NJ). Additional information, on-line registration and directions to each location may be obtained at www.njturfgrass.org

Landscape and Nursery - Daylily Rust

The following is information on daylily rust, a relatively new introduced disease that can attack daylilies.

Daylily Rust

The recent introduction of a new disease has complicated the nearly trouble-free reputation of daylilies. Daylily rust, caused by the fungus Puccinia hemerocallidis, produces yellow spots or streaks on leaves and scapes, with raised pustules commonly on the undersurface releasing infectious orange spores. The frequently seen Daylily Leaf Streak, caused by the fungus Aureobasidium microstictum, begins with water-soaked brown spots usually beginning at the top of the leaf. As these work their way downward, they lengthen into brown streaks with yellow borders. A quick way to confirm Daylily Rust as the problem is to wipe a clean white tissue over the leaf lower surface – an orange stain indicates the presence of the rust spores. A severe infection on susceptible varieties may result in withering and death of the leaves, but the crown and roots are not involved.

As with other rusts, P. hemerocallidis has a life cycle that features two hosts, though it requires only the daylily to survive asexually from year to year. On daylily, the fungus produces two kinds of infectious spores – the orange urediospores, spreading disease during the growing season to other daylilies, and the darker, thicker-walled teliospores. These can survive the winter and infect the alternate host to complete the life cycle with the sexual stage. The alternate host is Patrinia, a perennial with fern-like leaves and bright yellow umbels, sometimes used as a filler for border plantings. No infection of Patrinia has been observed in the US, however, and the fungus can infect other daylilies without infecting the alternate host. Reports that Hosta can act as an alternate host have not been verified.

On daylily, disease spread is favored by warm temperatures and high humidity. Cloudy rainy weather is best. Poor air circulation and overhead watering at night should be avoided. Spores can spread by wind, windblown rain, or mechanical transfer by clothing or tools, for example.


Management: Select varieties that are more resistant.

The following list is from the Texas Cooperative Extension, Texas A & M University, April, 2004. Destroy infected leaves and those of nearby plants.


Remove shoots as close to the ground as possible. Fungicide sprays can be used when new growth emerges. In the fall, remove foliage from all plants and destroy or compost these (hot compost temperatures will eradicate the urediospores). If you are planting newly purchased daylilies in the spring, prune them back to remove possible inoculum from your landscape. Fungicides available to commercial growers for managing this disease include azoxystrobin (Heritage), propiconazole (Banner Maxx), myclobutanil (Systhane), thiophanate methyl (Cleary’s 3336 and others) or flutolanil (Contrast). Follow all label directions.

Reprinted from an article by Penny Wolkow in the July 10, 2009 edition of the TPM/IPM Weekly Report for Arborists, Landscape Managers & Nursery Managers from the University of Maryland Cooperative Extension http://www.ipmnet.umd.edu/09Jul10L.pdf

Landscape - Twobanded Japanese Weevil

The following is information on twobanded Japanese weevil. Adults will be emerging during the summer in DE.

Twobanded japanese weevil adults [1267- 1897 (1555 peak) GDD base 50] feed on ash, cherry laurel, pyracantha, privet, rose, spirea, forsythia, lilac, barberry, flowering dogwood, broad-leaved evergreens, and others. This flightless weevil is light to dark brown and feeds during the day on new leaves, shoots and inner foliage, but drops to the ground when disturbed.

Remove excessive mulch to prevent overly moist soils around susceptible plants. Entomopathogenic nematodes, Heterorhabditis and Steinernema spp., offer variable control of larvae in field plots but have performed better in container soil in greenhouses. Adult chemical control includes acephate, pyrethrins, piperonyl butoxide, and cyfluthrin and imidacloprid. The twobanded Japanese weevil is resistant to sevin and malathion.

Twobanded Japanese Weevil adult. Photo from the University of Georgia Archive, University of Georgia, Bugwood.org

Information from Brian Kunkel, Ornamental IPM Specialist, UD

Green Industry Professional Field Day and Trade Show

The following is information on an upcoming Green Industry Professional Field Day and Trade Show being held at American University in Washington D.C.

Green Industry Professional Field Day and Trade Show at American University

Date: July 16, 2009
Pre-registration: $55.00 each by July 11, 2009 mail and 7/13 online. To register online visit www.greenindustryseminar.org
Information: For more information call (703) 250-1368, email greenisdc@aol.com or visit
www.greenindustryseminar.org to register online.

Green Industry Professional Field Day and Trade Show

Hands-on, outdoor demonstrations presented at the beautiful campus of American University, Washington, DC on a July Thursday each year. This campus is an official arboretum, with a vast array of plantings for you to enjoy. Each year we feature new, unique presentations showing the latest developments in the industry.

Demonstration Topics, arranged in four tracts, range from athletic turf subjects to grounds maintenance to aerial rescue in the mature trees of the Quadrangle. See new plant introductions and participate in landscape design discussions. One tract is presented in Spanish for the continuing education of the diversified workforce. Please consult the brochure for the complete listing and details.

To download the 2009 Brochure with Registration form, please follow this link: 2009 Field Day Brochure

Landscape - Black Vine Weevil

Black vine weevil will be laying eggs soon in the landscape. The following is more information of this pest which is a big problem on Rhododendrons in DE.

Black vine weevil adults [87-3644 (1259 peak) GDD base 50] feed on over 100 plants such as Taxus, hemlocks, euonymus, mountain laurel and rhododendrons. Magnolia x soulangiana in full bloom signals the beginning of adult activity. This flightless weevil feeds during the night and rests at the base of plants during the day. Adults are gray to brownish black. Larvae are c-shaped, legless, and creamy colored with brownish heads. Larvae feed in early spring and emerge from pupae in late-May to June. Adults (all female) feed for 21-45 days before egg laying in July when each female oviposits about 200 eggs in the soil or leaf litter around the plant. Adult feeding appears as notches on leaves. Larvae prefer to feed on young roots, but scarce roots and moist soil results in stem feeding that can eventually girdle plants. Larvae feed until soil temperatures force them to dig deeper to overwinter.

Black vine weevil adult. Photo by Mike Reding & Betsy Anderson, USDA Agricultural Research Service, Bugwood.org

Adult black vine weevil feeding appears as notches on leaves. Photo by Eric R. Day, Virginia Polytechnic Institute and State University, Bugwood.org

Black vine weevil larvae. Photo by Mike Reding & Betsy Anderson, USDA Agricultural Research Service, Bugwood.org

Information from Brian Kunkel, Ornamental IPM Specialist, UD

Landscape - Insects and Swimming Pools

Clients may complain to you about insects in swimming pools. The following is some information that you can pass on to them.

Swimming pools attract a variety of insects. Honey bees come to collect water for use in their colonies. A few aquatic insects, mostly bugs and beetles, come because water is their natural environment; to them, a swimming pool is just another pond. A few (like thrips) come as a result of disturbances – cutting hay fields or wheat. Finally, there are those that just accidentally fall into the water and cannot escape.

Honey bees need lots of water to maintain optimum hive temperature and humidity; a nearby swimming pool may be the most convenient supply, causing alarm to pool owners and users. Worker bees that find a good water source will recruit colony mates to join them. Over time, hundreds of bees may be appear. Some will fall into the water and drown but others will keep coming. They are preoccupied with this task and generally are not a threat. Dealing with bee visits to small kiddy pools can be as simple as moving the pool to a different spot in the yard every few days. Bees follow directions very strictly and if the pool is not where it should be, they will not find it easily. You can stay ahead of them with the moves.

Aquatic insects, such as backswimmer bugs and toe biters, may arrive in large numbers as they fly from ponds in which they developed to colonize other bodies of standing water. In some cases, they may be abundant enough to clog filtering systems. Usually, this mass movement lasts only a few days. Backswimmers are predators; they can give a painful bite with their piercing-sucking mouthparts. There should be no question as to what the toe biter can do. The pain from these bites is similar to a bee sting but there is no toxin.

Thrips can make a dramatic appearance. These tiny elongate yellow insects were described on one insect ID form as follows: "These little biting things covered an aboveground pool and deck. They were so thick that you could wipe them off with your hand. They have painful bites, children could not play in the pool for them." Thrips show up at pools probably drawn to water or driven there from nearby recently-cut hay fields. On normal days thrips use their abrasive mouthparts to rasp at plant tissue, especially flowers. However, they will scrape skin, perhaps as they attempt to pick up small amounts of moisture. An occasional thrips scrape probably is tolerable but lots of them do not add to the swimming experience. A strong jet of water may be used to plaster them to decks and other surfaces where they have accumulated.

Finding and managing the source of an insect problem usually is the most effective management practice but this is rarely possible or practical with swimming pool invaders. There is no safe or effective means of treating pool water to keep intentional or accidental invaders away. Covering the pool when it is not in use may be the best and only way to exclude chronic problems with unwanted creatures. Fortunately, this may be needed for only a few days at a time. The clumsy pool invaders are the easiest to handle – the few that fall in can be removed with a cleaning net or cup.

Reprinted from "Few Management Alternatives for Insects around Swimming Pools" By Lee Townsend in the current edition of the Kentucky Pest News http://www.uky.edu/Ag/kpn/kpn_09/pn_090707.html

Landscape, Nursery, and Turf - Provaunt Insecticide

The following is information on Provaunt insecticide, one of the new low risk materials that is on the market for use in landscape, nurseries, and turf.

Provaunt

Provaunt, containing the active ingredients Indoxacarb, is a low risk pesticide for use in landscape and turf areas. This is also another product from Dupont Company. It controls caterpillars such as gypsy moth, bagworms, webworms, and yellowneck caterpillars. This material is not systemic. If applied for caterpillar control it is suggested that it be applied to early life stages of caterpillars.

It also is labeled for control of potato leafhopper. For foliar applications the label rate is 1.25 – 2 oz/100 gallons of water.

In turf areas it controls several species of cutworms, armyworms, sodwebworms and grasshoppers. For turfgrass it is used at very low rates of 2- 4 ounces of product per acre.

Information from Stanton Gill, Extension Specialist, Central Maryland Research and Education Center, University of Maryland Cooperative Extension

Landscape and Turf - Spent Mushroom Soil

Spent mushroom soil is a readily available resource in Delaware as the mushroom industry is nearby. The following is information on the characteristics of spent mushroom soil.

Characteristics of SMS

Spent mushroom substrate is the composted organic material remaining after a crop of mushrooms is harvested. Mushrooms are grown in a mixture of natural products, including horse-bedded straw (straw from horse stables), hay, poultry manure, ground corn cobs, cottonseed hulls, gypsum, and other substances. This mixture is composted in piles or ricks, creating a dark brown, fibrous, and pliable organic growing media. When the composting process is complete, the media is brought into mushroom houses where it is placed into beds or trays and used as a substrate for growing mushrooms. After the mushrooms are harvested, the "spent" substrate is removed from the houses and pasteurized with steam to kill insects, pathogens, and mushroom remnants.

Spent mushroom substrate is sometimes sold immediately after it is removed from mushroom houses; in this case it is referred to as "fresh SMS". Alternatively, the SMS can be placed in windrows and further composted for several weeks or several months. This material is often called "weathered SMS" and differs in composition and appearance from fresh SMS. Some producers blend SMS with soil to produce a ready-to-use growing medium for turfgrasses and other plants.

Information from "USING SPENT MUSHROOM SUBSTRATE (MUSHROOM SOIL) AS A SOIL AMENDMENT TO IMPROVE TURF" from Penn State University.

Landscape and Nursery - Conserve Insecticide

The following is information on Conserve insecticide. This is one of the newer low risk insecticides for use in the landscape and nurseries.

Conserve

Conserve SC, spinosad, is a very safe insecticide from Dow Agro Science that has been in the marketplace for several years. It is a low risk pesticide that is made through fermentation of naturally occurring fungi. It is very effective in controlling lepidopterous caterpillars, several sawfly species larvae, thrips and some leafminers. In turfgrass it can be used to control cutworms, armyworms and sodwebworms. It is labeled for use in the landscape, nursery and turfgrass areas. In nurseries it has a 4 hour REI.

This material is very gentle to beneficial organisms such as ladybird beetles, lacewings and other predators. This product has no detectable ill impact on birds or fish.

For caterpillar control such as bagworms, tent caterpillars and other leaf feeder it works well on young larvae and later instar larvae.

Information from Stanton Gill, Extension Specialist, Central Maryland Research and Education Center, University of Maryland Cooperative Extension

Landscape - Nuisance Fungi and Landscape Mulch

The following is information on different nuisance fungi that sometimes grow in landscape mulch.

Mulches are used in Delaware gardens and landscapes for many reasons. By suppressing vegetation near trees and shrubs, they keep mowers and string trimmers from damaging the bark. In landscape beds and in the garden, they control weeds, improve drainage, prevent soil water loss, lower soil temperatures, prevent soil erosion and, as they decompose they release minerals and leave behind humus which benefits the plants. Organic mulches generally suppress plant pathogenic fungi and enhance beneficial mycorrhizal fungi. For continuing benefits, mulches need to be reapplied periodically. However, mulches are sometimes misused, especially around trees where excessive mulch (volcano mulch) is placed against the trunk, a practice which is harmful to trees.

Earlier in June, rains and use of fresh wood chip or bark mulch in landscape beds resulted in a proliferation of nuisance fungi growing in or on the mulch. One that was prevalent is slime mold (sometimes referred to as “dog vomit fungus”) which produces yellow or whitish patches of mold which later turn gray as they dry out. This slime mold spreads over the surface of the landscape mulch, sometimes surrounding the stems of plants in the bed. Although nuisance fungi such as slime mold rarely harm plants, some homeowners and landscapers object to their appearance and thus seek ways to prevent or eliminate these fungi.

There are many examples of fungi that grow on or from landscape mulch. Examples include stinkhorns (Mutinus and other related species), bird’s nest fungus (Crucibularium), earth stars (Geastrum spp), assorted toadstools, slime molds (Physarum and other species), and the shotgun, or artillery fungus (Sphaerobolus). Of these, only the shotgun fungus is truly a nuisance because it shoots tiny black spore masses onto nearby surfaces such as home siding and cars. Fungi also permeate thick layers of dry mulch, creating a hydrophobic mulch which is not easily penetrated by water, thus causing irrigation problems. Fertility problems can result when the fungi decomposing mulch removes nitrogen from the soil which is needed by the plants.

With proper manipulation, mulches can be prevented from developing nuisance fungi while maintaining the benefits of mulch. Much work on microbes and mulch has been done at Ohio State University where they have found that hardwood mulches (commonly used in Kentucky), especially if finely ground, contain a large amount of cellulose which decomposes fairly rapidly and leads to nuisance fungi. Such mulches, if composted for a few weeks with added nitrogen, and maintained at moisture levels over 40%, will not develop nuisance fungi. Such moisture levels allow bacteria and other fungi to compete with the nuisance molds. Wet mulches are heavy and require more effort to transport; however, moisture contents of organic products up to 50% will not present excessive transport weight problems.

The following are suggestions for the landscape industry and for homeowners wishing to avoid nuisance fungi:
-Purchase composted mulch products.
-Use mulches low in wood and high in bark.
-Avoid finely ground woody products unless composted first.
I-f using fresh wood chips such as those from a tree maintenance firm, add water to the mulch and allow the pile to partially compost for six weeks. If the wood chips do not include fresh leaves, add some nitrogen to speed composting.
-Use coarse mulches, but do not apply them too deep.
-Soak all mulches with water immediately after application to enhance bacterial colonization.
-Do not apply mulch deeper than three inches.
-Do not use sour mulches (highly acidic mulches giving off an acrid odor) because they injure plants.

Reprinted with slight edits for DE from "Mulches, Mushrooms and Molds" By John Hartman in the current edition of the Kentucky Pest News http://www.uky.edu/Ag/kpn/kpn_09/pn_090707.html

Landscape and Nursery - Bt for Caterpillar Control

The following is information on the use of Bt biological insecticide for caterpillar control in ornamental plants.

Bacillus thuringiensis (Bt)

Bt is one of the oldest and very safe materials used for control of caterpillars. The insecticide produced from this rod-shaped bacterium does not harm animals, birds, beneficial insects or humans. This material is not systemic and must be ingested by a caterpillar to cause death. When eaten by a caterpillar a crystal dissolves in the insect’s stomach and breaks down the stomach wall. The crystal can only dissolve in those insects species whose stomach contain the correct combination of pH, salts, and enzymes. It cannot dissolve the highly acidic stomach of humans. Because of the selectivity, the US EPA permits food crops sprayed with Bt to be eaten right after spraying. Bt is effective in controlling early stages of caterpillars but is rather ineffective against late instar stages of caterpillars. It can provide good control of early instars of bagworms, eastern tent caterpillars, fall webworms, yellowneck caterpillars, orange stripped oak caterpillar and several other lepidopterous species of caterpillars. Note: Bt will not control sawfly caterpillars which are in the order Hymentoptera.

Information from Stanton Gill, Extension Specialist, Central Maryland Research and Education Center, University of Maryland Cooperative Extension

Landscape - Flatheaded Appletree Borer

The following is information on the Flatheaded Appletree Borer, a pest of many tree species in Delaware

Flatheaded Appletree Borer, Chrysobothris femorata

Flatheaded apple tree borer adults are dark greenish brown on top (dorsal) and brown on the underside (ventral). The wings have two wavy, indented light bands. Look for the adults in sunny locations. You may find adults in the early morning sitting on the bark of a tree. The adults tend to attack stressed apple, beech, dogwood, elm, linden, oak, willows and apple trees. The last two years of drought has stressed many trees in Delaware making them susceptible to attack from this borer. Young, newly transplanted trees can be attacked and killed by this beetle.

Non-chemical Control: Keep trees healthy and vigorous and this beetle will not be a problem. It is easy to say and hard to do in a lot of situations.

Chemical Control: Apply Onyx or Astro to the main trunk of the tree.

Photo of flatheaded apple tree borer by Joseph Berger, Bugwood.org

Information adapted from the current edition of the TPM/IPM Weekly Report for Arborists, Landscape Managers & Nursery Managers from the University of Maryland Cooperative Extension.

Landscape and Nursery - Downy Mildew on Rudbeckia

Rudbeckia, especially the cultivar "Goldsturm" has been showing susceptiblity to a number of diseases in recent years. The following is information on Downy Mildew of Rudbeckia.

Downy mildew is becoming an increasingly important problem in nurseries. The disease is caused by the fungus Plasmopara halstedii. A recent report detailed a severe outbreak of downy mildew on Rudbeckia ‘Goldsturm’ in Virginia Beach nurseries in June 2005 and 2006, when most of the crop was lost, though other Rudbeckia species and cultivars adjacent to Goldsturm were not affected.

The symptoms begin as light green spots on leaves’ upper surfaces. These mature into dark necrotic blotches, with fuzzy gray-white hyphae and spores appearing on the lower surfaces. Leaf and shoot distortions may follow. In warmer areas, the fungus can overwinter as oospores in dead plant material or soil. If it is not warm enough for inoculum to survive in infected plant debris or soil, spores will arrive by wind or through introduction of infected plant material from southern areas. New infections begin as water splashes spores to the surfaces of lower leaves. Additional spores produced in these leaves will travel by wind or water to spread the disease. Favorable temperatures for disease development are cool – 58 to 72 °F – with humidity higher than 85% at the leaf surface.

Management: Growers should scout incoming plant material carefully for signs of downy mildew. Infected plants must be removed and destroyed immediately – do not compost these. Keep nighttime temperatures in greenhouses high, and try to maintain humidity lower than 85% by proper spacing and pruning. Avoid overhead watering; keep leaves as dry as possible in the morning and early afternoon as this is when spore release and dissemination are most active. Fungicides should be used preventively. Downy mildews can develop resistance, so a combination of systemic and protectant fungicides will provide best control and avoid development of resistance. A partial listing of fungicides includes Subdue, Heritage, Phyton 27, Kocide, Dithane, and liquid copper. Professional applicators may be required.

Information from the current edition of the TPM/IPM Weekly Report for Arborists, Landscape Managers & Nursery Managers from the University of Maryland Cooperative Extension.

Landscape, Nursery, and Turf - Acelepyrn Insecticide

The following is information on Acelepyrn insecticide, a new, reduced risk insecticide for use in landscape, nurseries, and turf.

Acelepyrn from Dupont Company is very safe, new systemic material for controlling foliar feeding caterpillars, some boring caterpillars, lacebugs and some leafminers in the landscape. Acelepryn uses an entirely unique class of chemistry with a novel mode of action and active ingredient that has been classified as EPA Reduced Risk for turf applications. Acelepryn also has a low impact on non-target organisms such as beneficial arthropods as well as bees, birds, fish and mammals, and has a very low water solubility. It is the first insecticide in the new anthranilic diamide class of chemistry.

Acelepryn has been developed to provide control of caterpillars feeding on trees and shrubs. It has been reported to kill fairly late instar caterpillar stages. This material can be used for caterpillars that feed in turfgrass such as sod webworm and armyworm. It also does an excellent job of controlling white grubs, bluegrass weevil, and billbugs. For white grubs, the labels states it is applied in April through September. One application provides season long control. For billbug control, apply the material in April or May when billbugs are first observed. For tree and shrub applications it can be used as a foliar, soil or bark treatment for ornamental insect control. Since it is a systemic it will be taken up from a soil application, but it should be applied within 1 - 3 ft of the base of the plant. For foliar applications for controlling caterpillars such as bagworms the label range is 1 - 2 oz mixed in 100 gallons of water. For maximum residual control the labels states to use it at a rate of 16 oz/100 gallons of water. This would be one expensive treatment at this high rate.

Lepidoptera (caterpillars) boring into trees: Acelepryn can be applied to the trunk of trees for control of clearwing moth borer larvae such as banded ash clearwing and peachtree borer. The label states that the product should be used at 4 oz/100 gallons of water and sprayed on the trunk down to the flair of the plant. Apply the material after adult emergence.

Acelepryn contains the new active ingredient chlorantranilirole. It is used at very low application rates (0.1 lb/acre A.I.). Here is the best part: DuPont Acelepryn has been classified as a reduced risk insecticide by the EPA. It has also received the presidential green seal award.

Information from "Being Greener When Controlling Bugs" By Stanton Gill, Extension Specialist, Central Maryland Research and Education Center, University of Maryland Cooperative Extension and Professor in Landscape Technology,Montgomery College, sgill@umd.edu, www.ipmnet.umd.edu.

Landscape - Mulch and Termites

The following is a good article on mulch and termites from the University of Maryland.

Like daffodils and dogwoods, fresh mulch is a harbinger of Spring. Whether it's traditional favorites like shredded hardwood and pine bark or specialty products like pine straw and cedar bark, gardeners and landscapers depend on organic mulches to conserve water, reduce weeds, and give gardens a tidy, orderly appearance. Subterranean termites are notorious for tunneling into wood items that are in direct contact with the soil, such as planters, fences, and trellises, and gaining access to homes via these exterior fixtures. Homeowners, mindful of this well-earned reputation, often question whether wood and bark mulches can attract and support foraging termites.

Field research at the University of Maryland, College Park, indicates that organic mulches do not attract termites to the underlying soil, nor will the termites consume mulches in any great quantity. Termites have been observed within newly purchased bags of moist mulch, as well as bags that had been allowed to sit undisturbed for a while. The warm, wet environment of these full bags is ideal for the termites, but such conditions do not exist when the mulch is applied to its recommended depth of 3-4 inches. However, foraging termites can travel within the mulch layer and could theoretically use the mulch as a bridge up over a termiticide treatment around a foundation and into a home. For this reason, it is recommended that a band of bare soil be left around foundations. Surprisingly, even pea gravel perimeters should be avoided. Termites have been shown to feed more actively at resources beneath inorganic gravel mulches, presumably because gravel and stone mulches create a cool, moist, “shadow” underground where the insects can take refuge during the heat of summer.

Reprinted from "Landscape Mulches and Subterranean Termites" by Catherine Long, Graduate Student, University of Maryland, College Park