TPM/IPM Weekly Report

Transcription

1 TPM/IPM Weekly Report for Arborists, Landscape Managers & Nursery Managers Commercial Horticulture July 18, 2014 In This Issue... - Planters in Columbus, OH - Mainspring insecticide - Bagworms - Fungicide use survey - Redbud leaffolder caterpillar - Leafroller on witchhazel - Japanese beetles - MDA container recycling - Scale update - Leafdrop on cherries - Gypsy moth - Dogwood sawfly - Amelanchier lace bug Beneficial of the Week Weed of the Week Plant of the Week Phenology Degree Days Announcements IPMnet Integrated Pest Management for Commercial Horticulture extension.umd.edu/ipm 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 Coordinator Weekly IPM Report: Stanton Gill, Extension Specialist, IPM for Nursery, Greenhouse and Managed Landscapes, sgill@umd.edu (office) or (cell) Regular Contributors: Pest and Beneficial Insect Information: Stanton Gill and Paula Shrewsbury (Extension Specialists) and Nancy Harding, Faculty Research Assistant 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) Alternative For Urban Landscapes By: Stanton Gill While out in Columbus, Ohio this week for the Cultivate 14 Conference, I was walking down one of the main avenues near the conference center. For the last couple of years when I walked down this main avenue there were tree pits with either missing trees or slowly dying trees. The city planner decided to take action and try something different. The tree pits were covered by large pavers and concrete pedestals were installed. Attached to the concrete pedestals are planter baskets with an array of tropical Columbus, Ohio has planters lining some of its sidewalks instead of trees

2 and annual plants. The tallest ones were about 10 ft tall. For every tall planter they installed two shorter ones between them. The shorter planters are 4 ft high off the ground. There is not much shade cast by these planters, but they are very attractive. There was an illusion of a colorful sculptured tree planting being projected down the avenue. The city is still using trees, but is planting them on the far side of the sidewalk, away from the pedestrian and vehicle traffic where they are often wounded. I could not find a trickle irrigation line attached to the planters so I would assume they are being handwatered. Adding an automated watering system would enhance this planting. Most people still want to see trees used in urban Planter along sidewalk with row of trees on opposite side in situations, but in some cases getting rid of tree pits background and replacing trees with another type of planting may be the way to go. Planting trees in clusters where they have adequate soil and rooting area and are free from daily wounding is a pretty good idea. Mainspring New Insecticide By: Stanton Gill Syngenta Company received federal registration last Friday for the insecticide, Mainspring. They hope to obtain state registrations by September. This material will be labeled for use in nurseries and greenhouse operations. It is a systemic material that can be applied either by foliar application or as a soil drench. It looks very good in controlling Japanese beetles. Bagworms Debby Smith-Fiola, Landscape Enterprise, LLC, reports this week that bagworms are about 2.45 mm and are feeding on cedar and juniper in Keedysville. Megan DeMarco, Maxalea, Inc, is also finding bagworms in the Towson area. John Speaker, IPM Scout, is finding them feeding on bald cypress in Derwood. With the delay of warm weather this spring, bagworms seem a little smaller at this time of year than usual. Control: Conserve, Orthene, Acelpryn, and Astro are options for control of bagworms Debby photographed the range of sizes of bagworms she is finding at this time of year Photo: Debby Smith-Fiola, Landscape Enterprise,LLC 2

3 Greenhouse Biological Program August 6, 2014 Stormwater Management Program August 20 and 21, 2014 Fungicide Use Survey Request Justine Beaulieu is a graduate student at the University of Maryland who works with the plant pathogen Phytophthora, a fungus-like organism that infects thousands of plant species all over the world. With her research, she is attempting to understand whether or not fungicide application practices in Maryland nurseries are contributing to the resistance of Phytophthora to fungicides throughout the state. Justine has a large collection of Phytophthora species isolated from nurseries across Maryland. In a two-part study she will genotype the collection then examine their sensitivity to several fungicides. Is there a relationship between genotype and fungicide sensitivity? Wouldn t it be interesting to compare these results to what fungicides are actually being used in Maryland nurseries? That s why Justine needs the help of ornamental nursery managers in Maryland. You can help by filling out a short (5-question) anonymous survey asking about your operation and fungicide practices. With this information, Justine hopes to provide a more complete picture of what is happening with fungicide application practices and Phytophthora in the state. Once the surveys are collected the data will be compiled and made available through this IPM newsletter, MNLA s Freestate newsletter, and other publications. Redbud Leaffolder Caterpillar This week, Marie Rojas, IPM Scout, found the redbud leaffolder caterpillar (Fascista cercerisella) in fairly high numbers on both the straight species of Cercis canadensis and the cultivar, Forest Pansy, in Frederick County. Larvae skeletonize leaves while feeding. A rolled leaf (left) and the redbud leaffolder on its only reported host - Cercis canadensis (redbud) Photo: Marie Rojas, IPM Scouts 3

4 Leafroller on Witchhazel Stephen Griner, Scientific Plant Service, Inc., found rolled leaves on a witchhazel from witchhazel leaf roller in Phoenix. Stephen noted that no larvae were found. This small caterpillar rolls the leaves into cylinders and stays within these rolled leaves. This rolled leaf is a sign of activty of a leafroller caterpillar Photo: Stephen Griner, Scientific Plant Service, Inc. Japanese Beetles Japanese beetle adult activty continues throughout the area this week. Marie Rojas, IPM Scout, is finding them wreaking havoc in the nurseries, especially on Stewartia, Ulmus, Prunus, Tilia, and Malus. Stephen Griner, Scientific Plant Service, Inc., is noting Japanese beetle damage as well. Mark Schlossberg, ProLawn Plus, Inc., is finding them on Knockout rose flowers in Baltimore. John Speaker, IPM Scouts, reports them still active, and noted this year he is even fidning them on birches. Heavy damage from Japanese beetles on apples in a nursery row Photo: Marie Rojas, IPM Scout Japanese beetles infesting the flower of a Knockout rose Photo: Mark Schlossberg, ProLawn Plus, Inc. Maryland Department of Agriculture Pesticide Container Recyling MDA has a brochure on the dates and details of the pesticide container recycling program which is available at: 4

5 Scale Update Pine Needle Scale, Chionaspis pinifoliae (armored scale) Monitoring pine needle scale on Pinus mugo in Bowie found females with eggs for the second week in a row indicating the second generation crawlers will soon follow. There are two generations a year of this scale. As of Tuesday, July 15th the Degree Days in Bowie were 1505 DD. We will continue to monitor this scale and let you know when the crawlers are active. Host Plants: Mugo and Scotch pine are preferred, but other pines and spruce are frequently attacked. Control: Many lady beetles and parasitic wasps feed on this pest; therefore, careful monitoring for predators and parasitoids, as well as using pesticides with low toxicity to beneficials, can allow biological control to suppress the population. However if control is warranted, use a summer rate of horticultural oil Adult female pine needle scale with eggs. Waxy cover was flipped off. Photo: N. Harding, UMD or an insect growth regulator (IGR) such as Distance to target crawlers. Be cautious of using oil with the high humidity we are having READ the LABEL. White Prunicola Scale (WPS), Pseudaulacaspis prunicola (armored scale) Monitoring WPS populations in Laytonsville on Prunus yedoensis (Yoshino cherry) found active CRAWLERS! As of Tuesday, July 15th the Degree day (DD) readings in Laytonsville were 1738 DD. If the degree day accumulations in your area are near 1738 you should closely monitor plants infested with WPS. If crawlers are active, it is time to treat. Monitoring: WPS has 3 generations per year. The second generation crawlers are active now. Host plants: Preferred hosts include Prunus, especially Japanese flowering cherry, lilac, and privet. Control: When crawlers are out, apply pyriproxyfen (Distance) or buprofezin (Talus) mixed with 0.5-1% horticultural oil for control Pine Oystershell Scale, Lepidosaphes pini (armored scale) We are monitoring pine oystershell scale (also called Oriental pine scale) on Pinus densiflora (Japanese red pine) in Laytonsville. As of Tuesday July 15th females with eggs were found indicating crawlers will soon follow. But there are NO crawlers yet. Degree Days in Laytonsville were 1738 DD. Monitoring: The adult female cover is oyster-shell shaped, straight or slightly curved, moderately convex, and light brown. The scale is usually found near the needle sheath in last year s needles. We will continue to monitor this scale and report when crawlers are active. Host plants: Pinus spp. Close-up of a crawler of white prunicola scale Scale flipped over to show adult female pine oystershell scale with whte eggs under the waxy cover Photo: N. Harding, UMD *Degree data totals as per Weather Channel website at 5

6 Premature Leaf Drop on Cherries David Keane, Howard County Recreation and Parks, sent photos of Yoshino cherries in his neighborhood in Frederick showing trees that are dropping leaves like it s November! The wet weather in the spring was good for infection of cherry leaf spot disease so this premature leaf drop will continue in our area. Cherry leaf spot disease is causing infected cherry trees to drop foliage early this year Photo: David Keane, Howard County Recreation and Parks Gypsy Moth Wayne Noll, City of Rockville, reported finding a gypsy moth egg mass on a black cherry in Rockville this week. He noted that he hasn t seen one in Rockville in over 10 years and that it was the only egg mass that he saw in the area. Control: Physically remove and destroy egg masses where possible. A gypsy moth egg mass on black cherry Photo: Wayne Noll, City of Rockville Dogwood Sawfly Marie Rojas, IPM Scout, found dogwood sawfly larvae on a Cornus sericea in a landscape. Examine the foliage of dogwoods this week for the larvae. Dogwood sawfly will eat all but the midrib of the leaf. These sawflies overwinter in the last instar stage. After the second molt, the bodies of the larvae become covered with a white powder-like material to mimic bird droppings which helps to protect them from their enemies. At their final molt they have a spotted pattern to camouflage them as they crawl over leaf litter. There is only one generation per year. Control: Options include Conserve, synthetic pyrethroids, and carbaryl. Mid instar dogwood sawfly larvae showing three with the waxy covering and one without it. The final instar (not shown) has black spots and no white waxy covering. 6

7 Amelanchier Lace Bug John Speaker, IPM Scout, is finding the second generation of lace bugs active in Derwood this week. Monitoring: Look for nymphs and adults on the undersides of foliage. Feeding causes yellow stippling on the leaves. Lace bugs also leave black fecal spots on the undersides of the foliage. Control: Options include Orthene, Tristar or Horticultural oil (need to make contact with insects on the undersides of the leaves and check label for temperature precautions). Amelanchier lace bug stippling damage on top side of leaf (left) and nymphs and fecals spots on the underside of a leaf (right) Beneficial of the Week By: Paula Shrewsbury, UME Dustywings relatives of lacewings and antlions Dustywings are predatory insects that are in the order Neuroptera, which are known as net-winged insects due to the abundant venation in their wings. Dustywings are in the family Coniopterygidae and related to lacewings and antlions. Dustywing adults are mm in length and their wings and body is covered with white waxy powder. They have long thin antennae, beak-like mouthparts, and their wings are held tent-like over the body. At first glance dustywings look like whiteflies, but dustywing legs and antennae are longer, mouthparts differ, and wings are more strongly roof-like in position. Dustywing larvae are similar in appearance to green or brown lacewing larvae. They have 2 needlelike mandibles that work like straws to suck the contents out of their prey s body. There are over 400 known species of duskywings and they occur worldwide and throughout North America. They are thought to be very primitive insects with fossils going back to the Jurassic period. Dustywings are arboreal so their main habitat is trees and shrubs. Most species are active in the spring and fall. They are crepuscular so are active during dawn and dusk. Adults Dustywing adults look similar to whiteflies but are predators and good to find on your are attracted to lights at night. The life cycle of dustywings consists trees and shrubs. of two generations per year and most overwinter as larvae. Cocoons Photo: Cheryl Moorehead, individual, are found on the underside of leaves or on bark. Adults fly slowly Bugwood.org around plants and lay single yellowish pink eggs on leaves or bark. Both adults and larvae are generalist predators and feed on 7

8 soft-bodied arthropods such as aphids, mealybugs, spider mites, whiteflies, and scale insects. The larvae also will feed on eggs of various arthropods. Dustywings are one of many beneficial insects that contribute to biological control of plant feeding insects in ornamental landscapes and nurseries. Dustywing larvae look similar to their lacewing relatives and are predators of many soft-bodied arthropods. Photo: M. Raupp, UMD Weed of the Week By: Chuck Schuster, UME Spotted spurge, Euphorbia maculata, is very similar to prostate spurge. The summer annual is found growing throughout the eastern United States in lawns, landscapes and nurseries. Spotted spurge is a prostrate summer annual, which forms dense mats growing to fifteen inches in diameter. It is easy to identify as it will secrete a milky sap when the stems are broken. The root system is most noticeably a thin and fibrous but a thin taproot is also present (photo B). Leaves are from one eighth to one half inch in length, (4-14 mm) opposite with a maroon or purple spot on the upper leaf surface (Photo A). The leaf margin is very finely toothed, which may Photo A: Note the color on the spotted spurge leaf Photo: Chuck Schuster, UME be very difficult to discern. It prefers a compacted soil with full sun. Turf aeration is a tool for prevention. It will grow well in sidewalk or paver openings (Photo C). It prefers dryer settings. Irrigation can be used but should include deep soaking rather than shallow waterings. Flowers occur in late June through October. Photo B: Note the fibrous roots with the thin taproot of spotted spruge Photo: Chuck Schuster, UME 8

9 Control of Spotted spurge can be obtained through the use of pre emergent materials that include prodiamine (Barricade), isoxaben (Gallery), trifluralin (Treflan) and with post emergent products that would include Fusilade II, Glyphosate products. Photo C: Spotted spurge growing through an opening in the sidewalk Photo: David Jefferson, Express Certification Plant of the Week By: Ginny Rosenkranz, UME Clematis Sapphire Indigo Clematis cleminov 51 is a summer blooming clematis that is covered with large 5-inch dark sapphire blue flowers from early to late summer. This clematis is considered a groundcover shrub, but it can also climb up a trellis or be used in a container or even in a hanging basket. The rich purple color of the recurved petals is echoed in the deep purple stamens, and the center is so dark it looks like a deep purple eye. Sapphire Indigo doesn t need pruning to keep its very compact arching shape of 3-4 feet tall and wide. It does best in full sun to very light shade with moist, loamy well drained soils. This clematis is cold hardy from USDA zones 5-9. Like all clematis, it is susceptible to clematis wilt, powdery mildew, rust and root rot. Clematis Sapphire Indigo Clematis cleminov 51 Photo: Ginny Rosenkranz, UME PLANT PLANT STAGE (Bud with color, LOCATION First bloom, Full bloom, First leaf) Buddlea hemsleyana Full bloom July 13 (Silver Run) Clethra acuminata Full bloom July 13 (Silver Run) Diervilla sessilifolia Full bloom July 13 (Silver Run) Elliottia racemosa Full bloom July 13 (Silver Run) Eutrochium purpureum (Joe pye weed) Bud July 18 (Ellicott City) Monarda fistulosa Full bloom July 16 (Ellicott City) Oxydendrum arboretum Full bloom July 13 (Silver Run) Platycrater arguta Full bloom July 13 (Silver Run) Rhododendron prunifolium Firstbloom July 13 (Silver Run) Stokesia laevis Purple Parasols Full bloom July 13 (Silver Run) Veronicastrum virginicum Full bloom July 16 (Ellicott City) 9

10 Degree Days (As of July 17) Baltimore, MD (BWI) Dulles Airport Frostburg, MD Martinsburg, WV National Arboretum Reagan National Salisbury St. Mary s City To check degree day (DD) accumulations in your local area go to: 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 Conferences Virginia/Mid-Atlantic Regional Aquaculture Best Management Practices Training Workshop July 23, :30 AM 4 PM. Location: Hampton Roads Agricultural Research and Extension Center 1444 Diamond Springs Road, Virginia Beach, Virginia. Free, lunch provided. Pre-registration required: Attendance will be limited to first 50 pre-registrants. To register please contact: Gail Jamison: , gjamison@vt.edu PANTS14 - Penn Atlantic Nursery Trade Show July 30-31, 2014 Pennsylvania Convention Center, Philadelphia or Greenhouse Biocontrol Conference*** August 6, 2014 Location: Maritime Institute, Linthicum, MD Fertilizr Applicator Recertification Seminar Location: Maryland Department of Agriculture, Annapolis, MD Time: 9:30 a.m. to 11:30 a.m. Choose any one of the following dates for recertification: August 7, 2014 or September 3, 2014 Seating is limited, register now. Cost: $12, which includes breakfast. Registration with payment is required no later than one week before the class date. For more information, call Stormwater Management Program*** August 20 and 21, 2014 TWO Locations: August 20 - Montgomery County Extension Office, Derwood, MD August 21 - Robinson Nature Center, Columbia, MD *** For brochures and registration information on these programs CONTRIBUTORS: Stanton Gill Extension Specialist sgill@umd.edu Paula Shrewsbury Extension Specialist pshrewsb@umd.edu Karen Rane Plant Pathologist rane@umd.edu Chuck Schuster Extension Educator cfs@umd.edu David Clement Plant Pathologist hgic.umd.edu Andrew Ristvey Extension Specialist aristvey@umd.edu Ginny Rosenkranz Extension Educator rosnkrnz@umd.edu 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. The information given herein is supplied with the understanding that no discrimination is intended and no endorsement by University of Maryland Extension is implied. 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.