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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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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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...

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...

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  ...

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...

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...

The felt-like erineum patches produced by the eriophyid mite, Acalitus fagerinea, on the upper leaf surfaces of American beech are now appearing in southwest Ohio.  Currently, the patches are light-yellow.  However, they progress through several color stages throughout the season from light green in the spring to brilliant yellow to yellowish-gold then rusty red to reddish-brown and finally dark brown.

Although the patches are located on the upper leaf surface, they cause a dimpling of the lower leaf surface beneath the patch. 

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Last week, we reported that leaf and stem symptoms of the fungal disease known as sycamore anthracnose were becoming evident on the namesake host in many areas of Ohio.  This week, we're adding ash, oak, and beech to the list of foliar anthracnose diseases appearing in the southwest part of the state.  It's important to keep in mind that the anthracnose diseases affecting sycamore, ash, oak, and beech are each produced by a different host-specific fungus.  The fungus that produces anthracnose on sycamore does not infect ash, oak, or beech and vice versa; the fungus responsible for ash...

Wild parsnip (Pastinaca sativa) plants are rising towards their full height and blooms are beginning to appear in southern Ohio.  Landscape managers and gardeners should exercise extreme caution around this non-native invasive plant; the plant's juices can cause phytophotodermatitis (a.k.a. Berloque dermatitis).   If plant juices contact skin and the skin is then exposed to sunlight (specifically ultraviolet light), severe blistering can occur, as well as skin discoloration that may last several months. 

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