The proliferation of camera phones and digital cameras has resulted in many tree owners taking pictures of their tree or pest problems and submitting them electronically. I call these e-samples and I post the more interesting one on this website so readers can see what is going on in South Dakota.
Parson Spider (Herpyllus ecclesiasticus)
This is the time for the various insects and spiders to show up in homes and two interesting samples have come in during the past couple of weeks. The first is a spider, the Parson spider Herpyllus ecclesiasticus. These are fairly common spiders in homes and while a little scary looking, they do not pose much of a threat to people. A bite may result in a little swelling and itching but not likely more serious than that. The bigger concern is what are they eating? They are after other spiders and small insects so usually where you find Parson spiders there are other creatures lurking as well.The other sample is also more of a concern for what they represent rather than what they are.
A homeowner found floors covered with these small white “worms” but only in certain rooms. These are not powerpost beetles, another common insect found in wood homes, but blowfiy maggots. Usually when we find these on the floor they have dropped down from the ceiling and once the attic is entered a dead bat, mouse or rat (or raccoon in one instance) will be found and that is the source of the maggots. The only solution, once the dead creature is removed, is to close up any cracks in the attic that allowed the animal to enter. This sometimes is not an easy task as mice and bats can squeeze through some very small openings.
Elm Tree Issues
I also get a few tree pictures and questions at this time of year. One of the most common is why is there a long while streak on my elm tree? This streak sometimes still is oozing a liquid on warmer days.
This is a common problem with elms and cottonwoods and is called wetwood or slime flux. It is a bacterial disease that can result in wilting leaves and dying branches but usually the oozing of a foul smelling, alcoholic (but don’t drink it!) liquid is the only visible indicator of the disease. The bacteria lives in the sapwood and the fermentation activity results in the development of an alkaline liquid under pressure that is forced out of the tree through cracks and old pruning wounds. The liquid is so alkaline that it will bleach the bark white as it runs down the tree! Once it was a common practice to place a drain tube in the tree to relieve the pressure but now it has been found that wetwood reduces decay so it may even be a benefit to the tree