Canada thistle in southwest Ohio is starting to show symptoms of two “problems.” Bacterial infections are causing plants to look like they were dipped in bleach and the feeding damage by the Thistle Tortoise Beetle is beginning to produce see-through leaves.

Insects belonging to the Hemipteran family Reduviidae are collectively known as "Assassin Bugs." The family includes over 160 species in North America and all are meat eaters. The common name for the family clearly describes how these stealthy hunters make a living.

I’ve come to expect seeing some damage each spring from our native Four-Lined Plant Bug (Poecilocapsus lineatus, family Hemiptera). However, their wreckage appears to be particularly heavy this season in some parts of Ohio. The question “where did they come from” is common when hordes of hungry insect pests descend seemingly out of nowhere onto plants to cause extensive damage.

Japanese Tree Lilacs are in full bloom in northeast Ohio. They really grab your attention as you drive by with their showy white flowers that proliferate all over the head of the tree. They make you look twice and admire their beauty and form.

Sometimes you just have to stop what you are doing and appreciate plant life. Kenny Cochran of Secrest Arboretum fame always loved plants in combination, especially after he came back from a trip to Poland with an appreciation of clematis twining up trees, wild-like.  Today Paul Snyder of Secrest sent me a picture of blue spruce needles piercing leaves of Tim Brotzman’s great redbud:  Cercis canadensis Lavender Twist® ‘Covey’ and the two plants entwined. How cool is this? 

 

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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. Severe blistering can occur if chemicals (furanocoumarins (= furocoumarins)) in the plant juices come in contact with skin and the skin is then exposed to sunlight; specifically ultraviolet light. The effect is called phytophotodermatitis.

Before posting this bygl-alert, I had planned on reviewing the many cultivars of Chinese or Kousa dogwood that have entered the market in recent years, including Cornus kousa crosses with Cornus florida (our native flowering dogwood).  I will do this soon, but cannot wait. This is such a year for the kousa dogwood in my side yard that I must share pictures of it from this season right now.

 

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One of the things I ask my Sustainable Landscape Maintenance students at the end of the semester is to expound upon 10 Things They Learned in class. Most of these are the core of the course: including plant selection and knowledge, plant pest, plant maintenance, invasive species examples. Pete Grantham of Akron though, added:

 

  I learn from you so much about living in the moment, talked to me about your hitchhiking [the old days] and how you think it’s fun to run out of gas. These moments that others would consider worrisome are...

I came across a 'Princeton' American elm (Ulmus americana) planted in a county park in southwest Ohio sporting three pests: Woolly Elm Aphid, (Eriosoma americanum); Elm Cockscomb Gall Aphid (Colopha ulmicola); and European Elm Flea Weevil (EEFW) (Orchestes alni). EEFW is a non-native, but the woolly and cockscomb gall aphids are native insects that appear in pest records dating back to when American elms were "America's Street Tree."

Calico scale (Eulecanium cerasorum) eggs located beneath helmet-shaped females are hatching in southwest Ohio and the 1st instar nymphs (crawlers) are on the move. All nymphal stages are mobile, so all nymphs can be called "crawlers." The tiny, tannish-brown, oblong-shaped 1st instar crawlers are around 1/16" in length. They migrate to the undersides of leaves and position themselves along leaf veins where they insert their piercing-sucking mouthparts into phloem vessels to extract amino acids dissolved in the sugary plant sap.