BYGL Weekly News for October 15, 2018
The following articles were compiled during the last 7 days by members of the Extension, Nursery, Landscape, Turf (ENLT) team to benefit those who are managing a commercial nursery, garden center, or landscape business or someone who just wants to keep their yard looking good all summer. Access the BYGL website for additional information on other seasonal topics at: http://bygl.osu.edu
For more pictures and information, click on the article titles. To contact the authors, click on their names.
Get Ready for a Little Breaking and Entering
Authors Joe Boggs
Published on October 11, 2018
Our drop in temperatures throughout Ohio will no doubt convince fall home invading insects that it’s time to seek winter quarters. These unwelcomed guests typically include Boxelder Bugs (Boisea trivittatus); Western Conifer Seed Bugs (Leptoglossus occidentalis); Magnolia Seed Bugs (Leptoglossus fulvicornis); Multicolored Asian Lady Beetles (Harmonia axyridis); and the most notorious of all, Brown Marmorated Stink Bugs (Halyomorpha halys).
These home invaders have several things in common. First, their populations may vary considerably even across relatively short distances. Some homes may be inundated while those located just a few miles away remain free of insect marauders.
Even more challenging, late-season outdoor populations are not always a reliable predictor of indoor excursions. Just because you didn’t see them in September doesn’t mean you won’t see them sitting next to you on your sofa in November.
A Series of Unfortunate Events
The second thing these home invaders have in common is their “cold-blooded” physiology meaning the speed of their metabolism is mostly governed by ambient temperature; the higher the temperature, the faster their metabolism, and the faster they “burn” fat. Yes, insects have fat, but it’s confined by their hard exoskeletons so they don’t suffer ever-expanding waistlines.
These insects feed voraciously in late summer to accumulate fat. They then seek sheltered locations in the fall where cool temperatures slow their metabolism during the winter so they will not exhaust their stored fat reserves. This survival strategy keeps them alive since there is nothing for them to eat throughout the winter.
The insects are attracted to the solar heat radiating from southern or western facing roofs and outside walls as well as the warmth radiating from within. This can lead them into attics, outside wall voids, and spaces around door jams and window frames that make perfect overwintering sites. They stand a good chance of surviving the winter as long as they remain in these cool, protected sites.
However, sometimes they make a terrible error; for both the insect and a homeowner. Instead of staying put, they continue to follow the heat gradient into homes. This is accidental and disastrous for the insects because the high indoor temperatures cause them to burn through their fat reserves and starve to death. And, they do not go gentle into that good night! Starving brown marmorated stink bugs and multicolored Asian lady beetles commonly take flight to buzz-bomb astonished homeowners and terrified pets.
The Best Defense is a Good Offense
The best defense against home invaders buzzing or lumbering around inside a home is to prevent them from entering in the first place. Although there are effective indoor marmorated stink bug traps, they shouldn’t be used in place of sealing openings that allow the bugs to enter the home. An ounce of prevention is worth a pound of bugs.
Large openings created by the loss of old caulking around window frames or door jams provide easy access into homes. Such openings should be sealed using a good quality flexible caulk or insulating foam sealant for large openings.
Poorly attached home siding and rips in window screens also provide an open invitation. The same is true of worn-out exterior door sweeps including doors leading into attached garages; they may as well have an “enter here” sign hanging on them. Venture into the attic to look for unprotected vents, such as bathroom and kitchen vents, or unscreened attic vents. While in the attic, look for openings around soffits. Both lady beetles and stink bugs commonly crawl upwards when they land on outside walls; gaps created by loose-fitting soffits are gateways into home attics.
Handle with Care
Insects that find their way into a home should be dealt with carefully. Swatting or otherwise smashing these insects can cause more damage than leaving them alone since fluids inside their bodies can leave permanent stains on furniture, carpets, and walls. Also, mashing multicolored Asian lady beetles and brown marmorated stink bugs can release a lingering eau de bug; lady beetles have stinky blood and stink bugs are called stink bugs for a reason!
Vacuum cleaners present their own set of risks. A “direct-fan” type of vacuum cleaner should never be used. Passing the refuse through an impeller will create a horrifying bug-blender! Even a “fan-bypass” type (e.g. Shop-Vac) with the refuse bypassing the impeller can develop a distinctive scent if used on stink bugs because the bugs will release their defense odor in response to swirling around inside the vacuum tank.
However, fragrant misadventures with vacuum cleaners can be minimized with a slight modification involving using a nylon ankle sock. The method is clearly described in the OSU Factsheet titled, Multicolored Asian Lady Beetle (see “More Information” below).
Small numbers of home invaders can be scooped-up and discarded by constructing a simple but effective “bug collector” using a plastic pint water bottle. Large numbers of insects can be quickly dispatched by placing a small amount of soapy water in the bottom of the bug collector.
OSU Factsheet, Multicolored Asian Lady Beetle, ENT-44
Calico Scale Crawlers Move to Stems
Authors Joe Boggs
Published on October 11, 2018
Infestations of the non-native Calico Scale (Eulecanium cerasorum) can be difficult to detect during the growing season. However, clusters of crawlers on blackened stems coupled with dead females are key diagnostic features for spotting calico scale at this time of the year.
Calico scale is a “soft scale” meaning that female scales are protected by a soft helmet-shaped shell. This is a relatively large soft scale with mature female shells measuring about 1/4″ in diameter. The scale’s common name comes from the starkly contrasting calico pattern of black-and-white markings on the shells of live females found on the stems in the spring.
Females produce fertile eggs in late-spring to early-summer without the need for mating; there are no males. This form of reproduction without males is called parthenogenesis.
The females then die and turn orangish-brown, but they don’t disappear. The dead females may give the false impression that control efforts such as an insecticide application were effective. In fact, I’ve have received pictures in the past of calico scale females that died of natural causes being used as proof that an insecticide application was effective.
Some of the dead females will remain attached to the stems well into the fall. However, others may become detached leaving behind a distinct silvery-white deposit that starkly contrasts with black sooty molds. Indeed, if you know what to look for, you can easily spot these deposits on stems 10 – 15′ above the ground.
The 1st instar crawlers that hatch from the eggs distribute themselves among their host’s leaves where they crowd together along leaf veins and tap into phloem vessels. They remain on the leaves throughout the growing season molting into 2nd instar crawlers in mid-summer. They migrate back to stems prior to the leaves dropping in autumn and settle down for the winter. It’s a smart move; they would have a terrible experience if they remained on the shed leaves.
The overwintered crawlers molt into parthenogenetic females in the spring. There is one generation per season.
As with all soft scales, calico scale adults and crawlers feed by inserting their piercing-sucking mouthparts into phloem vessels to extract amino acids that are dissolved in the sugary plant sap. Both adults and crawlers discharge excess sap from their anus in the form of sticky, sugary “honeydew” that drips onto the leaves, stems, and branches of scale-infested trees.
Black sooty molds colonize the honeydew to produce blackened twigs, branches and trucks which is one of the most obvious symptoms of a heavy calico scale infestation. The blackening becomes particularly evident after trees shed their leaves allowing sunshine to spotlight the black fungal growth.
Calico scale can infest a wide variety of deciduous trees including buckeye, crabapple, dogwood, elm, hackberry, hawthorn, honeylocust, horse-chestnut, magnolia, maple, oak, pear, redbud, sweetgum, tuliptree, yellowwood, witchhazel, and zelkova. However, I’ve found they are particularly fond of honeylocust; it’s my “go-to” tree for looking for calico scale in an urban landscape.
There are no effective management tactics that can be applied at this time of the year to suppress a calico scale infestation. However, discovering a calico scale infestation now will give you time to plan a management strategy for next season.
As with most soft scales, calico scale is seldom a direct killer of established landscape trees. But heavily infested trees may suffer branch dieback and the accumulated stress caused by substantial sap loss coupled with other stress-producing conditions may kill trees. So, the best first step in scale management is to resolve other issues that may affect tree health.
Fall Color: It’s not just for leaves anymore!
Authors Thomas deHaas
Published on October 11, 2018
As we approach fall and its wide range of colors, we sometimes forget about other sources of color in the landscape: FRUIT!
Viburnums, Deciduous Hollies, even Dogwoods can provide fall color in the landscape. Viburnum fruit can range from almost black to purple (Viburnum dentatum)
to red, (Viburnum trilobum ‘Wentworth’) even pink (Viburnum nudum) and yellow (Viburnum dilitatum ‘Michael Dodge).
In addition, these fruits can attract wildlife to the landscape. Deciduous Holly berries, often known as winterberries can range from bright red (Ilex verticillata ‘Stoplight’) to orange and yellow (Ilex verticilatta ‘Winter Gold’). The fruit will remain after the leaves fall and until eaten by birds and wildlife. Beautyberry can provide a splash of violet-purple color (Callicarpa dichotoma ‘Issai’).
Even flowering dogwood can put on a show with its red fruit.(Cornus florida)
So as you plan for next year and what plants to consider, don’t think just about flowers or fall color. Consider the fruit.
Great Lakes Apple Crunch Day – October 11, 2018
Authors Amy Stone
Published on October 10, 2018
Thursday, October 11, 2018 is Great Lakes Apple Crunch Day. The purpose of the day is to celebrate National Farm to School Month by crunching into locally and regionally grown apples. Everyone, regardless of your age, is welcome to Crunch!
Here are some details from Wisconsin who coordinates this multi-state event.
- Location:Any site including K-12 schools, early care settings, hospitals, colleges/universities, business campuses, state agencies and other organizations across Minnesota, Wisconsin, Illinois, Indiana, Michigan and Ohio
- Details:Celebrate National Farm to School Month by crunching into apples at NOON on Thursday, October 11. Everyone is welcome to Crunch! Although we aim for a collective Crunch on October 11, you are welcome to Crunch any day or time in October that works for you.
- Join in!Last October 1,543,781 students, children, teachers, and good food supporters across the region crunched. Let’s join forces and meet the ONE MILLION CRUNCH goal again this year! Visit the Great Lakes Apple Crunch Facebook page to get updates and see photos from last year’s Crunch. You can find the page at: https://www.facebook.com/GreatLakesGreatAppleCrunch
In Ohio you can actually register a group by logging in at: https://uwmadison.co1.qualtrics.com/jfe/form/SV_e5tFJJ58wr0g3at
In addition another web-resource that is being promoted this fall is: https://ohioapples.com/ This website will connect you with local orchards. You are able to search by GPS, by county, by orchard or by keyword. There is also information about apple nutrition, recipes and information on handling and storing Ohio apples.
So whether you take a crunch tomorrow as part of a larger event, be sure to enjoy some local apples before the season disappears.
Earlier this month, I was part of a behind-the-scenes tour at a local orchard in Northwest Ohio. As part of the tour we did an apple tasting of a dozen varieties – both antique varieties and those that are newer. The owner shared with the group about their involvement in the Midwest Apple Improvement Association. To learn more about this group of growers, check out their website at: http://www.midwestapple.com/index.php
Happy National Apple Crunch Day – one day early!
Great Lakes Apple Crunch Day
Why Trees Matter – October 24, 2018
Authors Amy Stone
Published on October 10, 2018
Join us October 24, 2018 for the annual ‘Why Trees Matter Forum’ at the Miller Pavilion at Secrest Arboretum, Wooster, Ohio. We love trees – do you?
This year we welcome keynote speaker Dr. Barb Fair from North Carolina State University. There is a host of other speakers to round out the day where we get to focus on all the reasons trees matter.
You won’t want to miss out on this educational program all about trees! See you at Secrest on October 24!
Link to Registration
A Spicy Surprise
Authors Joe Boggs
Published on October 9, 2018
I received a container of ground cayenne peppers with a surprise far greater than the capsaicin kick. The product was heavily infested with cigarette beetles (Lasioderma serricorne, family Anobiidae). The homeowner noted they hadn’t used the product for some time. However, they had noticed small brown beetles buzzing around their home and collecting on their window seals.
Cigarette beetles and drugstore beetles (Stegobium paniceum, family Anobiidae) are two common “pantry pests” in Ohio. Both beetles are reddish-brown and may feed on the same products. However, cigarette beetles are more rounded in their shape and covered in long hairs giving them a somewhat fuzzy appearance (see “More Information” below).
Cigarette beetles are so-named because they were commonly found feeding on tobacco products. The beetles may also be found feeding and fouling a wide range of dried and processed products including paprika, chili powder, dried ginger, dates, raisins, dried pasta, pet foods, stored grains, cereals, and seeds of all sorts including birdseed and seeds found in dried flower arrangements.
Although their primary means of transport and spread is through infested materials, cigarette beetles also live outdoors and may find their way into homes. For this reason, purchased products cannot always be blamed with certainty as being the source of a home pantry invasion. Still, it’s a good idea for products to be used before their “sell by” date and products being held in reserve to survive a zombie apocalypse should be periodically inspected.
Outdoors, the beetles are good flyers and most active at dusk. They are attracted to light and I have found them buzzing around porch lights at night. They reverse course inside homes with the beetles flying from darkened interiors to windows. Homeowners may find a collection of dead beetle bodies on window seals which is a strong indication of a cigarette beetle infestation.
Finding cigarette beetles or any other pantry pest in a home should trigger an immediate search and destroy mission. All possible food sources throughout the home (e.g. basements, attached garages) should be opened and inspected. These beetles can spread rapidly throughout a home to produce many “satellite infestations.”
Infested products will include beetles; fuzzy, white, grub-like beetle larvae; and hardened pupal cells from which the adults emerge. Of course, cigarette beetles change both the appearance and consistency of their food as they pass it through their gut. Whether the product is a fine powder like ground cayenne peppers or large clumps like pet food or breakfast cereal, it will all get converted into sawdust-like frass (= excrement) in the end.
Infested products should be double-bagged and placed outside to await trash collection. The products should not be stored in a garage any structure attached to a home. Products that are not infested should be placed in sealed plastic containers. Plastic food storage bags should not be used because the beetles can chew through the thin plastic.
Traps are available that are baited with the female sex pheromone for the cigarette beetle, serricornin (4, 6-dimethyl-7-hydroxy-nonan-3-one). The traps only attract males and are best used for monitoring to make certain a satellite infestation isn’t missed. The traps aren’t effective enough in a home environment to eliminate an infestation.
On a final note, we discussed this infestation during our BYGL Zoom Inservice this morning and Pam Bennett (OSU Extension, Clark County) noted that finding cigarette beetles in the ground cayenne peppers should give pause to the idea that capsaicin (the “hot” in hot peppers) is a good insecticide. Indeed, the infestation provided clear evidence that some insects, like cigarette beetles, can revel in it!
Time to Clean-Up Garden Peonies
Authors Joe Boggs
Published on October 8, 2018
Peony leaf blotch disease is caused by the fungus Graphiopsis chlorocephala (formerly Cladosporium paeoniae). The fungus produces diseases with different names depending on the symptoms.
Leaf blotch occurs when infections produce large, shiny, brown or purple leaf lesions. Peony “red spot” and “measles” occur when fungal infections produce distinct red to reddish-black spots on the stems. Typically, the measles symptoms appear before the leaf blotch symptoms with the stem lesions expanding as the season progresses.
Peonies are also susceptible to a specific gray mold fungus, Botrytis paeoniae. The fungus may infect newly emerging shoots in the spring covering them in a fine, velvety gray mold. The Botrytis can also infect flower parts later in the season to produce “bud blast” with flower buds failing to open and “flower blight” with opened flowers collapsing and becoming blackened. Fungal infections can also move down the stems to produce a “shoot blight.”
Unfortunately, web searches may yield reports with images that clearly show peony leaf blotch but are mislabeled “Botrytis blight,” or images of Botrytis infections that are blamed on the leaf blotch fungus. These fungi have very different disease cycles. Of course, it’s not unusual to find both diseases on the same peony plant.
The good news is that these diseases are not considered to be killers of garden (herbaceous) peonies. Symptoms tend to escalate as the season progresses meaning plants apparently have enough time to produce and store enough carbohydrate to support regrowth the following season. However, both of these diseases can seriously detract from the aesthetic value of peonies in landscapes meaning there is value in trying to halt infections and subsequent symptoms.
The Disease Triangle illustrates the three conditions that must be met for a plant disease to develop: the pathogen must be present; the plant host must be susceptible to infection; and environmental conditions must be present that support infection and disease development. Removing only one of these conditions will prevent disease development.
Various web reports on peony leaf blotch recommend planting less susceptible varieties; however, I have found no scientific publications presenting data from plant trials that assessed disease susceptibility. There are anecdotal accounts that susceptibility varies among the different peony varieties and I’ve observed this in peony plantings. Of course, other factors may be responsible for varying levels of infections such as micro-environments acting to increase or decrease infections within the plantings.
Some disease suppression may be achieved by environmental management such as avoiding overhead irrigation. However, it’s difficult to manage natural overhead irrigation in the form of rainfall.
Suppression of the pathogen by fungicidal applications can be effective; however, success is generally problematic. Multiple applications are required over a significant portion of the growing season and heavy rainfall events can mean a shortening of the intervals between applications. Relying on fungicides alone is not likely to be successful for home gardeners and can even present a serious challenge for landscape management professionals.
Removal of the plant pathogens through sanitation is one of the effective management strategies for both of these garden peony diseases. This approach focuses on getting rid of infectious tissues that harbor the fungi throughout the growing season or over the winter.
Here are the ABCs of managing these diseases using all parts of the Disease Triangle starting this fall:
Fall (right now!):
- Cut, remove and destroy all of the top growth down to the soil line.
- Rake, remove and destroy all mulch and plant debris that was beneath the infected plants.
- Redistribute new mulch for the winter to a depth of no more than 2 – 3″. This will suppress the release of fungal spores next spring from infectious debris that may have been missed during the fall clean-up.
Protect new shoots using an appropriately labeled fungicide. The product label must include the site (e.g. landscape, nursery, etc.) and make certain peonies are not listed as being sensitive to the product. This is an added protective measure and requires just one or two applications. I have heard a number of anecdotal accounts of peony leaf blotch being successfully managed without these fungicidal applications in the spring. However, these applications should be considered if there were heavy Botrytis infections this season.
During the Growing Season:
- Remove and destroy bloom buds, flowers, and stems showing signs of Botrytisinfections. “Dead-heading” spent flowers is also recommended.
- Selectively prune plants to improve air circulation which will enhance leaf and stem drying.
- Avoid overhead irrigation; use drip irrigation if available.
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