Pam Bennett, Barb Bloetscher, Joe Boggs, Jim Chatfield, Erik Draper, Dave Dyke, Dave Goerig, Tim Malinich, Jane Martin, Hannah Mathers, Pam Sherratt, Amy Stone, and Curtis Young
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September 15, 2005
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This is the Twenty-fourth 2005 edition of the Buckeye Yard and Garden Line (BYGL).
BYGL is developed from a Tuesday morning conference call of Extension
agents, specialists and other contributors in Ohio.
BYGL is also made available on the Internet from the Ohio State University
Horticulture and Crop Science (HCS) in Virtual Perspective website
(http://bygl.osu.edu). Additional fact sheet information on any of
these articles may be found through the OSU fact sheet database (http://plantfacts.osu.edu).
BYGL is a service of OSU Extension and is aided by major support
from the Ohio Nursery and Landscape Association (ONLA), with additional
funding from the Ohio Chapter of the International Society of Arboriculture
(ISA) to the OSU Extension Nursery Landscape, and Turf Team (ENLTT).
Participants in the September 13, 2005 conference included: Pam Bennett (Clark); Barb Bloetscher (C. Wayne Ellett Plant and Pest Diagnostic Clinic-CWEPPDC) Joe Boggs (Hamilton/Piketon); Dave Dyke (Hamilton) Dave Goerig (Mahoning); Curtis Young (Allen); and Randy Zondag (Lake)..
Additional factsheet information on any of these articles may be found
through the OSU Factsheet Database (http://plantfacts.ohio-state.edu/)
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WEATHER WATCH
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BYGLers reported that it is still pretty dry for most of the state. Rain is needed in many areas for newly seeded turf as well as other plants still struggling from this past summer's stresses.
Following is the weather summary from September 6 - 12, 2005:
| Weather Station |
Region of Ohio |
Ave. High Temp F | Ave. Low Temp F | Ave. Temp F | Normal Ave. Temp F | Total Precip " | Normal Precip " | | Perry |
NE |
80 |
59.2 |
N/A
|
N/A |
2.01 |
N/A | | Hoytville |
NW |
86.5 |
55.2 |
70.2 |
66.5 |
0.16 |
0.48 |
| Columbus |
Central |
86.4 |
57.6 |
71.7 |
68.7 |
0.00 |
0.49 |
| Miami |
SW |
86.7 |
60.3 |
72.4 |
68.4 |
0.02 |
0.48 |
| Jackson |
South |
85.5 |
51.4 |
67.2 |
67.9 |
0.00 |
0.54 |
For a link to the OARDC Weather Stations, check out: http://www.oardc.ohio-state.edu/centernet/weather.htm
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HORT SHORTS
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PLANTS OF THE WEEK
Read all about perennials and landscape trees and shrubs in the new publications "Perennial Plants for Ohio" and "Landscape Plants for Ohio" published by the Ohio Nursery & Landscape Association (ONLA). The descriptions and photographs of plants were provided for this new publication by the OSU ENLT Team along with other industry plant lovers. These full-color publications are available at Buckeyegardening.com for $5.00. Click on "garden store" and then "onla plant guides." ONLA members can purchase these in quantities at a reduced price at onla.org
* PERENNIAL OF THE WEEK - Aster spp. - This diverse genus contains over 600 species, some which are blooming in central Ohio at this time. Many of the species are native to the Americas. The plants thrive in full sun and bear daisy-like flowers in late summer. Many varieties perform better if pinched back in the spring in order to encourage branching and a more compact plant as well as more abundant flowering. Depending upon the cultivar, they can be used in the perennial border, rock garden, and woodland and meadow areas.
Try some of the newer cultivars such as 'Alert' with its compact 8 - 10" tall plant and purplish flowers or one of the 'Woods' series (blues and purples) with the compact 12 - 18" growth that flowers from September to late October.
*WOODY PLANT OF THE WEEK. Clematis ternifolia - sweet autumn clematis. When in full bloom, this plant literally takes your breath away! It has masses of tiny, creamy-white flowers from August to October. The heady, heavy fragrance attracts bees and can be a nuisance if planted . Keep this in mind when selecting a planting site. The plant itself is a prolific grower and requires a strong support as it can get quite heavy.
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BUG BYTES
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ANTLIONS "ROAR."
The recurring dry conditions that have plagued much of Ohio this season have provided ideal environments for antlions, or DOODLEBUGS. Indeed, Joe Boggs reported that the small, funnel-shaped pits constructed by these intriguing predators are a common sight in dry, powdery soil beneath plants or near building foundations.
Antlions are in the insect order, Neuroptera (neuro = nerve, optera = wing). Adults resemble damselflies. The unusual larvae have long sickle-like mandibles, a trait shared with other Neuropteran predators, such as aphidlions. Some antlions lie and wait for prey on or just below the surface of the ground, or they give chase across the surface of the ground. However, the species that Joe reported employs the ultimate tool in ambush ingenuity a pitfall trap.
Pitfall-type antlions construct their trap by moving backwards in loose, dry soil in a spiral pattern, and using their long mandibles like a shovel to throw soil particles out of the gradually deepening crater. A conical pit that is 3/4" - 2" wide and around 1 /2" deep is created. The antlion positions itself at the bottom of the pit with only its mandibles exposed, awaiting its prey.
When a hapless victim blunders into the trap, the loose dry soil particles provide no traction for escape. As the trapped victim struggles, the antlion lunges with snapping mandibles to seize its quarry. The sharp-pointed tips of the mandibles pierce the victims exoskeleton, allowing the essence-of-insect to drain into the antlion's mouth. It is a dramatic scene.
These ant antagonists have long been recognized for their instructional (entertainment?) value. Joe Boggs noted that in past years, he has collected the larvae and housed them in a sand-filled aquarium; a kind of anti-ant farm. This provided a fascinating teaching tool for demonstrating the diversity in insect predatory techniques, and the drama in a bugs life.
 
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HORSEHAIR WORMS SQUIRM
Joe Boggs also reported receiving a phone call from a homeowner concerned about squirming masses of long, thin, white worm-like creatures appearing in a bird bath. The homeowner called to ask what these creatures are and if they posed a threat to bathing birds. In an interesting connection of observations, the homeowner also noted that her landscape was heavily infested with grasshoppers.
The writhing critters are a type of roundworm called horsehair worms. They are also called cabbagehair worms, Gordiid, or Gordian worms, and they belong to a group of organisms called Nematomorphora. The horsehair name came from early speculations that these worms arise through "spontaneous generation" from horse hairs. Their common occurrence in horse watering troughs provided support for this erroneous belief. The common name of Gordian worms comes from their tendency to twist their long (4" to14") thin bodies into loose, knot-like balls that may resemble the enigmatic "Gordian knot" of Greek legend.
The immature or juvenile stage of horsehair worms are considered beneficial since they live as internal parasites of a wide range of arthropods including: centipedes; millipedes; grasshoppers; crickets; cockroaches; and beetles. The juveniles lack a mouth and digestive system. But since they live inside the hosts body cavity, swimming around in the nutrient rich blood (hemolymph) of the host, nutrients can be directly absorbed through the worms body wall. Once the worms are nearly mature, they must induce their host to take them to water so the adult worms can emerge into the aquatic environment. It is speculated that the heavy absorption of moisture by the nearly mature juveniles causes the host to become thirsty. Thus, grasshoppers will swan dive into bird baths!
The adult worms that emerge from the submerged host are the horsehair worms. They can live for six months in high moisture environments and they may be found in pools of water, in decaying vegetation, and on lower portions of plants, but they do not feed. Eventually, they produce eggs which hatch into larvae that encyst on vegetation. Once these encysted larvae are eaten by an arthropod, the long, twisting life cycle starts all over again.
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BAGWORMS NEARLY IN THE BAG
Bagworm (Thyridopteryx ephemeraeformis) activity is nearly done for 2005. Both Joe Boggs and Curtis Young reported observing male bagworm moths emerging from their summer homes. Only the male bagworm completes metamorphosis into moth stage capable of flight. The adult male bagworm moths have clear wings that are not covered with scales, their bodies are loosely covered with black scales giving them a scruffy appearance, and are about 1" in length. Female bagworms are flightless, worm-like adults that normally do not leave their bags that they constructed while they were caterpillars. They are literally creamy white sacs of eggs a little over an inch in length.
The males will search out the females in their bags. They fly to the females and mate them through the bottom of the bag. After mating with the female, the male flies off in search of a new conquest. The males live for a short time, mate as often as they can, then die. Once the female is mated, she begins laying her eggs into her pupal skin. While laying her eggs, hairs (scales) off of her body are packed around the eggs. Once she finishes laying her eggs, she is spent and shortly thereafter, she dies. Bagworms remain as eggs till the following season.
Management of bagworms is limited to hand-picking the bags off of the host plants and destroying them. The next opportunity to manage bagworms with insecticides will be next June (2006) after the eggs hatch and the new caterpillars begin feeding again.
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SOOTHSAYERS HANGING OUT HIGH ON WEEDS
The soothsayers of which we speak are not loopy prophets smoking "wacky tobaccy," but PRAYING MANTIDS (Order: Mantodea). It is the time of the season that the mantids have reached the adult stage and can be found fairly easily on many shrubs and weeds, especially around old fields and windbreaks. Mantids are large insects some being 5-6" in length. Females tend to be larger than males and their abdomens are swollen with eggs to be laid. The mantids range in color from all brown to green with brown wings to solid green. Their front legs are highly modified grabbing and holding prey. Their common name is derived from the position they lie in waiting for prey to stray within striking distance. They appear to be praying.
There are only a few species that exist in Ohio and the most common species are the Carolina mantid, Stagmomantis carolina, the European mantid, Mantis religiosa, and the Chinese mantid, Tenodera aridifolia sinensis. The Carolina mantid is the smallest of the three and the Chinese mantid is the largest. Mantids are plentifully in numbers and are not an endangered species nor protected by Ohio or federal law.
Mantids overwinter in the egg stage. The female mantid lays her eggs on stems and twigs of shrubs and stems of weeds. The eggs are contained in a styrofoam-like egg case secreted by the female as she lays the eggs.
Mantids are highly touted as biological control agents, however there is usually not enough of them in one particular area to keep damaging insect populations in check. Additionally, mantids do not discriminate between destructive insects and beneficial insects. They can in some instances be quite destructive themselves around a beehive where they may have a real feast on honeybees going in and out of the hive. The females can also be rather ruthless toward their mates and consume their mate right after mating or while still in the act.
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THE ATTACK OF THE GRASSHOPPERS
Pam Bennett, Joe Boggs and Curtis Young all reported observing high populations of grasshoppers in all kinds of environments including natural areas, backyard gardens and perennial gardens. Joe Boggs felt a little like Tippi Hedren in the Alfred Hitchcock thrill, "The Birds" (circa 1963), when he looked up from his gardening to see no less than ten of the little jumpers lined up on top of the fence staring at him with their steely gaze. He almost ran to the house to nail himself in.
Curtis reports walking a primitive trail through a nature preserve where hundreds of grasshoppers when jumping ahead of him with each step he took. On a more serious note, Pam is having trouble with the grasshoppers damaging ornamental grasses, irises and other perennials in their demonstration gardens in Clark County.
Grasshopper populations fluctuate in cycles. High or very high populations may be present for two to four years followed by low to moderate populations for several years. Even when overall populations are relatively low, grasshoppers in and around the garden can be a nuisance. In outbreak years, however, grasshoppers can destroy unprotected gardens and threaten small trees and shrubs.
Two grasshopper species - the differential (Melanoplus differentialis) and redlegged (Melanoplus femurrubrum) grasshoppers - cause most damage in yards and gardens. The potential for grasshopper damage increases as summer progresses. Adults will be more likely to move into yards and gardens in July, August and September. Severe problems may arise when adjacent agricultural crops or grasslands mature or are harvested and grasshoppers move to find new food sources. Defoliation is the primary injury to plants, but fruit and ripening kernels of grain also will serve as food sources.
Grasshoppers show a preference for flowers and some garden vegetables (e.g. lettuce, beans, sweet corn), but when populations are high they will feed on nearly all garden vegetables, as well as trees and shrubs. Small trees and shrubs will be the most seriously affected.
Grasshoppers will feed on just about anything as long as they do not detect a feeding deterrent. Reports are common of grasshoppers eating paper, paint, window screen, window or caulking, fenceposts, hoe handles, etc. during grasshopper outbreak periods.
Heavy infestations of grasshoppers may require chemical treatment to reduce or prevent serious damage to sensitive plants. For a list of effective materials and control timing consult OSU Extension Bulletin 504 titled, "Insect and Mite Control on Woody Ornamentals and Herbaceous Perennials" [http://ohioline.osu.edu/b504/index.html].
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MALB ON THE MOVE
Curtis Young warned again that MULTI COLORED ASIAN LADY BEETLE (MALB), have become abundant in soybean fields and are already beginning to move to adjacent areas. He projected that they may become a menace to homes in areas where the soybeans were infested with the soybean aphid, which consequently attracted MALBs as well as other lady beetles species. MALBs have been especially useful in controlling the soybean aphid as both the larvae and adults devour aphids each day.
Unlike the native species of lady beetle however, which overwinter in leaf litter, MALBs prefer structures which closely resemble the tree covered mountains of their native country, Asia. Structures which cast strong vertical contrasts on the south or west side in the afternoons are most susceptible to the barrage of MALBs seeking overwintering sites. Several years ago, entomologists devised a formula to predict MALB migration, enabling people to treat buildings preventively if necessary. In Ohio, complaints of the lady beetles moving into homes increases the 1st and 2nd week of October.
To prevent MALBs as well as other fall invading insects and spiders from entering buildings, seal and caulk around doors, windows, vents, ducts, and conduits in exterior walls, like wise, seal soffit and fascia trim around the roofline. Several pyrethroids are labeled to control household invaders, including bifenthrin (Talstar) and cyfluthrin (Tempo). Some formulations of permethrin are also labeled. Products are available for homeowner use as well as Pesticide Operators who are licensed for perimeter pesticide applications.
To keep ground beetles, sowbugs, pillbugs and millipedes from entering, pull mulch at least 6-8' away from the perimeter of the building and eliminate any source of moisture, such as a dripping hose spigot, leaky down spout or poorly graded soil. Removing moisture, food (organic matter), and places for the creature to hide will reduce the populations residing near the home. Redirect outdoor lights so that they shine away from buildings and/or use yellow sodium bulbs. These non chemical measures will reduce the number of insects and therefore reduce the primary food source for the spiders nearby. For more information, refer to the OSU HYG Factsheet 2060 "Spiders In and Around the Home" and HYG 1030 "Multi-colored Asian Lady Beetles".
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DISEASE DIGEST
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BOTRYOSPHAERIA CANKER ON ASH
Participants at this week's BYGLive! in Cincinnati observed the effects of Botryosphaeria canker on white ash. In its mildest form, the disease only causes twig and branch cankers. However, when infected trees are stressed, symptoms may include branch dieback and leaf flagging. As noted in last week's BYGL, leaf flagging has been observed in recent weeks throughout western and southwestern Ohio.
BYGLive! participants observed varying degrees of branch dieback and leaf flagging. Most flagging occurred on the lower portion of the trees, although some sporadic flagging was seen throughout the canopies. Close inspection of twigs and branches revealed the stem cankers. The cankers appeared as swollen, nodule-like growths on twigs, or bulging growths on branches. The bark on these growths was roughened and deeply etched by longitudinal slits. The 1 /2" - 1 1/4" long slits superficially resembled hail damage or insect egg-laying sites. Slits on older cankers had lengthened and deepened exposing the xylem.
There are no recommended treatments for this disease, other than to apply good plant health management practices. The fungus may have entered the affected trees years earlier, but the disease behaves as a "latent infection." The fungus is in the tree, but defense mechanisms normally keep it from producing symptoms more severe than mild cankering. However, when the tree is stressed, the defense mechanisms are overwhelmed and branch dieback occurs. The best way to avoid branch dieback and leaf flagging is to avoid plant stress. The occurrence of these symptoms this season is being associated with drought stress. Affected trees should be watered. As with dealing with other stress-related tree problems, reducing the cause of the stress will provide the best support for a recovery from this disease.
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TURF TIPS
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RUST RETURNS
The perennial orange spotted turfgrass, recognized as rust disease, caused by Puccinia spp. has become prevalent around Ohio, especially in the areas scourged by drought this summer. Callers describe shoes, clothes, and dogs feet covered with an orange or rusty dust after walking across the grass, especially in the morning when the turfgrass is moist with dew.
Upon closer inspection, the lower side of the leaf blades have a series of pustules, or masses of spores, that run the length of the leaf blade. The pustules begin as small, yellow dots, then with dew and splashing water, increase in size and change from an orangey yellow to orange-brown upon maturity. Leaves covered with these pustules wither and die, causing the stand of turfgrass to gradually thin.
Rust is favored by warm summer days with cool nights and heavy dew accumulation in the mornings, or light, frequent irrigation that keep grass blades wet. When the environment favors this fungus, susceptible varieties of Kentucky bluegrass and perennial ryegrass can thin and appear brown, although it normally does not kill the turfgrass roots.
To reduce the severity of rust, irrigate lightly in the morning to wash the spores off the leaves and water deeply if the soil is dry, to prevent the turfgrass from wilting. Apply a balanced fertilizer containing 30-50% slow release forms of nitrogen to encourage new growth. Core aerate if necessary, to reduce soil compaction, and keep as much traffic off the turfgrass as possible. For more details on rust, refer to OSU Bulletin L-187, Management of Turfgrass Pests, Weeds, Diseases, and Insects.
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INDUSTRY INSIGHT
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TREATMENT FOR EMERALD ASH BORER IN THE NEWS
Several BYGLers reported receiving questions from Ohioans that were generated by a recent emerald ash borer (Agrilus planipennis) (EAB) press release recommending insecticide treatments for EAB. The press release was not generated by the Ohio Department of Agriculture, or The Ohio State University. It was generated in Michigan where many people are currently living with this non-native pest. Unfortunately, some versions of the press release that were printed in Ohio newspapers appeared to indicate the Michigan recommendations applied to all states, including Ohio.
Why do insecticide recommendations for EAB that are made for Michigan not apply to Ohio? The answer is location, location, location!
First, EAB is an exotic insect that is regulated by USDA-APHIS, and it is subject to eradication. If an infested tree is discovered in Ohio, it will be removed and destroyed along with all ash trees within a 1 /2 mile radius of the infested tree. This is done in Ohio because female EABs are mobile and can lay eggs on many trees. However, infested trees do not show any external symptoms during the first year of the infestation. Ash trees are removed within a half-mile radius of a tree that is known to be infested to insure the entire infestation is eradicated. The insect is so wide spread in southeast Michigan that no eradication program is being conducted; it is simply too late.
Second, while there are insecticides that provide some suppression of EAB, none are consistently 100% effective. This is why the ODA does not recognize insecticide treatments as part of the eradication program in Ohio. Halting the spread of EAB in Ohio requires the use of eradication tools that are 100% effective there is no margin for error. Therefore, even if an insecticide treatment history is well documented, the treated ash tree(s) will not be spared from the Ohio eradication project.
The situation is entirely different in southeast Michigan. There are so many infested ash trees that an ash tree removal program aimed at eradicating EAB would have little chance of success. It would be like fighting a forest fire by starting in the middle of the conflagration and working towards the outer edges. It's best to start at the edges. Southeast Michigan is in the middle of the EAB "fire," and Ohio is at the edge.
Property owners in southeast Michigan are financially responsible for the removal of dead trees on their property. This is not part of an EAB eradication program. The dead trees are removed by the homeowner to reduce liability issues presented by the dead trees, not from EAB. Consequently, some are opting for preventative insecticide treatments, with mixed results.
For all of these reasons, the OSU ENLT Team, in consultation with the Ohio Department of Agriculture (ODA) has developed the following recommendation for Ohio:
Currently, we recommend that ash trees in Ohio not be treated with insecticides for emerald ash borer, even if the tree is in the immediate vicinity of a known infestation.
For further information, please refer to Ohio Emerald Ash Borer FactSheet, "Should I Treat My Trees for Emerald Ash Borer" at the site below.
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COMING ATTRACTIONS
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FARM SCIENCE REVIEW
The Farm Science Review (FSR) is held annually at the Molly Caren Agricultural Center in London, Ohio. This year marks the 43rd year of the event. If you are engaged in an agricultural related occupation, this Nationally recognized Ag Show is something to experience. Once there, you will experience 600 plus exhibitors displaying their wares over 83 acres. Look for 750 plus acres of field demonstrations and much more on the 2,100 acre facility. Think its all about production agriculture, well look a little closer. On display will be over 4,000 different equipment lines. Everything from irrigation to portable generators to landscape equipment will be there to demonstrate.
FSR only runs for three days; Tuesday, September 20 and Wednesday, September 21 from 8:00a.m.till 5:00p.m., and Thursday, September 22, from 8:00a.m.till 4:00p.m.. Advance tickets are $5.00 each and $8.00 at the gate. Children five and under get in free! Tickets are available from OSU Extension offices and local agribusinesses.
OSU Extension will be there as well offering educational programs covering the latest research and field trial results. Look for the Extension Nursery Landscape turf team members giving presentations at the Gwynne Conservation Area, and The Utzinger Garden Area, and OSU Central. FSR is sponsored by the Ohio State University and related Colleges. For more information click on the website below.
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OSU/ONLA NURSERY AND LANDSCAPE RESEARCH DAY
Catch up on the latest and greatest research at OSU by attending this program on September 22 at the Waterman Farm on the Columbus campus. The program starts at noon with lunch (and brief presentations) and continues until 3:45 p.m. Presenters include Dr. Hannah Mathers, Dr. Dan Herms, Michele Bigger, Alejandra Acuna, Enrico Bonello, Alieta Eyles, Don Cipollini, Nathan Kleczewski, Randy Zondag, Heping Zhu, Charles Krause, Mike Redding, Luke Case, and Richard Rathjens. The afternoon includes tours of the Waterman and Howlett Nursery Trials. There is NO COST; contact Dr. Mathers at 614-247-6195 or Luke Case at 614-292-0209 to register.
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BYGLOSOPHY
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"Nature will bear the closest inspection. She invites us to lay our eye level with her smallest leaf, and take an insect view of its plain". - Henry David Thoreau, Naturalist and Author. 1817-1862
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