for Arborists, Landscape Managers & Nursery Managers

Commercial Horticulture October 18, 2013Coordinator Weekly IPM Report: Stanton Gill, Extension Specialist, IPM for Nursery, Greenhouse and Managed Landscapes, sgill@umd.edu. 301-596-9413 (office) or 410-868-9400 (cell)

Regular Contributors: Pest and Beneficial Insect Information: Stanton Gill and Paula Shrewsbury (Extension Specialists) Disease Information: Karen Rane (Plant Pathologist) and David Clement (Extension Specialist)Weed of the Week: Chuck Schuster (Extension Educator, Montgomery County)Cultural Information: Ginny Rosenkranz (Extension Educator, Wicomico/Worcester/Somerset Counties)Fertility Management: Andrew Ristvey (Regional Specialist, Wye Research & Education Center)Design, Layout and Editing: Suzanne Klick (Technician, CMREC)

In This Issue...

If you work for a commercial horticultural business in the area, you can report insect, disease, weed or cultural

plant problems found in the landscape or nursery to

sklick@umd.edu

TPM/IPM Weekly Report

- Brown marmorated stink bugs- Weather update - rain- Turfgrass field day- Scale (and predators) on magnolia- Lawn fertilizer law sessions- Citrus mites- Groundhogs- Deer repellants- Damage on arborvitae- White pine aphids- Weed control in turf- Puffballs in turf- Boxwood mite- EAB webinars

Weed of the WeekPlant of the WeekDegree DaysAnnouncements

IPMnet

Integrated Pest Management for

Commercial Horticulture

extension.umd.edu/ipm

Brown Marmorated Stink BugsTwo weeks ago when we had the bout of warm weather we saw hyper-activity of adult stink bugs accumulating on the sides of building. The extended rain period this last week suppressed the activity and we have had very few reports of stink bug activity for the last 7 days. They have not gone away, but are laying low in the wet and cool weather.

University of Maryland Fall Turfgrass Field Day

The Turfgrass Field Day will be on October 23rd at the Paint Branch Turfgrass Research Farm.

R.S.V.P. by October 16th to Tom Turner at tturner@umd.edu.

It is $15 for people who are not members of the Maryland Turfgrass Council and attending lunch which starts at 11AM. If you are not having lunch and just wish to attend the tour, there is no charge and the tour starts at 11:45AM. Members of the Maryland Turfgrass Council are free of charge.

Rain TotalsWe received some much needed rain over the last week. Marsha Williard, Mar-Lu View Nursery, reported fall totals in Hagerstown (4.5”) and Jefferson (a little over 5”). Five day totals for the airports ending October 14 areBWI = 6.59”, Dulles = 6.26”, and Reagan National = 4.99”

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Predaceous caterpillar, Laetilia coccidivora, that feeds on scale insects (left) and a syrphid fly larva that was found underneath a tuliptree scale cover (right)

Several Scale on MagnoliaWe looked at samples this week of deciduous magnolia from Laytonsville that had three species of scale on them. Crawlers and immatures of tuliptree scale and magnolia scale were present. Magnolia scale is only found on magnolia, but tuliptree scale can be found on magnolia, tuliptree, and sometimes on linden, hickory, basswood, walnut, and buttonbush. These scales are finishing up their crawler stage and both will overwinter as black immatures. There were also just a few Indian wax scale on the samples. Its crawler stage was back in mid June.

Looking under the covers of the tuliptree scale, we found six predaceous caterpillars, Laetilia coccidivora, Under one cover was a syrphid fly larva. Oil treatements of the tuliptree scale started two weeks ago with oil so there was some control, but since hatching is still occurring, it is necessary to retreat if using oil or use a longer term treatment like Distance or Talus. Oil treatments have less of an impact on beneficials.

Female covers of tuliptree scale (left) and female cover and immatures of magnolia scale (right)

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Citrus MitesFor the last couple of years many garden centers have been selling orange, lemon, and lime trees from California and Florida nurseries. Many of your customers are growing these citrus trees in pots on their decks and patios and moving them indoors in fall. As we move toward cooler weather your customers will be moving these trees into sunny windows in their houses. Two of the common pests on these trees are citrus rust mite, Phyllocoptruta oleivora, and citrus red mite, Panonychus citri. Both these mites damage epidermal cells of plant leaves, fruit, and green twigs of all citrus varieties using piercing-sucking mouthparts. The citrus rust mites is elongated and wedge-shaped, approximately three times longer than wide. Magnification is required to see it as the adult is extremely small, and the immature stages are slightly smaller. Color ranges from light yellow to straw brown. The citrus red mite is deep red to reddish purple in color. The female is oval and about 0.5 mm long and has white setae arising from the dorsal body surface. The adult male has long legs, a tapering abdomen and is smaller than the female. Both of these mites are often present on the plants and when your customers move the plants indoors and turn on their heating systems, which will happen as the weather gets colder, the mites flourish in the dry, hot conditions.Control: To knock down the population of these two mites a 1 - 2% horticultural oil can be applied to the foliage and stems while the plants are still out on the deck or patio. This application will help reduce the amount of damage during the fall and winter.

Lawn Fertilizer Law Information on Maryland’s Lawn Fertilizer Lawn including review sessions and testing dates and a pdf version of The Professional Lawn Care Manual are available at: http://mda.maryland.gov/fertilizer.

Test DATES and LOCATIONSSalisbury Carroll Community CollegeOctober 23, 2013 December 11, 2013 (also covers CEUs if you have already passedWicomico County Extension Office the test)28647 Old Quantico RoadSalisbury, MD 21801

Citrus red mitePhoto: Jim Baker, North Carolina State University, Bugwood.org

Damage from citrus rust mitePhoto: Don Ferrin, Louisiana State University Agricultural Center, Bugwood.org

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Deer RepellantsSteve Sullivan, The Brickman Group, reported really great success using Deer Scram as a repellant for deer. It comes in a bucket and is a granular, made from dried blood, dried deer meat, cloves, onions and garlic. Reapply every 4-6 weeks. Someone from Leisure World commented about using Irish Spring soap as a repellant.

Possible Japanese Cedar Longhorned Borer (also bark beetles)Damian Varga, Scientific Plant Service, brought in an arborvitae sample from Baltimore County with tunnelling under the bark and dieback. We could not locate an adult or larvae, but it looks like the damage could be from JCLB as well as bark beetles. The plants have been established for 5 years.

GroundhogsWe had an inquiry come in via email asking about groundhog damage in nurseries. It brings up an interesting topic on pest control. The reason for the animosity between some nursery managers and groundhogs can be traced to the fact that groundhogs are pretty good at taking advantage of areas plowed or loosened by nursery practices. As a consequence, they tend to start new burrows anywhere a nursery manager has already disturbed the ground. This means that groundhogs see new nursery trees as construction opportunities -- places where new burrows can be dug quickly and with a minimum of effort.

The average groundhog excavates over 700 pounds of dirt digging just one den, and a single groundhog may have four or five dens scattered across its territory, moving in and out of them as crops and weather change. The really interesting thing if they are removing 700 lb of soil where do they put it all? The mound outside their opening is really not extremely high, in most cases.

It is hard to think of groundhogs as beneficial, but keep in mind that groundhog burrows are important shelter resources for red fox, gray fox, opossum, raccoon, and skunk, most of whom do not dig their own burrows, but simply occupy those of groundhogs. That said, most nursery managers try to control groundhogs in the nursery row. If you have an interesting and legal method of taking out groundhogs that you are willing to share we would love to hear about your “best methods”. I will write these up for the next week IPM report. Send them to sgill@umd.edu.

White Pine AphidsWhite pine aphids, one of the larger aphids found in the landscape, are active this week on white pines. Sam Fisher, Woodacres Tree Specialists, reports a lot of activity from ladybird larvae feeding on these aphids. These aphids are big and have white and black markings on the body. They are active in September and October and feed on the trunk and branches. The aphid usually does not cause major dieback of the pine but they excrete copiousamounts of honeydew that covers needles and sooty mold grows on the honeydew. By October your customers may have needles covered with black sooty mold. Control: In most cases it is not necessary, but if you need a low risk material, use horticultural oil, insecticidal soap, or Azadirachtin (Neem) products.

White pine aphidPhoto: William H. Hoffard, USDA Forest Service, Bugwood.org

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Weed Control in TurfWe recently reported about using iron applications to control weeds in turf using Fiesta (active ingredient is Iron HEDTA) applications made at the University of Maryland turf plots three weeks ago and it looks like iron makes it goes off color. On clover and dandelion it seems to burn it back. Kevin Mathias, Institute of Applied Agriculture, suspects when applied in the fall, it should kill the clover, but in spring it only burns it a bit and then it comes back.

Details on this trial will be presented at the October 23rd turf field day. Field day information is on page one of this report.

Boxwood MiteCraig Greco, Yardbirds, Inc., sent in a photo of boxwood with heavy boxwood mite damage. Feeding by these mites causes yellow stippling damage on foliage. A dormant horticultural oil spray will control eggs on the undersides of leaves. A residual miticide may be necessary if populations are very high.

Puffballs in TurfWith drenching rains last week we are receiving reports of lawns with puffballs croppping up now. They grow on decaying organic matter and are most likely to form on tree stumps, tree roots, or other spots in the lawn with high organic debris. They can be hard to eradicate because it takes years for them to use up their food source in the turf.

The turf block treated with Fiesta is the one that has a reddish tinge to it

Puffball fruiting bodiesPhoto: Gerald Holmes, Valent USA Corporation, Bugwood.org

Mite damage on boxwoodPhoto: Craig Greco, Yardbirds, Inc.

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Common cockleburPhoto: Robert Vidéki, Doronicum Kft., Bugwood.org

Upcoming Webinars - Emerald Ash BorerWebinars on emerald ash borer are being conduced at emeraldashborer.info this fall. Go to http://www.emeraldashborer.info/eab_university.cfm to view the webinars. The scheduled is listed below. The first two have already been conducted and are archived on-line.

Invasions by Non-native Insect Pests and Arboriculture (posted on-line)Mike Raupp, University of MarylandThursday, September 26, 2013 at 11am ET

EAB Biocontrol Progress and Possibliities (posted on-line)Juli Gould, USDA APHIS Thursday, October 10, 2013 at 11am ET

US Regulatory Measures to Control Invasives and Limit Introductions using the Case Study of ALB in MassachusettsClint McFarland, USDA APHIS Federal Project Manager, Asian Longhorned Beetle Eradication Program-Massachusetts Thursday, October 24, 2013 at 11am ET

Building an EAB management program from the ground up: Milwaukee’s perspectiveRandy Krouse, City of Milwaukee Thursday, November 7, 2013 at 11am ET

Economic impact and management of EAB in woodlots, classic wood utilizationEric McConnell, The Ohio State University Thursday, December 5, 2013 at 11am ET

Common cockleburPhoto: Jan Samanek, State Phytosanitary Administration, Bugwood.org

Weed of the Week, Chuck SchusterCommon cocklebur, Xanthium strumarium, is a summer annual dicot weed. This annual is easy to identify as it produces a prickly cocklebur and grows from six inches to six and one half feet in height. Found commonly in many settings, it is one that will often be found in nurseries and occasionally in landscapes. Common cocklebur has a taproot. The first true leaves are opposite, and all leaves above this point are alternate. Leaves are triangular in shape and have stiff hairs. The leaves may be two to six inches in length, with three very prominent veins on the upper surface arising from the same point. Common cocklebur may be mistaken for giant ragweed in early stages; however the cotyledons of common cocklebur are much longer and more linear than those of giant ragweed.

Control of common cocklebur can be obtained by using post emergent non selective herbicides such as glyphosate. Some resistance is being found with pre emergent herbicides. In turf settings it can be controlled with 2, 4D products.

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Plant of the Week, Ginny RosenkranzSolidago sphacelata ‘Golden Fleece’ was introduced from Mt. Cuba Gardens in Delaware. ‘Golden Fleece’ thrives in full sun areas, adding bright golden yellow color to late summer and fall gardens. The soil pH for ‘Golden Fleece’ can be average to alkaline while the soil moisture can be moist, well drained or even very dry. ‘Golden Fleece’ grows in USDA zones 4-9 and can tolerate clay soils, rocky soils, sandy or sandy loam soils. Unlike the native goldenrod, ‘Golden Fleece’ is more compact in growth habit, growing only 15-24 inches tall and wide, but can quickly spread to become a fairly dense low growing mat forming groundcover. The semi-evergreen heart shaped foliage grows in a rosette until late summer when arching stems with alternate leaves rise up to display the bright golden yellow flowers arranged in a dense pattern on top. ‘Golden Fleece’ flowers last for 4-6 weeks and attract hummingbirds, bees and many butterflies like the hairstreaks, sulphurs, skippers, viceroys, painted ladies and monarchs, but does not attract deer. Plants can be displayed in containers, in perennial gardens, as a groundcover or as a naturalized planting. Plants should be divided every 3-5 years to keep them healthy. Rust on the foliage can be problematic.

Solidago sphacelata ‘Golden Fleece’Photo: Ginny Rosenkranz, UME

Degree Days (As of October 17)Baltimore, MD (BWI) 3822 Dulles Airport 3797 Frostburg, MD 2349 Martinsburg, WV 3488 National Arboretum 4397 Reagan National 4397Salisbury 4216

To check degree day (DD) accumulations in your local area go to: http://www.weather.com/outdoors/agriculture/growing-degree-days/USMD0100

Note: degree days reported in this newsletter for various pests use the Weather.com web site, a base temperature of 50 °F, a start date of January 1st, and the date of monitoring as the end date.

Upcoming ProgramsListing includes registration information for the December 11th nutrient management program and the December 12th pest management program. Both will be held at Carroll Community College.

Go to https://www.extension.umd.edu/ipm/conferences

Stanton GillExtension Specialist

sgill@umd.edu

Paula Shrewsbury Extension Specialistpshrewsb@umd.edu

Ginny RosenkranzExtension Educatorrosnkrnz@umd.edu

Chuck SchusterExtension Educator

cfs@umd.edu

Karen Rane Plant Pathologistrane@umd.edu

Andrew RistveyExtension Specialistaristvey@umd.edu

David ClementPlant Pathologist

hgic.umd.edu

The information given herein is supplied with the understanding that no discrimination is intended and no endorsement by University of Maryland Extension is implied.

CONTRIBUTORS:

University of Maryland Extension programs are open to all citizens without regard to race, color, gender, disability, religion, age, sexual orientation, marital or parental status, or national origin.

Thank you to the Maryland Arborist Association, the Landscape Contractors Association of MD, D.C. and VA, the Maryland Nursery and Landscape Association, Professional Grounds Management Society, and FALCAN for your

financial support in making these weekly reports possible.

Photos are by Suzanne Klick or Stanton Gill unless stated otherwise.

Trees Matter SymposiumNovember 20, 2013Location: Silver Spring Civic BuildingContact: Holly Thomas, 301-650-2611http://www.montgomeryparks.org/brookside/documents/treesmatter2013.pdf

Maryland Lawn Fertilizer Law Review, CEUs and Test December 11, 2013Location: Carroll Community College, Westminster, MDhttp://extension.umd.edu/ipm/conferences

Pest Management ConferenceDecember 12, 2013Location: Carroll Community College, Westminster, MDhttp://extension.umd.edu/ipm/conferences

2014 Maryland Turfgrass Conference & TradshowJanuary 6-7, 2014Annual Conference and TradeshowLocation: STAMP Student Union, University of Maryland, College Park, MarylandContact: Michelle LoConte, mdturfcouncil@verizon.net Vendor Contact: Bill Warpinski, billw@centralsod.com

USDA Research Forum on Invasive SpeciesJanuary 7 – 10, 2014Location: Loew’s Hotel, Annapolis, MDContact: Michael McManus, mlmcmanus@fs.fed.us

MANTS – Nursery Trade ShowJanuary 8 – 10, 2014Location: Baltimore Convention Center

MAA Winter ConferenceJanuary 15 and 16, 2014Location: Turf Valley, Ellicott City, MDContact: 410-321-8082

Advanced Landscape Plant IPM PHC Short Course January 21-24, 2014Location: UMD, College Park, MDContact: Avis Koeiman, akoeiman@umd.edu, 301-405-3913

PGMS Green Industry Recertification SeminarJanuary 22, 2014Location: Northern Virginia Community College AnnandaleContact: Mary Bean, mbeanhouse@aol.com, 202-215-1134

FALCAN ConferenceJanuary 29, 2014Location: Frederick County Fairgrounds, Frederick, MDContact: Dan Felice, 301-606-8631dfelice@synateksolutions.com

Eastern Shore Pest Management ConferenceFebruary 5, 2014Location: The Fountains, Salisbury, MDContact: Ginny Rosenkranz, 410-749-6141

LCA Winter ConferenceFebruary 12, 2014Location: UMD, Shady Grove CampusContact: 301-948-0810

2014 Chesapeake Green: A Horticulture SymposiumFebruary 20 and 21, 2014Location: Maritime Institute, Linthicum Heights, MD