Holey Thistle!

Damage from the non-native thistle tortoise beetle (Cassida rubiginosa) is beginning to appear on its non-native, invasive host, Canada thistle (Cirsium arvense), in southwest Ohio.  The beetles are pale green or yellowish-green which allows them to blend with their host's leaves.  Like other tortoise beetles, the adults have a body shaped like a flattened pith helmet.  The head and legs of the adults are typically hidden under the flares of their helmet-like body.  The antennae can be hidden or extended out from underneath the front of the beetle.

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Joe Boggs

Who's Spittin' on My Dogwoods?

During today's weekly BYGL Inservice, Amanda Bennett (OSU Extension, Miami County) shared some striking images of the frothy, spittle-like masses produced by dogwood spittlebug (Clastoptera proteus) on its namesake host.  Spittlebug (family Cercopidae) nymphs are responsible for producing the frothy masses; adults of these insects are called "froghoppers" and have an entirely different life style. 

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Joe Boggs

Towering Poison Hemlock

Poison hemlock (Conium maculatum) is among the most deadly plants in North America.  This non-native invasive weed contains highly toxic piperidine alkaloid compounds, including coniine and gamma-coniceine, which cause respiratory failure and death when ingested by mammals.  The roots are more toxic than the leaves and stems; however, all parts of the plant including the seeds should be considered dangerous.  It is a common misconception that poison hemlock sap will cause skin rashes and blisters.  In fact, poison hemlock toxins must be ingested or enter through the eyes, cuts, or...

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Joe Boggs

Calico Scale Crawlers on the Move

Calico scale (Eulecanium cerasorum) 1st instar nymphs (crawlers) have been on the move in southwest Ohio and most have already settled on the undersides of leaves of infested host trees.  The tiny, tannish-brown, oblong-shaped crawlers are around 1/16" in length.  After hatching from eggs beneath females located on stems, the crawlers migrate to the undersides of leaves.  They position themselves along leaf veins where they insert their piercing-sucking mouthparts into phloem vessels to extract amino acids that are dissolved in the sugary plant sap.

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Joe Boggs

Hemlock Pine?

We sometimes forget “what it was like not to know”, when it comes to plant identification. Yet, it is essential when it comes to selecting and maintenance of plants. A simple misidentification of a pine vs. a spruce can result in improper pruning timing or improper diagnostics, prognostics, and recommended management for a disease: Diplodia tip blight of pine and Cytospora  canker of spruce are different diseases, obviously on different –plants. And spruces do not have “pine cones”.

 

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Jim Chatfield
Joe Boggs

Trees Take Flight

At a recent tree identification workshop I brought some samples of hedge maple (Acer campestre) and when the learners were keying these out I noted to them that stems had “wings”. Several attendees were more quizzical than usual at my ramblings and asked what I meant. “Wings” or raised or corky projections on stems of woody plants are perhaps most common with regard to winged euonymus (Euonymus alatus) from the Latin alatus which means “having wings or winglike extensions”.

There are many additional woody plant species that have “wings”, though, including...

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Jim Chatfield

Enjoy the Orchid-Like Catalpa Blooms!

I'm an unabashed lover of catalpa trees.  Yes, they are messy, but so are many of our "preferred" native and non-native landscape trees.  I loathe the subjective tree descriptor of "messy" because it removed so many wonderful trees from our landscape palette (e.g. sycamores).

Of course, catalpas do occasionally play host to hungry hordes of their very own caterpillar; catalpa hornworms are the larval form of the catalpa sphinx moth (Ceratomia catalpae).  The caterpillars only feed on catalpa trees.  However, as I discovered with a huge northern catalpa (Catalpa...

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Joe Boggs

Phomopsis Gall in Hickory

Phomopsis Gall on Hickory. 

An arboretum walk, a mature tree flowering and leafing out, a lovely spring day, a – gall. A bunch of galls, in fact, on this one tree. At first glance, the galls looked like horned-oak or gouty oak galls, round to oblong stem galls that occur on oak. The areas on the stems even looked sort of oak-ish at first, with masses of pollen-bearing male catkins evident. Not an oak, though, as the compound leaves attested. It was a hickory, and the galls, unlike the insect-induced horned oak and gouty oak galls, were caused by a fungus, the Phomopsis  ...

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Jim Chatfield
Joe Boggs

Horned Oak Gall Leaf Galls

When most people think of horned oak galls, they visualize the gnarled, woody stem galls that form on the twigs and small branches of pin oaks.  This is understandable since the gall-making wasp, Callirhytis cornigera (Family Cynipidae) that's responsible for directing the growth of the stem galls spends 33 months developing inside individual chambers within these very obvious galls.

The galls grow larger in size with each season.  In early spring, as the immature wasps near the completion of their development, the whitish-tan, cone-shaped “horns” that give this gall its...

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Joe Boggs

Oak Marginal Leaf Fold Gall

So-called marginal leaf fold galls are appearing on oaks in the "red oak group" in southwest Ohio.  The galls appear as rolled or folded leaf margins and are produced by a gall-making midge fly, Macrodiplosis erubescens (Family Cecidomyiidae).  As with the vast majority of oak galls, the leaf fold galls cause no appreciable harm to the overall health of affected oaks.  However, the gall has become notorious in recent years for its connection to a non-native predaceous mite (Pyemotes herfsi) that may feed on the gall-making midge fly larvae (maggots).  The mite...

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Joe Boggs