TPM/IPM Weekly Report

Transcription

1 TPM/IPM Weekly Report for Arborists, Landscape Managers & Nursery Managers Commercial Horticulture July 17, 2015 In This Issue... - Update from Cultivate 15 - New pesticides - Dealing with bulb pests - Mimosa webworm - A different caterpillar - Eriophyid mites on Echinacea - Banded ash clearwing borers - Japanese beetles - Cicada killer - Kousa dogwoods - Scale update - Great golden digger wasp 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 (Extension Specialist, Wye Research & Education Center) Design, Layout and Editing: Suzanne Klick (Technician, CMREC) 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 What Did I Learn in Ohio? By: Stanton Gill, UME On Sunday thru Tuesday I was at Cultivate 15 in Columbus, Ohio. First off, I have to tell you flying out of BWI Sunday was an adventure. It seems everyone is flying in midsummer and the parking lots are totally full and the terminal even fuller, if that is possible. When I landed in Columbus I asked the shuttle driver how long it had been raining on Sunday. His answer was 2 and a half months. It has been wet in Maryland lately but the midwest is really getting dumped on. Michigan had so much rain it pretty much totaled their cherry crop and Crape myrtle Cherry Mocha is one of the new dwarf crape myrtles on the market that to about 2.5 tall is damaging their apple crop. Nursery growers from the mid-west told me they cannot get in their fields to summer dig trees. We had many people from California listening to the whining about too much rain and they appeared to be envious. If we could just send it their way for a while it would be nice. On the plant end of things, there was a plethora of relatively new dwarf crape myrtles that are being introduced into the industry. These new miniature crape

2 myrtles are not any more winter hardy, but they are only 2.5 ft. tall so sitting closer to the ground the snow cover (if it occurs) may provide some winter protection. For woody shrubs one of the cooler plants I saw was the hybrid Hypericum x inodorum, Hypearl TM Compact Red. It was under two feet tall and had beautiful fruits that change from green to The fruits of Hypericum Hypearl TM Compact white to orange. It makes Red change from green to white to orange a very attractive plant as a specimen in the landscape. One of the weirder and very popular plant combos this season was the potato/tomato grafted plant. I don t see why it is so popular, but many 2 Plants on display at Cultivate 15 included a cherry tomato grafted onto a potato garden center owners attending and greenhouse growers said they could not keep enough in stock in Basically, it is a cherry tomato plant grafted on a potato. I guess the public likes weird, novel stuff. For cut flower growers there was a new stamen free, double flowering Oriental lily called Rose Lily and you can view it at It is very attractive and lacks the stamens that drop pollen in people s house thus eliminating the mess. New in Pesticides from the Ohio Meeting By: Stanton Gill, UME I sat in on a seminar on new chemistry. SePro Company has an interesting class of chemistry that they are calling insect behavior modifiers. I had never heard of this term before so I asked their rep to explain it to me. He said when you apply the material to the foliage the insect that lands on the foliage and feeds will then start to wander around within 4 to 6 hours. It may flip on its back, but it does not die right away. It just stops feeding and keeps wandering around until it runs out of energy and dies. Evidently, the IRAC coding system does not have a class for this mode of action so the company is calling it the insect behavior modifier IBM (wow we better be careful with this acronym) until IRAC (Insect Resistance Action Committee) can come up with a new classification. It is not systemic, but it is translaminar in action. It looks good for controlling whiteflies, aphids, leafhoppers, chilli thrips and mealybugs. The product that is an insect behavior modifier is called Rycar and the chemical name is pyrifluquinazon. It is presently just labeled for herbaceous and woody plants in a greenhouse, but the company has plans to expand its use in the landscape and the nursery in the near future. Met52 SC is now being sold by Monsanto BioAg Division. Four years ago we did a lot of testing of this product for thrips and mite control in greenhouses and it was very effective. The product contains an entomopathogenic fungus called Metarhizium anisopliae. The product contains conidia of the fungus that are sprayed onto the insect and leaf surface. When the conidia gets on the cuticle of the insect it germinates and forms appressonium infection structures, then the spores penetrate the cell walls of the insect by physical and enzymatic means. Protoplasts form in the hemolymph (insect blood) and kills the insect. Hyphae grow from the cadaver penetrating out through the cuticle to produce more spores which could infect other insects.

3 It is labeled for use in greenhouses, and we have used it in mist propagation greenhouses with good success. It has performed well for tetranychid mites and western flower thrips. It is reported to work on whitefly, but we have not conducted tests on this pest. An Interesting Way of Dealing with Bulb Pests By: Stanton Gill, UME At the Ohio meeting I had a chance to chat with Brent of Brent and Becky s Bulb Company of VA. He mentioned that the Dutch used an interesting technique to control nematodes in the soil. When they finish with bulb production after a couple of cycles in a field, they flood the field with water and let it sit for a month or so before draining it. I spoke with Ko Klaver of the Dutch Bulb Company about this technique. He said that in bulb fields they not only build up nematode populations, but rodents become a big problem after a couple of years. They break a dike and flood the field with about a meter of water and let it sit. This flooding takes care of rodents and nematodes. They then do a practice they call re-awakening the soil. They pump out the water and dry the land out. The rodent and nematode populations are greatly reduced. Then, large quantities of compost are brought in and tilled into the soil to re-awaken it. They have been doing this technique since the mid- 1990s. Ko said his uncle was one of the originators of this practice and it is now widely used in Holland. it is an interesting IPM approach to dealing with soil pests. Mimosa Webworm Bob Mead, Mead Tree and Turf, reported that mimosa webworm larvae are webbing together the tips of honeylocust foliage together in Anne Arundel County. This activity is damage from the first generation of the summer. Control options include: Acelepyrn as foliar spray, TriStar spray, Orthene (Acephate) or Conserve (Spinosad) sprays. The first generation of mimosa webworm larvae will pupate in mid to late July We Love the Weird Ones By: Stanton Gill, UME Many have tried to send us the weirdest insects, but Andrew Ristvey of WYEREC wins this week with his entry. It is the wavy emerald moth caterpillar. This caterpillar takes petals off plants and attaches them to its back with silk to protect itself from predators and parasites.the wavy emerald moth caterpillar feeds on plants in the family, Asteraceae. Caterpillars regularly replace old and faded petals. They are harmless, but interesting. Keep the weird insect pictures coming. The wavy emerald moth caterpillar does what it can to blend in well with the flowers of its host plant Photo: Andrew Ristvey, UME 3

4 Eriophyid Mites on Echinacea By: Gaye Williams, MDA Deb Hayes, MDA, sent an image of Echinacea Hot Papaya from a Cecil County garden center to the MDA lab. It shows witch s broom, a proliferation of leaf tissue instead of floral parts, and sporadic ray flower development. We initially thought it was symptomatic of aster yellows phytoplasma. However, Karen Rane mentioned that she had previously encountered an unnamed eriophyid mite producing the same symptoms. Flowers from the Cecil County site and a garden in Davidsonville were collected and sliced open, each revealing thousands of this unnamed coneflower rosette mite per head. The 200 micron long, pink four-legged mites can be [barely] seen using a hand lens. Control the problem by removing and destroying affected flowers. Removal of vegetation in fall has been suggested. Note green proliferation and lack of ray flowers on some heads of the eriophyid- infested Echinacea Hot Papaya. The insert shows flowers and, at left, cross-section of flower head where mites abound. Photo: Deb Hayes, MDA This closeup of the flower cross-section shows a cluster of the tiny, banana-shaped mites Photo: Deb Hayes, MDA Banded Ash Clearwing Borer Dave Keane is seeing frass being kicked out of ash trees in Frederick by the larvae of banded ash clearwing borers. This caterpillar will pupate next month and moths will emerge in early September. Control: A protectant spray of permethrin or bifenthrin can be applied after adults are out. A sign of banded ash clearwing borer larvae is frass as the base of ash trees Photo: Dave Keane MDA Pesticide Container Recycling Program for 2015 For more information: 4

5 Japanese Beetles Japanese beetle adults continue causing feeding damage on many plants this week. Annette Cormany, UME, is seeing large numbers of adults in Washington County on favored plants including a peach tree with an impressive population. She noted how they are so thick on some of the fruit that you cannot see the peach. Marie Rojas, IPM Scout, is reporting that Japanese beetles continue to wreak havoc on all manner of plants. She notes that Tilia and Prunus cerasifera Thundercloud and Cripoizam are completely defoliated! Peaches attract a lot of Japanese beetles Photo: Annette Cormany, UME Japanese beetles have almost complete defoliated this Tilia tree Photo: Marie Rojas, IPM Scout Cicada Killer Will Lowery, Salisbury University, watched a cicada killer in action last Friday. He saw a cicada land in a flower bed with the cicada killer on top of it. He noted how the cicada was at least twice as large as the killer, so the cicada killer was having a hard time moving with it. The female cicada killer takes the paralyzed cicada back to Kevin Wolcott found this cicada nymph its burrow to feed its young. while digging in the soil Photo: Kevin Wolcott, Dirt 2 Turf At this time of year, listen for cicadas and watch for cicada killer activity Photo: Will Lowery, Salisbury University Kousa Dogwoods Jon Cholwek, Bonifant Tree Service, is seeing several Kousa dogwoods with severe dieback and dying trees in Chevy Chase and NW D.C. Several factors are likely contributing to this situation. The new growth of Kousa dogwoods tends to wilt when it gets hot. The plants recoup from these occurrences. We re not seeing signs of winter damage. With the high moisture, there may be root damage. If anyone suspects a disease problem, you can get a sample to Karen Rane ( or rane@umd.edu) in the Plant Diagnostic Lab. 5

6 Scale Update By: Nancy Harding, UMD Pine Needle Scale, Chionaspis pinifoliae (armored scale) The start of the second generation crawlers of pine needle scale were found on Pinus mugo in Bowie on Monday July 13. The eggs (crawlers) may hatch over a period of two to three weeks and will seek feeding sites on the previous year s needles. Once they have inserted their mouth parts through a stoma, they remain at the site for the rest of their lives. Settled crawlers are flattened and yellow. There are two generations per year. The degree days (DD) in Bowie on July 13 were 1593 DD. If DD accumulations in your area are close to 1593 DD, closely monitor plants infested with pine needle scale. If you have active crawlers now is the optimal time to treat. Pine needle scale settled crawler (1st instar) upper left corner; adult scales showing white wax covers. Photo: Ohio State University Christmas Tree Fact Sheet Control: Many lady beetles and parasitic wasps feed on this pest; therefore, careful monitoring for predators and parasitoids, as well as using pesticides with little effect on beneficials, can allow biological control to suppress the population. If control is warranted, use a summer rate of horticultural oil or an insect growth regulator (IGR) such as Distance or Talus to target crawlers. White Prunicola Scale (WPS), Pseudaulacaspis prunicola (armored scale) Monitoring WPS populations on Prunus subhirtella Autumnalis in Laytonsville, MD on Thursday, July 16 for their second generation we found active crawlers! As of July 16 the degree day (DD) readings in Laytonsville were 1906 DD. The trees we are monitoring have many scale covers, but low numbers of live scales. If the DD accumulations in your area are near 1906 DD you should closely monitor plants infested with WPS. If crawlers are active and abundant, it is time to treat. We will continue to monitor for the 3rd generation of crawlers which should be about early September and 3043 DD. Monitoring: Closely examine preferred host plants for WPS, Prunus species (especially Japanese flowering cherry), Ligustrum spp. (privet), Euonymus spp., and Syringa spp. (lilac). WPS has 3 generations per year; the second generation crawlers are active now. You are looking for the white male and female covers on the bark of branches and trunks. The adult female has a distinctive fried egg appearance and clusters of males give the bark a fluffy appearance. Crawlers (1 st instar) are salmon-colored. Note: white peach scale looks very similar to white prunicola scale but they have different host plants. Control: When crawlers are out, apply pyriproxyfen (Distance) or buprofezin (Talus) mixed with 0.5-1% horticultural oil for control Obscure Scale, Melanaspis obscura Marie Rojas, IPM Scout, is finding crawlers of obscure scale on July 15 in Frederick County. Marie noted that the coolest thing was that the twicestabbed lady beetles were all over the trunks of the affected scarlet oaks! Twice-stabbed lady bird beetles are arriving as obscure scale crawler activity is starting Photo: Marie Rojas, IPM Scout 6 The second generation of white prunicola scale crawlers are active now

7 Great Golden Digger Wasp, Sphex ichneumoneus Nancy Woods, Montgomery County Parks, found a female great golden digger wasp that caught a katydid to take back to provide food for the developing larvae. She noted that it filled five holes with katydids. A female cicada killer has a katydid to feed her young Photos: Nancy Woods, Montgomery County Parks Beneficial of the Week By: Paula Shrewsbury, UMD Predators in the night: Snowy tree crickets This past week I have been out at night searching plants for insects. I was doing this for research purposes, but it is also a good form of entertainment! Just be sure to protect against those blood sucking mosquitoes. At night there is a very different complex of predators and other insects that are active than during the day. As I was on my night hunt I came across several tree crickets. Tree crickets are omnivores and feed on both plants (herbivores) and other insects (predators). There are many species of tree crickets, Oecanthus spp. (Orthoptera: Gryllidae) and most have an overall similar appearance. The most common species I have seen is the snowy tree cricket, Oecanthus fultoni, which has an Snowy white tree crickets are pale green to almost white crickets that hunt for their food at night Photo: M. Raupp, UMD 7

8 elongate, narrow body (about mm long) and is pale green in color with orange on the head. The antennae and legs are long and thin and the legs are musculature for jumping. Snowy tree crickets are found throughout the U.S., active July through October, have one generation per year, and are active at night (nocturnal). Common habitat for snowy tree crickets is trees, shrubs and vines, especially around houses and wood edges. Tree crickets can feed on the foliage of plants but usually not to the extent to warrant control. The defoliation appears as somewhat ragged or having a shredded appearance. As predators, snowy tree crickets feed on a variety of insects, mostly insects within the order Hemiptera (ex. aphids, scales, psyllids). Tree crickets have one generation per year. Eggs are laid in the fall in a line of small holes drilled in the bark of branches. In the spring eggs hatch. As nymphs develop through the season they undergo about 12 molts and reach adulthood around mid-summer (now). In the insect world, it is often the female that chooses whether to accept a male for mating or not which has resulted in the evolution of various measures that males use to attract females. For tree crickets, males do not only have to produce a really great song, but they also have courtship feeding. Shortly after copulation the male produces a fluid from a gland located in the thorax between the wings. The female consumes this fluid. The fluid provides nutrition to the female that increases the likelihood of successful reproduction. Tree crickets communicate through sound, much like cicadas. There is a lot known about the snowy tree cricket song. Only males produce the calling song, not females. Males use a stridulatory file (a row of little teeth-like structures on their wings) that they rub together to make their chirp (or trill) sound. The chirp is somewhat long and continuous. Females have a tympanum (for hearing) the male calls. Tree crickets have a system referred to as sender-receiver matching. A male tree cricket produces a mating call in a specific ranch of frequencies unique to that species. Females of that species pick up the call of males only from their species, not other species. One of the more interesting and fun facts about these crickets, is that they are sometimes referred to as thermometer crickets because the rate of their chirps correlates with temperature. You can actually use snowy tree crickets to estimate the temperature. In the eastern U.S. to determine Fahrenheit temperature, count the number of chirps in 13 seconds and add 40 to that number and that should be the ambient temperature. You can do an internet search to learn to recognize and distinguish the sound of snowy tree cricket chirping from other insect and animal sounds (go to: and click on the video). I suggest on one of these warm summer nights you get a flashlight and go outside to see and hear the nocturnal world of insects! Weed of the Week By: Chuck Schuster Bermudagrass is currently on the minds of many. The abundant moisture has made it possible for all turfgrass to continue to grow prolifically. Bermudagrass is showing up in many landscapes and when a close examination of turf is done, it is often found. It is out, though some feel the temperatures are not warm enough. Bermudagrass, also called wiregrass, Cynodon dactylon, is a warm season perennial grass found throughout this region. The roots are fibrous, coming from nodes of both rhizomes and stolons. The leaf blades are often hairy on the upper side, two to six inches in length, and one eighth to one quarter inches Bermudagrass is doing well with the wide. This perennial can be spread by stolons, thus making mechanical recent rains removal difficult. Bermudagrass tolerates a wide range of moisture and Photo: Virginia Tech Weed ID Guide fertility ranges and adapts to most conditions. While bermudagrass is used in certain lawn or sports field settings it will spread into landscape beds and can be difficult to control. 8

9 The flowers of bermudagrass consist of three to seven fingerlike projections spikes that come from a single point. The individual spikes are flat and are one to three inches in length. A similar weed to bermudagrass is nimblewill. You can distinguish the two by reviewing the ligule; on bermudagrass it is hairy and on nimblewill it is membranous. Control of bermudagrass in a landscape setting can be achieved with the application of post emergent, non selective herbicides that contain glyphosate, and clethodim (Envoy, Prism), (selective on grasses only) and may take more than one application to control. Late summer treatment provides better long term control of this difficult to control weed. In nursery only settings sethoxydim (Poast) can be used. Remember that it is a warm season grass; active growth is needed for effective control and will occur later than cool season weeds. Control of bermudagrass in cool season turf (fescue, perennial ryegrass, Kentucky bluegrass can be achieved using fenoxaprop-ethyl (Acclaim Extra 0.57 EC). Repeated applications will be required every four weeks. Ethofumesate (Prograss 1.5 EC) can also be used but can cause injury to some cool season turf grasses (Kentucky bluegrass will require reduced rates, and hard fescue or other fine fescue turf grasses are not labeled at all). This will also require repeated applications every three to four weeks. A new product topramezone (Pylex) can be useful for control of Bermuda in cool season turf. In one option three applications can be made using the 1.5 fluid ounce per acre rate with tricloopyr at 32 ounces per acre for the first two applications, and 1.0 fluid ounce of topramezone on the last application with each application being 21 to 28 days apart has been very effective. The addition of a crop oil is recommended. As with any program to reduce or eliminate Bermudagrass reseeding open areas is important. Plant of the Week By: Ginny Rosenkranz Quercus robur fastigiata or Fastigiata English oak is a deciduous tree with dark green leaves in the summer that mature in the fall to golden yellow or copper and then fade to brown. Leaves are similar in shape to the American white oak (Q. alba) having bluntly rounded lobes and rounded sinuses, but are smaller, growing only 2-4 wide and 4-8 long and the sinuses are not as deep. The brown leaves will persist on the trees all winter, adding color and texture during the coldest months. The silhouette of Fastigiata English oak is densely upright in an elongated oval with a short trunk. The dark brown bark also adds winter interest with its deep ridges. Growing feet tall, they do best in full sun and are tolerant of salt, pollution and once established, drought. Soil ph should be slightly acidic to slightly alkaline, and moist but well drained soils that include sand, loam and clay. Fastigiata English oak is winter hardy in USDA zones 4-8 and fits into very narrow landscapes as street trees, specimen trees or even screens. New cultivars include Skyrocket, Koster and Regal Prince which are all more powdery mildew resistant. Diseases include powdery mildew, oak wilt, anthracnose, oak leaf blister and leaf spots. Insect pests include gypsy moths, scales, borers and galls. 9

10 Phenology PLANT PLANT STAGE (Bud with color, LOCATION First bloom, Full bloom, First leaf) Hibiscus moscheutos First bloom July 14 (Ellicott City) Degree Days (As of July 16) 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 use a base temperature of 50 F, a start date of January 1st, and the date of monitoring as the end date. New and Alternative Crops for Greenhouse and Nursery Growers August (8:00 a.m. - 3:15 p.m.) Location: Brookside Gardens, Wheaton, MD Native plants: How to grow in the greenhouse from seed and cuttings. Dr. Sara Tangren, University of Maryland Extension, HGIC Producing cut flowers and vegetables using hydroponics from a working greenhouse operation. Matthew Bauer, Flowers by Bauer, Harford County, MD New tissue culture plants for greenhouse production. Heather McDermott, AgriStarts Tropicals, Natives, Edibles, and More, Apopka, FL Hops as an alternative crops. Tom Barse, Stillpoint Farm Ginseng: Is it green gold? Dr. Marla McIntosh, University of Maryland Hydroponic fertility. Cari Peters, Peters Lab, PA Growing native annuals and perennials for marketing as pollinator plants and to benefit beneficial insects and mites. Dr. Sara Tangren, and Stanton Gill, University of Maryland Extension Tour of Brookside Production Facility. Joe Kraut, Head Grower, Brookside Gardens To register: 10

11 Upcoming Conferences: Alternative Greenhouse Crops Conference August 5, 2015 Location: Brookside Gardens, Wheaton, MD MAC-ISA Arborist Certification Course August 17-19, 2015 Location: NVCC Loudoun Campus, Sterling, VA FALCAN Truck and Safety Seminar August 19, 2015 Location: Urban Fire Hall, Urbana, MD LCA Hands-on Training Seminar September 16, 2015 Location: Johns Hopkins Univesity, Mongomery County Campus Interiorscape Conference October 1, 2015 Location: Rawlings Conservatory, Baltimore, MD Community Forestry Workshop October 2, 2015 Location: Carroll Community College, Westminster, MD 4 th Annual TreesMatter Symposium November 4, 2015 Location: Silver Spring Civic Center, Silver Spring, MD CONTRIBUTORS: Stanton Gill Extension Specialist sgill@umd.edu (cell) 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 clement@umd.edu Andrew Ristvey Extension Specialist aristvey@umd.edu Ginny Rosenkranz Extension Educator rosnkrnz@umd.edu Nancy Harding Faculty Research Assistant 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.