This site is for people who like plants -- growers, enthusiasts, aesthetes, novices and professionals, those who appreciate wild things and those who appreciate the cultivated. I garden in Chelsea, and I've been visiting people's yards for 20+ years in the course of my work. My goal is to make this blog a community project, so if you share my interests, please consider becoming a participant and contributing content -- Guerin. Info: firstname.lastname@example.org
Monday, July 30, 2012
An oddball pest on pine, an oddball condition on oak
I once grew a nice specimen of swiss stone pine (Pinus cembra). It's a five-needle white pine of European origin, and it grows at a much more modest rate than our native Eastern white pine. Given that my specimen was likely one in only a very small number in my end of Washtenaw County, it was disheartening when it was located by an odd caterpillar that wrapped itself in the needles and made a total mess of it. The insect was the pine webworm. (Or maybe it was a false pine webworm. I couldn't exactly figure it out.) I attempted monitoring so that I could spray when the insect was small. I tried this for a couple years. I never saw a small insect. One day the plant looked fine, the next day the new growth was destroyed by this annoying pest. After three years, the tree went into the compost. This year I saw the same damage on a five-needle Japanese white pine. I've never seen it on our native Pinus strobus.
Here's another oddball phenomenon, this one on oak. I won't call it a pest because it doesn't do damage of any consequence. It's called the vein pocket gall, and it is caused by a tiny maggot-like insect that feeds underneath the swollen tissue. There's an impressive number of insect species that create different types of deformities on oak leaves. The swelling can look like a hedgehog (the oak-hedgehog gall) or an apple (the oak-apple gall) or a potato (the oak . . you get the idea). Inconsequential to plant health. Fun to collect!