Patterns of Life | Arts And Leisure

Summer in the Northwoods can feel like a painting – wide shades of green and blue create the background for highlights in all the colors of the rainbow.

However, winter can feel like a pen drawing, where shapes, textures, and patterns reign. I enjoy these changes of perspective as they can help me see new things.

Some time ago I was in a strip of weed vegetation between my friend’s driveway and a field. The colors of summer had almost disappeared from the thicket of goldenrod.

Where once sunny yellow flowers swirled over a sea of ​​green leaves, there was now a sepia-colored jumble of hazy seed heads, wrinkled leaves and crooked stems. In this winterized sketch, I scanned the lines and looked for a specific pattern.

Goldenrod galls are small, round lumps that appear near the top of growing stems in response to the chewing action of insect larvae.

Every year I collect a couple of gallon bags of these galls to use in our MuseumMobile lessons. With kitchen scissors in hand, I soon reached my goal.

Many of the galls were the typical, spherical houses of goldenrod gall fly larvae. But when I started sorting and slicing them, I found one that didn’t fit. It wasn’t much different – just bigger than it was wide, with some raised ridges.

I knew his real differences were hidden in it. A sharp knife around the equator of the gall soon revealed a hollow center with a shiny brown shell that rattled around.

The shell was the dried out puparium (like a pupa) of the goldenrod gall moth – Gnorimoschema gallaesolidaginis – whose larva produced this elliptical bile.

As I rolled the thin, mummy-like bowl in my fingers, it broke open. The cleavage did not result in a metamorphosing moth pupa that changed from larva to adult.

Instead, dozens of tiny, white, translucent larvae – each only about 2 mm long – poured out of the hollow cylinder. Any normal person would have been extrapolated. I was excited! The moth larvae are parasites on goldenrod and are themselves victims of many different parasites.

I wrote about it in 2017 when I found only a hollow, perforated shell that was cleaned by the larvae of a tiny wasp.

Based on some research and research, these translucent larvae likely belong to another type of tiny, parasitic wasp.

While wasps like these cannot sting us – their ovipositioning is only used to lay eggs – they play an enormous and largely hidden role in our ecosystems by keeping the populations of other insects in check.

I have currently hidden some of the larvae in a mason jar with a damp paper towel in the hopes that they will turn into adults and give us more clues as to their identity.

In the meantime I found another strange pattern in the lines of my winter forest.

On several snowshoe hikes recently, I’ve looked at the tip of bare branches that stand out against the sky and found a tree beneath them covered in clumps.

While these woody balls persist all summer, they are out of sight and out of your mind – hidden by that green wash.

Like the clumps on goldenrod stalks, I assumed it was probably galls. Plant galls are simply abnormal growths caused by viruses, fungi, bacteria, insects and mites, and even other plants. Which of these parasites could trigger such stubborn, woody galls?

The answer, according to a fact sheet from the Wisconsin DNR, is that these galls are caused by a fungus in the Phomopsis genus.

While little is known about how the fungus spreads, it appears to start on the smallest branches before moving on to larger branches.

Often only a single tree or a small cluster is affected. Some twigs or twigs may be girded and die, but the main tree will survive for many years. No treatment is available or even required, although you can cut off infected branches if you find them unsightly. I think it’s bizarre!

While I’ve mostly noticed phomopsis galls on northern red oak, they are also found on maple, hickory, and other species in Wisconsin.

The fungus causes galls on trees worldwide in Italy, Poland, Spain, Portugal, Switzerland, England, India, Russia, Tunisia and other countries. (This list comes from the titles of scientific journal articles written about the fungus, but could also serve as my post-pandemic travel destinations.)

The severe sketch of winter shows many patterns.

We see lines … and clumps where lines should be. We see the patterns of life interwoven.

The Cable Natural History Museum has linked you to the Northwoods for more than 50 years. The museum is closed, but our Mysteries of the Night exhibition is available online. Connect with us on Facebook, Instagram, YouTube and cablemuseum.org to keep track of our latest learning adventures.