Normally, I get dozens of calls on the GardenLine during the summer months asking; “What’s that eerie, silky web covering the trunk of my tree?” This summer, the calls have been scant, but they are picking up lately. I’m wondering whether it’s because we had a cooler and wetter-than-normal June. So, I thought in this week’s GardenLine email tip I would not only tell you all about it, but show you all about Bark Lice (Louse) and what it does(do) to a tree.
First, don’t panic, because this is a beneficial insect and not life-threatening to the tree in any way shape or form. And just as mysteriously as the web appeared on your tree it will disappear within a couple of weeks. That’s right, this phenomenon occurs suddenly and frequently overnight. You walk outside to get the morning paper and there it is, that eerie, silky web, coating the trunk of your tree. By golly, it has to be the work of some nefarious alien, doesn't it? I mean just yesterday, that same tree looked perfectly normal. And the Bark Lice’s (Louse) favorite targets are rough-barked hardwoods.
The reason these little critters are beneficial, is because they are doing you a favor. The lice scour the bark for fungi, spores, pollen, lichen and other debris which they eat. While performing this housekeeping chore they spin a web for their protection. And usually the web will disintegrate within a week, once they are done with that particular tree. Most people call in a panic, wondering what can be done. You don’t need to do anything. In fact, if you try to spray the web with an insecticide, it will bounce right off.
I searched high and low on the Internet to find you some pictures. While there are two places you can click on below, they aren’t the best examples of what the webbing look like.
Remember to leave these little guys alone if you do see such a web. They are a true definition of a “beneficial insect.”