for Arborists, Landscape Managers & Nursery Managers

Commercial Horticulture October 3, 2014Coordinator 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) and Nancy Harding, Faculty Research AssistantDisease 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

- Banded ash clearwing borer- AGNR Open House- Brown marmorated stink bugs- Scale update- Skiff moth caterpillar- Japanese beetles

Beneficial of the WeekWeed of the WeekDegree DaysAnnouncements

IPMnetIntegrated Pest Management for

Commercial Horticulture

extension.umd.edu/ipm

Empty pupal case on trunk (left) and a newly emerged adult near exit hole (above)

Banded Ash Clearwing BorersBy: Stanton GillFor the last 2 weeks we have been pulling in banded ash clearwing adult males in pheromone traps in Westminster. This weekend the trap counts dropped to zero so I would say flight activity is likely to be finished for the season. The female, after mating with the males, usually have about two weeks until the egg laying occurs. If you are trying to protect white or green ash from banded ash clearwing borers just about now would be the time to apply permethrin (Astro) or bifenthrin (Onyx) to the trunks of susceptible trees. If you are treating ash for emerald ash borer (EAB) with TriAge (Emamectin benzoate) it should control the banded ash clearwing for at least one year. It will control damage from EAB for at least two years.

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College of Agriculture and Natural Resources Open HouseOctober 11, 2014 (10 a.m. to 3 p.m.)

Location: Central Maryland Research and Education Center - Clarksville Facility4240 Folly Quarter Road, Ellicott City, MD 21042

Find out more at http://agnr.umd.edu/openhouse

Come to our Open House at the farm and learn how our Academic, Research, and Extension programs benefit you. See the horses, cows, calves, and turtles . . . participate in birdwatching . . .see the beautiful butterflies . . .watch chicks hatch out of their eggs . . . check out the backyard poultry . . . take a hay wagon farm tour . . . visit the educational and interactive displays and exhibits on everything from nutrition to rural enterprise development. . . participate in the numerous hands-on activities . . . purchase some food from one of the student organization food tents . . . talk with an AGNR representative . . . and get your plant questions answered by a Master Gardener

Tis the season...for BMSB to try and get into houses, offices, and sheds

Brown Marmorated Stink Bugs are Back By: Stanton GillOn Saturday, September 27, while working in my orchard, I noticed some adult brown marmorated stink bugs feeding on some of my late maturing Asian pear varieties. There were not many, just 3 or 4 adults, at most, on over 350 trees. When I broke for lunch I noticed adult BMSB on my farmhouse exterior walls, in my barn and on a light colored car. The interesting thing is that we have been monitoring for them all season long in the orchard using pheromone traps and never had more than a couple show up at any one time during the season. Suddenly, they showed up this weekend. I called Jerry Faulring, Waverly Farm, to see if there was any activity in Frederick. He said he was seeing adults on Friday and Saturday in their office and around his house. They were not in huge numbers like we saw three years ago, but the adults are back and hanging out on the sides of buildings. Brian Scheck, Maxalea, Inc., also reported that stink bugs were out in huge numbers in Timonium on Saturday, September 27.

Ed Rhone, Rhone’s Plants&Scapes, Chambersburg, PA, reports that it had been a quiet fall in 2013 and spring of 2014 regarding BMSB, but there has been a massive explosion in the farmlands around central Franklin County, PA last week. Ed noted that about 70% of the corn is harvested and after the cool rainy day on September 25 followed by a period of above average temperatures, high numbers of bugs have literally come out of the woods and fields this week.

With the bright sunny days and cool nights the adults BMSB are scouting out sites to overwinter. If you see large numbers hanging out in your area, please send me an email at sgill@umd.edu or call me at 410-868-9400. We are trying to keep track of where potential outbreak sites might occur. Thanks.

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Scale Update*By: Nancy Harding and Stanton Gill

White Prunicola Scale (WPS), Pseudaulacaspis prunicola (armored scale)Over the past couple of weeks we have reported 3rd generation WPS CRAWLER activity found on Prunus subhirtella ‘Autumnalis’ in Laytonsville. Therefore, this suggests crawler emergence can extend over a period of time, making management challenging. On Tuesday, September 30th our continued monitoring found WPS CRAWLERS still active but the percentage of crawlers dropped along with the number of females with eggs. There was however, an increase in the number of settled crawlers (1st instars) and 2nd instars indicating there is little more time for control measures to be implemented. The Degree Day accumulations in Laytonsville as of September 30th were 3430. If the degree day accumulations in your area are near 3430 DD you should monitor plants infested with WPS for crawler activity and if active there is still time to treat. We would predict after this week control measures will be less effective as crawler activity will likely decline.Monitoring: Examine Prunus species (especially Japanese flowering cherry), privet and lilac for signs of WPS scales (ex. white covers on bark). Note that white peach scale looks very similar to white prunicola scale. You should closely monitor for WPS crawler activity on host plants.Control: When WPS crawlers are active, apply pyriproxyfen (Distance) or buprofezin (Talus) mixed with 0.5 – 1% horticulture oil. If there are abundant live scales or scale covers on your trees, and it is feasible, you can use a soft brush with water to “scrub” the scales of the branches.

Skiff Moth Caterpillar Marty Adams, Bartlett Tree Experts, found a caterpillar that looks a lot like a leaf. It even has brown markings that resemble necrotic areas on a leaf. It is the skiff moth caterpillar which can be found feeding on variouswoody plants including birch, cherry, hawthorn, maple, rose, oak, poplar and willow. This caterpillar is often found on the upper sides of leaves. If you see an unpaired white marking on the caterpillar, it is the egg of a parasitic fly.Control: Not necessary.

A view of the underside of a skiff moth caterpillarPhoto: Marty Adams,

A view of the topside of a skiff moth caterpillar

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Japanese BeetlesEd Rhone, Rhone’s Plants&Scapes, Chambersburg, PA, reported on scarab beetle populations. He noted that like last year, untreated yard areas have been hammered by scarab beetles. Ed is also reporting that he has seen more Japanese aAdults on roses than ever from Labor Day to September 20 which is quite late in teh season for adult beetle activity.

Beneficial of the WeekBy: Paula ShrewsburyVelvet ants – Are they really ants?Although they look like beautiful hairy ants, velvet ants are not ants! They are actually wasps in the family Mutillidae (order: Hymenoptera) whose adult females are wingless and greatly resemble ants which are also in the order Hymenoptera. There are more than 3,000 species of velvet ants, most of them are brightly colored red and black or orange and black, though there are species that are white and black. The bright coloration of velvet ants, and other insects that are brightly colored in black with orange, red, or yellow, is referred to as aposematic or warning coloration. Predators have “learned” that bright colors are associated with bad tasting or toxic insects so they avoid attacking insects with aposematic coloration. Velvet ants are commonly found in habitats that are relatively dry with sandy soils. They are often active as adults July through September. When observing a velvet ant, remember only females of velvet ants, and Hymenoptera in general, can sting. The stinger in Hymenoptera is a modified ovipositor, which only females have. I have been asked how you can tell the difference between male and female velvet ants. I reply “if you pick one up and get stung it is a female”. However, I do not recommend this method since the sting of a velvet ant is known to be extremely painful. Actually, male velvet ants have wings. Fortunately, velvet ants are not aggressive. The life cycle of this omnivorous insect is interesting. Adult velvet ants feed on nectar. After mating, the female sneaks into a nest of ground nesting bees and wasps. The female velvet ant proceeds to oviposit one of her eggs near each larva or pupa in the nest of its prey. The velvet ant egg hatches and the larva feed on the young and pupa in the nest that their mother had invaded. When coming across a velvet ant be sure to admire its beauty, but pay heed to its aposematic coloration.

A velvet ant which is actually a wingless female waspPhoto: Jerry A. Payne, USDA Agricultural Research Service, Bugwood.org

Adult velvet ant males have wingsPhoto: Johnny N. Dell, Bugwood.org

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Fleabane daisyPhotos: Chuck Schuster, UME

Weed of the Week, Chuck SchusterAnnual or daisy fleabane, Erigeron annuus, is most often an annual but can be biennial on some occasions. It is common throughout the southeastern United States. This plant is a member of the Aster family.

This weed can grow 12 to 24 inches in height. The leaves of this plant are long and narrow, much smaller than the basal leaves and will most often occur on short petioles. The leaves are toothed and slightly hairy. The flowers have white outer rays and a yellow center and are one half to three quarter of an inch in diameter. The flowers form in clusters with the outer most flowers opening first. The stems are solid and covered with small soft hairs.

This weed can be controlled in turf with the use of most post emergent broadleaf weed control products including 2,4D, dicamba, in landscape, post emergent non selective herbicides including glyphosate products are effective.

Degree Days (As of October 2)

2014 2013 2012 2014 2013 2012Baltimore, MD (BWI) 3450 3600 4133 Dulles Airport 3278 3580 3992Frostburg, MD 2187 2231 2553 Martinsburg, WV 3297 3297 3697 National Arboretum 4238 4133 4681 Reagan National 4238 4133 4681Salisbury 3816 3929 4271 St. Mary’s City 3604 3721 4346

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 use a

base temperature of 50 °F, a start date of January 1st, and the date of monitoring as the end date.

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.

Upcoming Conferences

Advanced Landscape Plant IPM PHC Short CourseJanuary 5-8, 2015For registration information contact:Avis KoeimanDepartment of Entomology4112 Plant Sciences BuildingUniversity of Maryland College Park, MD 20742Tel: 301-405-3913Email: akoeiman@umd.edu

The 2014 to 2015 Conference Listing is posted on-line.

Schedules and registration information will be added as it becomes available.