OSU Extension Greene County

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.

 

More Information

OSU Factsheet, Multicolored Asian Lady Beetle, ENT-44

https://ohioline.osu.edu/factsheet/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!

 

More Information

Great Lakes Apple Crunch Day

https://www.cias.wisc.edu/applecrunch/

 

 

 

 

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!

 

More Information

Link to Registration

https://woodlandstewards.osu.edu/events/why-trees-matter-forum

 

 

 

 

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!

 

More Information

Cigarette Beetle

http://entnemdept.ufl.edu/creatures/urban/stored/cigarette_beetle.htm

 

 

 

 

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.

 

Management

 

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!):

1. Cut, remove and destroy all of the top growth down to the soil line.
2. Rake, remove and destroy all mulch and plant debris that was beneath the infected plants.
3. 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.

 

Spring:

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:

1. Remove and destroy bloom buds, flowers, and stems showing signs of Botrytisinfections.  “Dead-heading” spent flowers is also recommended.
2. Selectively prune plants to improve air circulation which will enhance leaf and stem drying.
3. Avoid overhead irrigation; use drip irrigation if available.

 

 

 

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BYGL Weekly News for October 8, 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.

 

A Most Unusual Grub

Authors Joe Boggs

Published on October 6, 2018

 

 

I came across a green June beetle (Cotinis nitida, family Scarabaeidae) larva (grub) last Thursday slowly slinking across a driveway.  This is one of the largest and strangest white grubs you’ll ever see in Ohio.  First, the mature grubs are huge measuring well over 1″ in length.  They look like white grubs on steroids.

 

Second, the grubs practice a highly unusual mode of movement:  they crawl along on their backs in an undulating motion!  You can see this bizarre upside-down grub-crawl in a video I posted by clicking on “Grub Crawl” under “More Information” below.

 

The grubs rolling motion cause them to superficially resemble caterpillars.  In fact, when I first saw this grub creeping along, I thought it was a caterpillar.  Since green June beetles crawl without the aid of their legs, you’ll notice their legs are smaller than those of other white grubs, particularly in relation to the size of their bodies.

 

The other unusual thing about these grubs is that unlike other white grubs affecting turfgrass, green June beetle grubs create vertical burrows 10-12″ into the soil, and they normally remain closely associated with these burrows.  They primarily feed on decaying organic matter such as thatch and much of their damage to turfgrass is associated with their burrowing and tunneling behavior.  However, they have been known to feed on turfgrass producing damage in irregular patches.

 

The grubs venture out of their burrows in late-evening or during the night to feed or to go on an upside-down crawl-about in search of more food.  They may also be driven out by heavy rains to appear in large numbers meandering across driveways and sidewalks or dropping into swimming pools.  Although they can damage turfgrass, they’re primarily considered a nuisance pest.

 

The same is true of the large, metallic green adult beetles.  Although they may occasionally feed on tree leaves as skeletonizers, or they may be found on ripening fruit, the beetles are most notorious for emerging en masse to terrorize backyard gardeners, golfers, sunbathers, small pets, etc., as they cruise about 2 – 3 ft. above the ground.  Their large size coupled with an audible “buzzing” sound and low-level flight plan may induce mild panic in individuals unfamiliar with this insect.  Like their grubs, the beetles have great entertainment value.

 

There appears to be a strong association between high organic and high populations of this beetle.  So, control efforts should focus on reducing organic matter, particularly thatch, beneath infested lawns.  For example, thatch reduction using core aeration to hasten decay by infusing oxygen into the organic matter may eventually make infested lawns less attractive as grub development sites by these buzz-bombing beetles.

 

The grubs are also food for the larvae of the blue-winged wasp (Scolia dubia).  This wasp is a common visitor to late-season blooms such as those produced by goldenrod (Solidago spp.).  Providing a good late-season nectar source, such as planting late-bloomers in landscapes, can help draw in this parasitoid wasp.

 

On a final note, I posted a BYGL Alert about this wasp just a few weeks ago (see Blue-Winged Wasps Cruising Lawns, September 17, 2018) and incorrectly stated that it is “a parasitoid of white grubs with a particular affinity for green June beetle (Continus nitida) and Japanese beetle (Popillia japonica) grubs.”  This is only half-right.  As turfgrass entomologist and (thankfully!) BYGL fact-checker, Dan Potter (Entomology, University of Kentucky) pointed out, there is no scientific evidence this wasp attacks Japanese beetle grubs.  However, it’s well established that the wasp is the nemesis of green June beetle grubs.

 

More Information

Grub Crawl

https://youtu.be/EF8UeznxE5M

 

 

 

Bullet Galls and Their Guards

Authors Joe Boggs

Published on October 6, 2018

 

 

Oak bullet galls have reached their maximum size for the season and will soon release their developing female wasps.  The galls arise from twigs and are produced under the direction of several species of cynipid wasps (family Cynipidae) belonging to the genus Disholcaspis.  So, you may find different types of bullet galls depending on the exact gall-making wasp species that directed their creation.

 

Most bullet galls are more or less round-shaped and measure about 1/2″ in diameter.  Colors vary from light green to reddish-green, to light brown depending on the wasp species and the age of the gall.  Some bullet galls are covered in very fine, short hairs, while others are completely smooth.  They cause no appreciable harm to their oak hosts because they do not disrupt the vascular flow in the twigs.

 

Complex Life Cycle

 

The life cycle of bullet gall-wasps involves two different types of galls produced at different times of the year.  The current bullet galls will give rise to female wasps around the end of this month; no males are produced.  Wasp emergence is heralded by a small hole in the gall.  Once the wasps have emerged, the “spent” galls shrivel, darken in color, and some will detach from the oak stems over the winter.

 

The self-fertile females crawl to a dormant leaf bud where they lay a single egg per bud.  These eggs along with the resulting wasp larvae stimulate the tree to produce small, inconspicuous leaf galls in the spring.  Both male and female wasps develop inside these leaf galls and adults emerge in mid-to-late spring.

 

The mated females fly or crawl to newly elongated twigs where they insert their eggs through the phloem to be in contact with the cambium.  Or, depending on the gall-wasp species, they insert an egg in a new leaf bud.  This is important because the wasp requires the services of undifferentiated (meristematic) cells to grow their bullet galls.

 

As with all galls produced by wasps, midge flies, and other insects, the bullet wasp gall-maker uses various chemicals to turn plant genes on and off at just the right time to induce and direct gall formation.  Thus far, no researcher has ever duplicated this interaction without the aid of an insect gall-maker.

 

Paying for Protection

 

Many bullet galls include extrafloral nectaries (a plant organ) in their gall structure.  I find this to be incredible, but it’s not unique to bullet galls.  A number of other cynipid wasp galls also exude nectar including the oak bud gall produced by the wasp Neuroterus vesicula.

 

The nectar exuded from the galls attract a variety of stinging insects including bald-faced hornets (Dolichovespula maculata) and yellowjackets (Vespula spp.) as well as biting insects such as carpenter ants (Camponotus spp.).

 

Yellowjackets and bald-faced hornets are Jekyll and Hyde wasps.  During much of the season, they chow-down on soft-bodied insects such as caterpillars and sawfly larvae.  Their predatory lifestyle makes them beneficial insects.  However, in the fall, they switch from high-protein diets to high carbohydrate diets.  They can be a serious stinging-nuisance as they compete with our own high-carb consumption of soda, donuts, and certain adult beverages.

 

Bullet gall-makers take advantage of the wasp’s high-carb hankering with the nectar oozing from the extrafloral nectaries on the galls serving as “wasp candy.”  Of course, ants will also show-up to the sugar party.

 

Presumably, the close attention of stinging and biting insects prevents the immature gall-making wasp larvae located within the galls from receiving the unwanted attention of predators and parasitoids.  In other words, a little sugar bribe makes the gall-home safe for the gall-makers helpless offspring.

 

 

 

Small but Mighty Fly

Authors Joe Boggs

Published on October 5, 2018

 

 

I came across a beautiful little native fly this week while taking pictures of pollinators on common goldenrod (Solidago canadensis).  The fly, Trichopoda pennipes, doesn’t have a common name, but some web-based resources refer to it as the “feather-legged fly.”  This is not entirely correct.

 

It is just one type of feather-legged fly with the common name given to all members of the Trichopoda genus.  The name of the genus comes from the Greek tricho meaning “hair;” and poda meaning foot.  In fact, some refer to these flies as “hairy-legged flies.”  Even with the naked eye, you can clearly see the hair-like structures on the hind tibia that are responsible for the common and scientific names.

 

I came across an online resource that referred to Trichopoda pennipes as the orange-and-black feather-legged fly.  Although this common name hasn’t been approved by the Entomological Society of America, I like it because it’s so descriptive. So, I’ll refer to it in short-hand as the O&B fly.

 

Other fascinating features that are clearly visible on the O&B fly are their two wings which mean it’s truly a fly belonging to the order Diptera:  Di = two; ptera = wings.  Flies actually have four wings but the hind wings are modified into two knob-like structures called halteres which are used by flies for balance during flight.  It’s one reason flies are such good flyers and are called flies.  The saddlebag-shaped halteres on the O&B fly are relatively large compared to many dipterans and they are covered in orange scales making them easy to see.

 

The O&B fly belongs to the fly family Tachinidae (the parasitoid flies) and is found throughout much of North America.  Members of this family are well known for their prowess in tracking their hosts and for their larvae (maggots) ravaging their hosts from the inside out.

 

The O&B fly focuses its parasitoid scrutiny on the “true bugs” (order Hemiptera, suborder Heteroptera).  They can pay particular attention to some significant stink bugs (family Pentatomidae) including the southern green stink bug (Nezara viridula) notable for damaging cotton and other field crops and the brown marmorated stink bug (Halyomorpha halys) notable for damaging a number of different crops then invading homes to brag about it.  The fly will also parasitize various leaf-footed bugs (family Coreidae) such as the squash bug (Anasa tristis).

 

Research has shown that sex pheromones used by the southern green stink bug females to attract mates can be detected and used by the O&B fly to zero in on the bugs.  This devious host detection method is not unique to this fly; it’s been reported with other tachinid flies.

 

Once a bug host is located, the O&B fly females lay single or multiple eggs on the surface of their host.  The resulting fly maggots bore into their host; however, only one maggot survives to consume the entire contents of their bug host.  Again, this is not unique to this fly, or even to flies.  There are some parasitoid wasps that also subject their offspring to a survival of the fittest test.

 

Some parasitism rates by the O&B fly that are reported outside of scientific publications sound too good to be true, so they probably are.  However, various research papers do indicate this fly can have some significant impacts under certain conditions.

 

For example, there appears to be a connection between nectar sources, successful adult mating, and higher rates of parasitism.  Yet another example of the value of providing food for a pollinator adult (e.g. butterfly gardens) so their parasitoid or predator offspring can help reduce the number of nearby plant pests.  Where have you heard that before?

 

 

 

ArborEatYumm: OSU’s College of Food…

Authors Jim Chatfield

Published on October 4, 2018

 

 

…FOOD Agricultural and Environmental Sciences. Let it never be forgot, the centrality of FOOD. Even in the landscape. So, Come one, come all.  Next Tuesday, October 9, at OSU’s Secrest Arboretum, from 5:00 – 8:00 pm, there will be a free Arbor-Eat-Um program. Edible landscaping. Bring your favorite landscape plant products that are edible: blueberry buckle, black chokeberry jam.

 

Mark Hoenigman and his pawpaw trifle, Cathy Herms and her Autumn olive pate de fruits – controlling invasives one bite at a time. Lois Rose and her Medlar jam. Ramp soup. Honey. Maple syrup. Dolgo crabapple butter – Mike Lee where are you?

 

Nothing from your landscape?  Just bring your appetite. Miller Pavilion. You do not need to register. Be there.

 

 

 

What Lies Beneath

Authors Joe Boggs

Published on October 3, 2018

 

 

I enjoy making unexpected discoveries with one revelation leading to the next and then the next like pulling apart one of those Russian nesting dolls.  My chain of discoveries started with finding “fresh” puffball mushrooms during a walk in a local park.  I was thrilled because I had never taken pictures of the early stages of these peculiar looking mushrooms.

 

Puffballs are the common name for the fruiting structures of a group of fungi that were once lumped together in the descriptively named but now obsolete taxonomic class, Gasteromycetes (Greek:  gaster = stomach; mycetes = fungus).  Unlike the mushrooms that we may love on our pizzas with the spores produced and released from external gill-like structures beneath a cap, the spores in puffballs are produced internally inside a hollow cavity called a gasterothecium (= stomach-like).

 

The puffballs I came across with their white, spongy interiors will eventually undergo a dramatic change to become brown sacs full of powdery spores that puff when squeezed; thus puffballs.  I hope to return to capture the next phase in their development unless someone steps on them to release clouds of spores.  Puffballs have great entertainment value.

 

I pulled up one of the puffballs and discovered the bottom was riddled with pits and holes created by pillbugs as they dined on the fungal delicacy.  I was thrilled because I had no pictures of these odd looking terrestrial crustaceans (phylum Arthropoda, subphylum Crustacea).  It was like lifting off the top of a Russian nesting doll to discover another doll hiding beneath.

 

Pillbugs are so-named because they roll themselves into a pill-like ball when disturbed.  This odd behavior gives rise to other common names such as armadillo bugs based on their roll-up behavior coupled with their obvious body plates.

 

You see this common name reflected by name of the pillbug family, Armadillidiidae.  It also appears in the name of the genus of the two most common pillbug species found in Ohio, Armadillidium vulgare (common pillbug) and A. nasatum.  Both are European natives that were introduced to North America so long ago it’s now common to think of them as native species.

 

Pillbugs live in dark, moist environments and are generally considered to be detritivores feeding on decaying plant debris.  However, on rare occasions, they may feed on living plant material and have been known to cause damage to vegetables including root crops like radishes and carrots as well as lettuce leaves and ripe tomatoes.  They may also become serious greenhouse pests by consuming seedling roots and young stems in contact with the soilless media.  However, pillbugs are mostly just nuisance pests because of their propensity to show up in large numbers where they’re least appreciated such as in cool, wet garages and basements.

 

Sowbugs (family Oniscidae) are not the same as pillbugs although they both may be found living in the same locations.  Sowbugs have two, small, pointed tail-like appendages that stick out of their back ends.  Pillbugs do not.  However, the big difference is that sowbugs cannot roll their bodies into round balls.  They may huff and puff and curl a bit, but they just can’t pull off the rolly-pollie body tuck.

 

Pillbug management around homes should focus on prevention through closing entry points and environment modifications to promote drying.  Door sweeps and door jambs should be inspected and action taken to close gaps that have become too wide.  Pillbugs benefit from high moisture, so running dehumidifiers will help keep basements and garages dry.  Mulch should be raked away from foundations to produce a “dry barrier.”  Also, decaying vegetation should be removed.

 

Of course, there are things that eat pillbugs which brings me to my third Russian doll discovery.  While taking pictures of the pillbugs crawling in and out of the cavities in the puffball, I came across a voracious predacious soldier beetle larva (Chauliognathus spp., family Cantharidae).  The soldier beetle larva was thrusting itself into the cavities to enjoy a pillbug meat treat.

 

Adult soldier beetles are also called “leatherwings” for their soft, flexible front wings.  The adults feed on nectar and pollen and are considered important plant pollinators.  In fact, goldenrod soldier beetles (C.  pennsylvanicus) are currently swarming over the flowers of its namesake native host plant.  Another common Ohio species, the margined leatherwing (C. marginatus), made its appearance this past spring and early summer on other flowering plants.

 

Soldier beetles and their predacious larvae are a good example of the value of providing food for a pollinator adult (e.g. butterfly gardens) so their predaceous larvae can help reduce pestiferous arthropods.  Research has shown the same is true for pollinators with parasitoid larvae.  It’s like opening a Russian nesting doll to discover unexpected treasure hidden beneath.

 

 

 

Diagnostics of Beech Leaf Disease: The Ultimate Beech Read

Authors Jim Chatfield  Joe Boggs

Published on October 2, 2018

 

 

Our knowledge of Beech Leaf Disease (BLD), an emergent problem on American beech (Fagus grandifolia) in northeast Ohio and nearby areas is still in the early stages. For example, we do not know what causes BLD.  The most promising development in learning causation is that we now have scientists with some grant funding on the case. Carrie Ewing in Enrico Bonello’s lab at Ohio State University is doing her PhD work on BLD.

 

We also have excellent monitoring and mapping of the disease, including Lake Metro Parks and BLD discoverer John Pojacnik and Cleveland Metro Parks, as well as the Ohio Department of Natural Resources Division of Forestry and Holden Arboretum.  But we do not know what causes BLD, if it is a pathogen whether it has a vector, the long-term threat to forest and landscape beeches, and on and on.

 

We do have some diagnostic aids: what BLD looks like as well as other problems that are often misdiagnosed as BLD. So here is the first in a series of BYGL BLD Diagnostic comparisons. We have discussed BLD in a number of previous BYGL-alerts (https://bygl.osu.edu/node/885), but here is a one on one comparison of look-alikes and diagnostic beech mis-reads.

 

BLD vs. A Leaf Curling Aphid.

 

I find this to be the most common BLD mis-read. I wish I could tell you the species of the aphid in this example: I cannot, but it is common in most beech woodlands on a few or many trees. At least I think it is the same aphid; it may very well be that there are a number of aphids that cause this leaf curling on beech. As you can see from the picture, the symptom on beech is the curling of leaf margins, with the sign of the aphid typically being cast skins of the aphids within the curled leaf. Presence of these aphids is not correlated with BLD.

 

As you can also see, there is a leaf discoloration symptom associated with the leaf curling. This is the key to it being mistaken for Beech Leaf Disease. The yellowing near the infestation is mis-interpreted as the “banding” symptom on BLD. With BLD though, there is clear banding of deep green and lighter greens, not this yellow banding noted from the leaf curling aphid.

 

This leaf curling aphid causes truly minimal damage to the plant. BLD, on the other hand is a serious problem, causing considerable progressive thinning of the canopy and in some cases tree death. So, check it out when you see beeches in the woods BTW, our landscape European (F. sylvatica) and Asian beeches (F. orientalis and others) have been diagnosed with BLD in nurseries.

 

Next time, let us remind ourselves of two other aphids that occur on beech: boogie-woogie aphids on American beech and woolly beech aphids on European beech. Also, neither of which is BLD.