Signs of wood rot (and true love)

, - November 30, 2011

Editor’s note: This article is from the archives of the MSU Crop Advisory Team Alerts. Check the label of any pesticide referenced to ensure your use is included.

Back in the early 1950’s my parents built a simple, but homey ranch house outside of Stevensville in Berrien County. The site was a challenge with its location in the low point of the land and a soil type approaching what seemed to be 110 percent clay. Soil moisture availability was rarely a problem, except in the basement.

They landscaped the three acres they owned with free trees and shrubs obtained from relatives and friends, mainly Norway spruce and silver maple (Acer saccharinum L.). One silver maple grew at an impressive rate, as it was partially rooted in the septic field. As it turned out, it was also located in the whiffle ball field, right at the shortstop position. As my three brothers and I grew older (but never grew up), we played countless games of whiffle ball and the tree became officially known as “Shortstop” in the manner that great sequoias and redwoods are named.

In recent years, my brothers and I finally got too old to play without almost immediate joint pain, and Shortstop started showing signs of age as well. One of the first warnings was a slime flux, possibly the rudest-sounding of all tree disorders. Then a few large branches died back, and last fall, the fruiting bodies of several species of fungus appeared at various locations on the trunk. We made the tough decision that Shortstop had to come down before it fell down, as it was close enough to the house that some pretty major damage might be done if the wind came in the wrong direction.

The tree was cut down on March 20, and unfortunately I was unable to be there to take pictures of the process. I arrived a few days later to see that the arborist did a nice job of cutting most of it into firewood per my instructions, but some parts of the trunk were left in huge, impressive sections, some close to four feet in diameter (mind you, this tree was only about 56 years old).

Amongst the pieces of Shortstop were sections of a main branch that featured a rotted tree hole that formed where a large branch had once been pruned off in a manner that did not allow the wound to heal. I vaguely recall that I did the pruning, obviously before I had been taught proper pruning techniques. The internal cavity of the tree hole had been cut in half, so I had complete access to all the muck and mess of the rotted leaves that were left over from the nests of many generations of squirrels. I knew this had to be explored… there were so many entomological possibilities in such a habitat. Eureka, rat-tailed maggots!

Appreciation of a good rat-tailed maggot is a sure sign of either an entomologist or an all-around nature-lover. They are interesting creatures, specialized for living in poorly-oxygenated aquatic or semi-aquatic environments with long, extendable tails used to reach the surface to obtain air. Several species are known to inhabit tree holes. They are members of the Dipteran family Syrphidae, which includes species with quite varied habits, all the way from valuable aphid predators to pests of ornamental plants, like the narcissus bulb fly. The adults typically are mimics of bees or wasps, and are frequently found at flowers.

My mother happily helped me scrape out all the contents of the tree hole, and together we picked out over 200 plump rat-tailed maggots from a volume of muck that was no greater than a quart jar. Obviously, my mother loves me. One might think she’d be the only one who could, but….

I called my wife back at home right after the rich harvest of maggots, as she could not be there in person due to a very serious illness. Did I start with “How are you feeling?” or something like that? No, I proudly announced the capture of 200 rat-tailed maggots, and she was thrilled. That, my Landscape Alert friends, is a sure sign of true love.