TPM/IPM Weekly Report

Transcription

1 TPM/IPM Weekly Report for Arborists, Landscape Managers & Nursery Managers Commercial Horticulture July 3, 2014 In This Issue... - Weather update - MDA programs - Request for scale - Emerald ash borer in Japanese beetles - Lace bugs - Sooty mold and scale - Fungus in mulch - Bear relocation - Fall webworms - Spangled galls on oak - Hibiscus sawfly - Potato leafhoppers - Winter damage - Fletcher scale - Fungicide use survey - Red maple problems Beneficial of the Week Weed of the Week Plant of the Week Phenology Degree Days Announcements 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) Since July 4 is on a Friday the IPM Alert is a little early this week Happy 4th! Weather and Its Impact on Plants This week we moved into weather in the upper 90s that we have learned to expect in July. This hot weather will quickly collapse foliage or brown needles on plants with compromised root systems. We usually see an increase in calls and s about plants just suddenly dying at this time of year. Actually the plant was often under stress earlier in the season, but with the advent of hot weather the plant loses moisture rapidly and collapses. 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 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: Maryland Department of Agriculture Workshop on How to Get Maryland Product to Canada July 9th (8:30 to 12:00) Free - But need to register by July 7 (next Monday) Contact Theresa Brophy at

2 Plants With White Prunicola Scale Needed for Research Paula Shrewsbury and Nancy Harding are in need of trees (Prunus ssp. or Syringa ssp.) infested with white prunicola scale to conduct a research trial. They need a minimum of 5 trees. If you possibly have a site, contact Nancy Harding at nharding@umd.edu with your contact information. Emerald Ash Borer At the June 26th MNLA nursery field day, Dick Bean, MDA, reported that EAB has been detected in Carroll County and Baltimore City in Japanese Beetles At this point, Japanese beetle adults are out in force. We observed gobs of them feeding on Knockout roses in Glenwood on Monday. Several people ed to report the adult beetles consuming zinnias, little leaf lindens, Aronia (chokeberry), cannas, crape myrtles, raspberries, cherry trees, apple tree, blueberries, hibiscus, oakleaf hydrangeas, plums, birch, elms, pieris, rose of Sharon, and grapes. The population has exploded in Just what we needed a banner year for a defoliator. Annette Ipsan, Washington County Extension, is reporting the beetles are now active in Western Maryland. Annette has seen or received client calls about heavy infestations on roses, grapes, raspberries, Virginia creeper, pussy willows and potatoes. She noted that on her grapes and A large number of Japanese beetles were found feeding on roses on June 30 Photo: David Clement, HGIC pussy willows she is finding more than a dozen on a single leaf. Gary Huntsberger, Greenkeeper, is also reporting the start of beetle activity in Washington County. Control: Acelepyrn in landscapes, acephate, carbaryl and bifenthrin are all labeled for control. Neem is a biorational product that can be used and may need to be reapplied when beetles return to the plants. Lace Bugs Marie Rojas, IPM Scout, is noticing a lot of lace bugs! Marie has found high numbers of lace bugs on Amelanchier (various cultivars), Platanus Bloodgood, several Crataegus species, and Quercus x Regal Prince. Is anyone else noticing a higher than usual number of lace bugs? Monitoring: Look for yellow stippling of new growth. Look on the underside of foliage for nymphs, adults, and black fecal spots. Damage on new growth indicates eggs have hatched and the new generation has started to feed. Control: Get good coverage of horticultural oil on the underside of foliage to reduce populations. Many products are labeled for lace bugs. Sycamore lace bug adults and black fecal spots on the underside of a leaf 2

3 Sooty Mold and Scale Many landscape managers are reporting large populations of lecanium scale including oak lecanium and calico scale (a type of lecanium scale). Since the populations are very high, they are excreting tons of honeydew this season. Combine the honeydew with frequent rainstorms and high humidity and you have a lot of dark sooty mold growing on foliage this season. Control: The scale can still receive applications of Talus or Distance at this time of year. Another option is a basal bark application of dinotefuran or a soil drench application. Sooty mold as a result of this fletcher scale producing honeydew is evident on this arborvitae Mulch Fungus and David Clement We were visiting a landscape site this week and saw two decomposer (feeding on dead material) fungi growing in mulch beds. The one fungus is called the stinkhorn fungus. The common name of stinkhorn is very descriptive of how bad they smell. They tend to show up in mulch after rainy periods followed by warm humid weather. You don t need to do anything about them since they will not damage living plant material. The other fungus looks like a yellow foamy mass that looks like the neighbor s dog vomited in their flower garden and is appropriately called the dog vomit fungus. It is the slime mold, Fuligo septica. It is blob-like in shape and bright yellow in color which will fade to a sickly orange brown as it matures over the course of a few days. The end result is a powdery gray-brown pile that will erupt into a wisp of spores being released when it is disturbed. This cloud of fine dust is the way it spreads its spores to a new spot. It has no preference as to the type of mulch. Slime molds feed on the bacteria that are feeding on the mulch, not actually eating the mulch directly. Control is not necessary unless you are unhappy where it is appearing. Just shovel it off to the compost pile. The dog vomit fungus becomes powdery and will release spores when distrubed Photo: David Clement, HGIC Bear Relocation Bernie Mihm, Fine Earth Landscape, sent an on the black bear found at NIH 2 weeks ago. He pointed out it was relocated to Poolesville, not Washington County. Fall Webworms We are still getting reports a lot of fall webworm activity. Mari Rojas is is finding high populations in Montgomery County. Prune out webbed branches. There are many predators and parasites that help keep this pest below damaging levels. 3

4 Spangled Galls Ron Rubin, Thrive, Inc., sent in nice sample of white oak covered with anthracnose and with small raise circled structures. The small round circles are the early stage of spangled galls caused by the cynipid wasp, Neurotrus quescusbaccarum. Control is not feasible for this pest. Later in the season these galls enlarge and look like small saucers on the foliage. The arrow shows the early stage of a spangled gall on white oak Hibiscus Sawfly Ginny Rosenkranz is reporting feeding damage by hibiscus sawfly on the Eastern Shore. We have observed some feeding on Hibiscus moscheutos plants here at the research center in Ellicott City. Monitoring: Examine the undersides of foliage for the presence of the green colored caterpillar. Look very carefully they camouflage well. Look for defoliation damage. Sawflies have more than 5 pairs of prolegs on the abdomen. Control: Spinosad works well. Bifenthrin also gives good control but must be directed to the undersides of the foliage. The larvae can be hard to see against the underside of the hibiscus foliage Photo: Ginny Rosenkranz, UME Potato Leafhoppers Are Very Active Potato leafhoppers have been extremely active in the last three weeks and we are seeing a lot of damage on new growth of red maples. The activity is peaking a little later this year. We should see another small peak of activity in later July to early August. Materials to control leafhoppers: Thiamethoxam (Flagship), Acephate (Orthene), and Grandevo. Potato leafhoppers cause leaves on the growing tips of maple to harden and curl 4

5 Winter Damage Can Still be Found Kevin Nickle, ProLawn Plus, Inc., noted the total death of Leyland cypress from winter injury along the road. Some people are still waiting to remove their plants. Karen Wimsatt, Master Gardener, has a bay leaf planted in her herb garden which looked horrible, pruning did not help. When going to plant something new near the dead plant Karen noticed little sprouts at ground level and noted that it is recovering well. Karen also has a Jackfrost gardenias on which she is now seeing new green leaves. The effects of the cold winter are still evident on this group of Leyland cypress trees Photo: Kevin Nickle, ProLawn Plus, Inc. Fletcher Scale We collected samples of fletcher scale on arborvitae in the Laytonsville area in Central Maryland on Wednesday. The 3rd instar female covers are swollen and most of the eggs have hatched, but we are still finding females with eggs under their covers. There were several settled 1st instars. The fletcher scale is commonly found on arborvitae but is also found on yews and junipers. Be sure to look for the brown female covers that look like small helmets on the branches and leaves. Control: Talus or Distance can still be applied to control the crawlers and settled crawlers. The female covers of fletcher scale look like brown helmets 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. 5

6 Rapid Red Maple Tree Death Stanton Gill and David Clement A landscape company asked us to examine some red maples that were in the later stages of death. The trees had been installed by a different landscape company about 6 years ago. We were a little baffled when we first examined the trees since the growth from 6 years ago appeared to be vigorous, but had been declining each year with shorter and shorter spaces between the bundle scars on the branches indicating a slow decline. There was no vascular discoloration that is typically found with a verticillium wilt infection. We noticed that all of the declining trees had trunks that looked like telephone poles stuck in the ground. The healthy maples had more of a flair to the trunk at the base. In digging around the base of the declining trees we found 6 8 of topsoil and mulch over the original tree flair. Also, the nylon binding rope was still around Twine left at the base of this tree caused it to decline over a 6-year period and eventually die Photo: David Clement, HGIC the base of the declining trees. The twine was cutting deeply into the crown of the plant causing slow death to occur over several years. The healthy trees in the row had the nylon rope removed from the base of the trees. We are mentioning this situation since you may be called in to diagnose a declining tree in a customer s landscape. Make sure to examine the base of the plant and make sure that the nylon twine surrounding the base of the plant has been cut away to prevent girdling of the plant. Beneficial of the Week By: Paula Shrewsbury, UME Caterpillar eating wasps Monobia quadridens (Hymenoptera: Vespidae), the four-toothed mason wasp, is an omnivorous wasp that feasts on caterpillars and pollen. Monobia is a solitary potter wasp found the eastern U.S., New Mexico, Kansas, and Wisconsin, in addition to other areas of North America. Monobia is mostly black with a white band on its upper abdomen and few white patches on other areas of its body. The wing span is about ½ for males and slightly larger for females. Males have a white patch on their face, females have all black faces. As adults a large proportion of their diet is pollen, making them good pollinators. They also feed on a diversity of smaller caterpillar species making them good predators. The wasp, Monobia quadridens, is sunning itself on a leaf Photo: Whitney Cranshaw, Colorado State University, Bugwood.org Monobia s life cycle consists of two generations per year. Adults emerge in the spring, go through a complete summer generation, and then the next generation overwinters as pupae in nesting chambers. They are active from around May October. Monobia are often seen in open habitats with flowers. Each female selects her own nest location (solitary) from a diversity 6

7 of natural cavities such as abandoned tunnels of carpenter bees or on occasion ground nesting bees; old mud dauber nests; and hollow plant stems. Monobia females provision their tube-like nests with caterpillars for their young. Within a tube a female makes multiple cells. A female Monobia hunts for caterpillars, stinging and paralyzing them with her venom, and then flies them back to the nest. The female places multiple paralyzed caterpillars into her nesting tunnel. She lays an egg in the tunnel with the caterpillars and then seals the tunnel section with a mud partition creating a cell. Interestingly, the next cell in the tunnel she makes is empty, and then the next contains caterpillars and her egg. It is thought that these empty cells are used to fool parasitoids of Monobia larvae into thinking the tunnels are empty. A female makes approximately 5-7 cells per nest, with the last outer most cell always being empty. A female may have more than one nest. This nesting behavior is also common for mason bees. Like most wasps the females can deliver a sting which contains venom using their ovipositor. For Monobia the pain from this sting is described as comparable to that of a bald faced hornet (ouch!). Interestingly, unlike most wasps the males of Monobia can also deliver a sting. Since males lack an ovipositor they use the tip of their abdomen and does not inject venom which results in pain similar to a pin prick. Most solitary wasps are not aggressive. So unless you are trying to catch them with your bare hands you should have no worries. I have a few flying around my patio and flower beds and they are busy finding nesting sites and food, not trying to sting people. It seems many of the beneficials we discuss use pollen and nectar as a food resource. So keep planting flowers to attract and retain beneficials! Weed of the Week By: Chuck Schuster, UME Common lespedeza, Kummerowia striata (formerly Lespedeza), often called Japanese clover, is the plant of concern this week. This plant can be found in both landscape and turf. It starts flowering at this time of year. This summer annual forms a dense mat that can grow up to eighteen inches in diameter. It prefers thin turf, compact soils, and A close-up of the trifoliate leaves Photo: John D. Byrd, Mississippi State University, Bugwood.org lower ph. It is extremely drought tolerant. Common lespedeza has a shallow woody taproot. Leaves have three leaflets on a short petiole with a shape similar to Oxalis stricta (yellow woodsorrel). It is also similar to black medic, Medicago lupulina, but black medic does not have a spur at the tip of each leaflet like common lespedeza. Black medic also has A clump of lespedeza Photo: Chuck Schuster, UME yellow flowers. Stems will branch often, with a limited number of downwardly turned hairs. Common lespedeza flowers are solitary or can occur in groups of 2 to 5 in a spike like-floret, pink to purple in color. Control of common lespedeza in turf is accomplished using many of the post emergent three way turf herbicides including 2, 4D, dicamba, and metasulfuran. In the landscape glyphosate products work well. Manage soil fertility and ph for optimum plant growth of desired species. 7

8 Plant of the Week By: Ginny Rosenkranz, UME Ilex crenata, Japanese holly, is sometimes called a box leafed holly for its resemblance to boxwood plants. Like all hollies, Ilex crenata has leaves that grow on the alternate side of each stem, distinguishing hollies from Osmanthus (false holly). Their flat evergreen leaves are a dark lustrous green all year, giving much needed color to the gardens in the winter. Their very dense growth make then a very solid fixture in the landscape. Ilex crenata Steeds has very dark glossy green foliage that becomes darker as they age, with small white fragrant flowers in the spring. The female plants will have dark black berry-like drupes in September and October which persist until spring, but as they are borne under the foliage they are not very showy. Its growth pattern is an upright pyramidal form, making them excellent specimen plants, in mass plantings as a hedge, and as a part of the foundation plantings around a home or building. Holly Steeds grow 7-10 feet tall and 5-8 feet wide. They are hardy from USDA zone 5-9 and 9-6 in the AHS Heat zone, and thrive in moist acidic, but well drained soils in full sun to partial shade. A light application of mulch will help the plants retain moisture during hot dry weather. Like all Ilex crenata, the Steeds holly can be pruned to a more ridged look or a hedge, but their natural shape is very nice. Pests include spider Ilex crenata Steeds Photo: Ginny Roseknraz, UME mites, and black knot disease (Thielaviopsis basicola), although they are not as susceptible to black knot disease as other I. crenata hollies. PLANT PLANT STAGE (Bud with color, First bloom, Full bloom, First leaf) LOCATION Albizia julibrisson Full bloom July 2 (Columbia) Phlox Sherbert Cocktail First bloom July 3 (Ellicott City) Saururus cernuus (lizard s tail) Full bloom July 2 (Ellicott City) Degree Days (As of July 2) 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. 8

9 Upcoming Conferences Mid-Season Aronia Tour*** July 8, 2014, 5:00-7:30 p.m. Location: Wye Research and Education Center, Queenstown, MD Contact: Andrew Ristvey, , There is no charge, but you need to register by July 1. PGMS Green Industry Professional Field Day July 17, 2014 Location: American University, Washington D.C. Green Industry Field Day Brochure 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 Program components: What are Aquaculture Best Management Practices (BMPs)?; FDA aquaculture regulations, guidelines, and future trends/considerations; State regulators/regulations, and VDACS Fish Health; All about Aquaculture Feeds; BMPs for hatcheries, raceways, ponds, cage culture, hydroponics/aquaponics, recirculating aquaculture systems, harvest and post-harvest handling 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.