Oak leaf blister is a disease is caused by the fungus, Taphrina caerulescens.  The fungus overwinters in infected buds and twigs.  Leaf infections occur during moist periods in the spring as leaves emerge.  Early symptoms appear as raised, blister-like, light-green to yellowish-green spots on the upper leaf surface matched with deep depressions on the lower leaf surface.  Eventually, the leaf "blisters" become very apparent as they turn dark brown to brownish-black.  The blisters may be evenly distributed across the leaf and are distinct from the angular, vein-based symptoms...

I planted a multi-stemmed Canada red chokecherry (Prunus virginiana 'Shubert') years ago in my landscaping so I could admire the deep, purplish-red foliage; a signature display of this selection.  Of course, that was before anyone knew it’s a magnet for the fungus, Apiosporina morbosa; the plant pathogen that causes black knot.  The disease is characterized by thick, corky, elongated gall-growths on twigs and branches that become coal-black late in the growing season; thus the common name for the disease.  Black knot is now the signature display of many Canada red...

First generation fall webworms (Hyphantria cunea) are appearing in central and southern Ohio.  Fall webworm moths typically have two generations per year in Ohio and despite their common name, first generation nests usually appear in late spring.  Fall webworm caterpillars only feed on the leaves that are enveloped by their silk nest.  As caterpillars grow in size, they expand their nest by casting silk over more leaves to accommodate their expanding appetites.

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In my back yard there are two sourgums, also known as blackgum or tupelo, with the lovely Latin binomial of Nyssa sylvatica. I grew them from young plants sold to me by Kenny Cochran at Secrest Arboretum, and now they have grown to the age that they are producing not only their glossy green leaves but also -  flowers.  

As the Missouri Botanical Garden website indicates, flowers are: “Primarily dioecious (separate male and female trees), but each tree often has some perfect flowers. Small, greenish-white flowers appear in spring on long stalks (female flowers in sparse...

In previous BYGLs this spring, we have noted the occurrence of heavy sycamore anthracnose statewide, and also of ash, beech, and oak anthracnose in southwest Ohio. This report from northeast Ohio is of one of the maple anthracnose fungal diseases. I was called out to a landscape in Doylestown Ohio where the homeowners were very concerned that “all of the leaves are fallin’” from a beloved maple tree that towers over their deck. We are all familiar with this sky-is-falling observation which in most cases turns out to be a bit overstated due to worry.

At most, probably less than 1%...

It is often said that a picture tells a thousand words. In this case, perhaps a few less, but it does tell multiple and layered stories. First, as shown by this image, one of the plant ID characteristics of elm (Ulmus) leaves is the uneven base to the leaf blade as shown here. This was the main point for the attendees at a recent Name That Tree program of OSU Extension at the OSU Mansfield campus. Secondly, of all the gall, the elm cockscomb gall insect (Colopha ulmicola) induced the DNA of this elm leaf to produce a proud new home for the insect’s progeny. Thirdly...

Ron Wilson (Natorp's) shared an e-mail message with me this morning from a listener of his radio show about a strange insect that kept "trying to cover itself with dirt."  An ID didn't come to my mind … I claim because of a lack of coffee rather than an age-related issue.  Ron chided me by repeating the part about the insect trying to cover itself with dirt.  My last functional neuron fired and I realized the message was about one of our favorite insects:  antions (Myrmeleon immaculatus).

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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.

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. 

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...