for Arborists, Landscape Managers & Nursery Managers

Commercial Horticulture October 2, 2015Coordinator 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 (Extension 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

- Unusual lady bird beetle- EPA proposed changes- Banded ash clearwing borer- Spiders- Wasps and bees- Woolly beech blight aphids- Walking sticks- White prunicola scale- Golden rain tree bug

Beneficial of the WeekWeed of the WeekPlant of the WeekPhenologyDegree DaysAnnouncements

IPMnetIntegrated Pest Management for

Commercial Horticulture

extension.umd.edu/ipm

Unusual Lady Bird BeetleBy: Stanton Gill, University of Maryland ExtensionI love it when we get in something out of the ordinary. Bernie Mihm, Fine Earth Landscape Company, sent in a photo of insect pupae on an oak tree this week. Andrew M. Sutherland, Ph.D, BCE of Univ of California Extension, identified these pupae for us. They are a fungus-eating lady bird beetle. Pupae are the mycophagous coccinellid Psyllobora vigintimaculata. The larvae and adults are obligate consumers of spores and hyphae of powdery mildew fungi. They feed on foliage, in this case oak leaves, that usually harbor a large infection of a powdery mildew species. The coccinellids may or may not have cleaned leaves up before they dropped. Adults will probably emerge in time to overwinter in small aggregations. This beetle is one of the interesting insects found in the landscape as we enter the fall.

This cluster of insects are the pupal stage of a lady bird beetle that feeds on powdery mildew fungiPhoto: Bernie Mihm, Fine Earth Landscape Co.

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Pupal cases of banded ash clearwing borers are still being found on tree trunks

Worker Protection Standard: Action Update - 09/28/2015From: Amy Brown, University of Maryland Extension

The U.S. Environmental Protection Agency (EPA) announced today increased protections for the nation’s two million agricultural workers and their families. Each year, thousands of potentially preventable pesticide exposure incidents are reported that lead to sick days, lost wages and medical bills but with changes to the Agricultural Worker Protection Standard the risk of injury or illness resulting from contact with pesticides on farms and in forests, nurseries and greenhouses can be reduced.The revisions to the Worker Protection Standard cover many different areas. The major revisions include:

* Annual mandatory training to inform farmworkers on the required protections. This increases the likelihood that protections will be followed. Currently, training is only once every 5 years. * Expanded training includes instructions to reduce take-home exposure from pesticides on work clothing and other safety topics. * First-time ever minimum age requirement: Children under 18 are prohibited from handling pesticides. * Expanded mandatory posting of no-entry signs for the most hazardous pesticides. The signs prohibit entry into pesticide-treated fields until residues decline to a safe level. * New no-entry application-exclusion zones up to 100 feet surrounding pesticide application equipment will protect workers and others from exposure to pesticide overspray. * Requirement to provide more than one way for farmworkers and their representatives to gain access to pesticide application information and safety data sheets - centrally-posted, or by requesting records. * Mandatory record-keeping to improve states’ ability to follow up on pesticide violations and enforce compliance. Records of application-specific pesticide information, as well as farmworker training, must be kept for two years. * Anti-retaliation provisions are comparable to Department of Labor’s (DOL). * Changes in personal protective equipment will be consistent with DOL’s standards for ensuring respirators are effective, including fit test, medical evaluation and training. * Specific amounts of water to be used for routine washing, emergency eye flushing and other decontamination, including eye wash systems for handlers at pesticide mixing/loading sites. * Continue the exemption for farm owners and their immediate families with an expanded definition of immediate family.

Learn more about the updates standard on EPA’s website at http://www2.epa.gov/pesticide-worker-safety/revisions-worker-protection-standard

Banded Ash Clearwing BorerWe are still finding pupal cases of banded ash clearwing borers projecting from green ash trees in the Mt. Airy area (Central Maryland) this week. The adults have been emerging throughout September. If you are going to make a protective spray to the trunk and main branches now is the time of year to make the application. Onyx (bifenthrin) or Astro (permethrin) can be applied to trunks and branches.

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Wasps and BeesBy: Stanton Gill, University of Maryland ExtensionThe number of flowering plants is rapidly declining in October and bees and wasps are becoming increasingly desperate for nectar sources. As a result, any fruit that is dropping beneath your customers’ fruit trees will attract the attention of bees and wasps. After last week’s IPM Alert we have had a couple of landscape managers call in to report that hornets and wasps are getting aggressive this fall. One nursery manager sent in a picture of a large hornet’s nest in one of the holly trees in his nursery. He was digging trees when he unfortunately found the low hanging nest. It did not end well for him, his workers or the hornets.

This argiope spider is easy to spot with its bright yellow markings

Woolly Beech Blight AphidsBy: Stanton Gill, University of Maryland ExtensionDiane Knighton, Design With Nature, found woolly beech blight aphids on American beech when doing a forest inventory. Last year, we received many reports of this aphid. The aphids look like dancing white fluff on a beech. This aphid raises the posterior end of its body and sways when it is disturbed. The aphid itself is a light bluish color, but it amasses by the thousands on the twigs, small branches, and the undersides of foliage primarily of the American beech, Fagus grandifolia. Infested beech trees can appear to have their smaller branches and twigs covered with snow. In this regard, they look remarkably similar to colonies of the woolly alder aphid, which, as the name implies, is a pest of certain alders.In addition to being occasionally abundant and showy, this species is capable of producing vast amounts of honeydew. Because of the copious amounts of honeydew produced by this aphid, the production of sooty mold can become severe. Control is usually not needed, but it will be eye-catching for your customers.

SpidersBy: Stanton Gill, University of Maryland ExtensionAs we move into October expect to see several orb spiders building webs in the landscape to capture insects. Let your customers know that these spiders are beneficial and feed on a wide range of insects that damage plants in the landscape.

Woolly beech blight aphids make branches look a bit like they are covered in snowPhoto: Diane Knighton, Design With Nature

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This infestation of white prunicola scale was found on cherry laurel in Villanova, PA on September 30Photo: Marty Heidel, Arader Tree Service

White Prunicola Scale Marty Heidel, Arader Tree Service, is finding a lot of white prunicola over the ten days in and near Villanova, PA. He noted that he did not see it in the spring and summer. There a lot of male covers present. The males emerged in the last two weeks so there is a lot of activity. Control: Distance or Talus can be applied now for control.

Looking like the twigs on a tree is one of the defense mechanisms of walking sticksPhoto: Terry Martin, Tree Movers

Golden Rain Tree Bug Rob Orndorff, City of Rockville, sent in photos of the golden rain tree bug (also called a red-shouldered bug) that a resident reported on a city tree. They were present in high numbers.This bug looks very much like the boxelder plant bug but is slightly different in the red coloration patterns on the pronotum and abdomen. The adults are out in the spring and are mating and laying eggs on the golden rain tree foliage. The nymphs will feed on the seed pods, but the damage is not significant and control is generally not necessary.

These golden rain tree bug nymphs feed on seeds; adults do too.Photo: Rob Orndorff, City of Rockville

Walking SticksTerry Martin, Tree Movers, found two walking sticks mating on the outside of his tent at Rocky Gap State Park two weeks ago. These insects obviously blend in well when on woody plants. They feed on foliage.

Note the red ‘shoulders’ of this golden rain tree bug adultPhoto: Mike Raupp, University of Maryland

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Beneficial of the WeekBy: Paula Shrewsbury, University of Maryland

Are yellow jackets good or bad? It’s all about perspective.

A few weeks ago Stanton Gill reported on increased accounts of activity by wasps, which unfortunately resulted in people getting stung by wasps that had entered drinks or food unbeknown to the consumer. At this time of year it is often yellow jackets (Hymenoptera: Vespidae) that are the culprits of this activity as they busily forage for food. Why are yellow jackets so active and noticeable at this time of year? As fall approaches the yellow jacket colony must produce queens (fertilized females) that will ultimately start next year’s colonies. Yellow jacket workers are now searching furiously for insects and sugars to provide the additional nourishment that is needed to prepare these potential queens for the long winter.

Yellow jackets, however, have two sides to them making it difficult to determine whether you should like them or not. On one hand they can cause severe discomfort when you accidently disturb a nest (ex. a lawn mower runs over a nest) and the workers swarm and attack you as they try to defend their nests; or you consume them accidently and get stung. In these cases, I would guess the victims of the sting would have the perspective that yellow jackets are bad! In cases of potential threat it might be best to kill the nests. On the other hand, yellow jackets are beneficial as they provide both pollination and biological control services. As adults, yellow jackets feed on the nectar of flowers assisting in the pollination of many flowering plant species. In addition, yellow jacket adults are voracious predators of plant feeding herbivores such as many species of caterpillars, beetles, and other pests. Yellow jackets contribute toward the reduction of pest populations providing biological control. From the ecosystem services perspective yellow jackets are good!

There are many species of yellow jackets in North America. Yellow jackets are actually wasps not bees. One of the more common yellow jackets around here is the native Eastern yellow jacket, Vespula maculifrons. Typical yellow jackets are about 12 mm (0.5”) long and the queen is slightly larger; they have alternating bands of yellow and black on their abdomens and yellow faces. All females can sting, and sting multiple times, with their modified ovipositor. Interestingly, many species of flies, beetles, and moths that do not have stingers mimic (Batesian mimicry) yellow jackets in their color patterns as form of protection (ex. predators think they have stingers and avoid them). Think about the many species of flower flies (Syrphidae) we see. Yellow jackets are social insects that live in colonies that contain workers and queens (females), and drones (males). Colonies (and their nests) are annual so only last one year. Only fertilized queens overwinter. They leave the nest in the fall and find a protected location such as under tree bark or in logs to hide and make it through the winter. Therefore, once cold weather hits the nest will die and is usually not re-used the next year. In the spring, the fertilized queens will start new colonies. Colonies or nests of yellow jackets can be underground,

Note the yellow and black banding on this adult Eastern yellow jacketPhoto: J.N. Dell, Bugwood.org

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Joint-head grass blooms in late September to early OctoberPhoto: Ross Fornaro, NaturaLawn of America

in dense shrubs or vegetation, tree cavities, or in human-made structures. Nests are built from wood fiber that the yellow jackets chew into a paper-like material. The outer shell of the nest encloses a comb that supports the developing yellow jacket brood (young). Unlike honey bees, yellow jacket nests contain no honey or pollen. Although adults feed primarily on items rich in sugars and carbohydrates (fruits, flower nectar, tree sap, and a sugar material secreted by brood), the larvae feed on proteins (insects, meats, fish, etc.). Adult workers forage for “meat”, return to the nest, and chew and condition the “meat” that they then feed to the larvae. In this regard, yellow jackets kill many insects that are pests in our landscapes and nurseries. Next time you come across a nest of yellow jackets try to remember that they actually provide a pest management and pollination benefits. Consider sharing your lunch with these “mostly” good guys.

Weed of the WeekBy: Chuck Schuster, University of Maryland Extension

Joint-head grass (Arthraxon hispidus), also called small carpet grass, is an annual grass first found in the United States in the early 1970’s. It is native to Japan and eastern Asia. It is found throughout the eastern United States and some parts of the west. Joint-head grass can grow up to 1.5 feet in height, has an oval or lanced-shaped leaf that will be up to 3 inches in total length and up to one half inch wide. Leaves have a heart-shaped base and hair on the margin of the leaf blade. Flowers bloom in late September or early October, appear as individual flowers, and are arranged in groups of multiple spike racemes. Each flower can be 1.5 inches in length. Seeds are yellow in color, thin and about 1/8 inch in length. Stems can root at nodes. The habitat of this plant is most often moist but sunny areas, along streams, roadsides and turf areas that remain wet for extended periods.

Control can be obtained using non selective herbicides that are labeled for areas that are below the mean high water line.

Plant of the WeekBy: Ginny Rosenkranz, University of Maryland Extension

Oxydendrum arboretum, sourwood tree, is a native tree that grows between 20 and 50 feet and is considered an understory tree, one that fits comfortably under the canopy of larger deciduous trees. It is in the Ericaceae family like azaleas and rhododendrons, so it needs acidic moist, organically rich well drained soils and is intolerant of any drought. The leaves are a dark glossy green, about 5 - 8 inches long and finely toothed. They are also sour to the taste, giving the tree its name. In the fall the leaves turn a reliable crimson red, but can also have yellow, red and purple on the same tree, making this native tree a lovely 3 season plant. In the early summer the tree has slightly fragrant small white urn-shaped flowers that bloom on cascading one-sided terminal panicles about 4 - 8 inches long. The flowers are so numerous that the tree looks like it is covered in lace. The look, shape, waxy petals and the fragrance are reminiscent of lily-of-the-valley, so one of the common names is lily-of-the-valley tree. The flowers last for about 3 - 4 weeks, then mature to a dry capsule that ripens to a silver gray in September which contrasts nicely with the crimson fall foliage. Hardy in USDA zone from 5 - 9, this native is listed as being tolerant of deer and can thrive in full sun if watered or partial shade. The

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In early summer, sourwood is covered with small, white, fragrant, urn-shaped flowersPhoto: Ginny Rosenkranz, UME

sourwood tree can be used as a multi-season specimen tree at the edges of a woodland garden or in open woodland. There are no serious insect pests and leaf spots and twig blight are only an occasional problem.

Degree Days (As of October 1) 2015 2014 2013 2015 2014 2013Baltimore, MD (BWI) 3808 3436 3577 Dulles Airport 3743 3263 3560Frostburg, MD 2617 2174 2216 Martinsburg, WV 3506 3281 3275 National Arboretum 4568 4218 4108 Reagan National 4568 4218 4108Salisbury 3756 3800 3905 St. Mary’s City 3896 3589 3701

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

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.

Stanton GillExtension Specialist

sgill@umd.edu410-868-9400 (cell)

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

clement@umd.edu

Nancy HardingFaculty Research

Assistant

Upcoming Conferences:4th Annual TreesMatter SymposiumNovember 4, 2015Early bird registration ends October 7, 2015Location: Silver Spring Civic Center, Silver Spring, MDhttp://www.montgomeryparks.org/activities/things_to_do/fall/trees_matter.shtm

December 10, 2015 Pest Management Conference Details will be posted late September or early October

A list of 2016 conferences will be posted soon