Yard and Garden – 02-01-2014- Ted Griess / Extension Horticulture Assistant
I’m convinced readers will find today’s subject quite boring. For example, consider Neoclytus caprea, Agrillus abductus, Megacyllene robiniae, and Plectrodera scalator. All four are exceptionally boring.
The bitter-cold weather outside can be frightful. Enjoying the warmth of a roaring fireplace or basking in the radiant heat of a wood burning stove is usually delightful. Yet, for some, lounging by the fire can still be frightful.
Every year, about this time I receive calls from people who are startled by strange looking insects lurking about their homes. Such inquiries are not about ants, fruit flies or other common household insects. Generally I hear, “What are these fearsome looking bugs in my house? I’ve never seen them before. From where did they come? Can they cause harm? How do I get rid of them?”
Before answering their questions, I generally ask that they describe the worrisome guests. From the descriptions, I frequently resolve the dilemma. Wood-boring insects have invaded their homes.
Wood-borers such as Plectrodera Plectrodera scalator scalator, commonly called the Cottonwood Borer cottonwood borer, can certainly be unnerving. This six-legged, black and white beetle is huge — nearly two inches in length with antennae the same length. It is clearly understandable how such a beast can create fear in the mind of the beholder. Although intimidating, the good news is this beetle is harmless ―to the home that is.
Most trees are plagued with an array of insect pests. Wood-borers are one of those pests. Most tree species have a specific borer pest. For example, Neoclytus caprea is the banded ash borer. Agrillus abductus is the bronze birch borer. Megacyllene robiniae is the locust borer, and as mentioned earlier, Plectrodera scalator is the cottonwood borer. The life cycle of most all boring insects is similar, no matter the species.
During the growing season, the adult insects mate. The fertilized female lays her eggs on the bark of the host tree. The eggs hatch into tiny larvae which burrow beneath the bark of the tree and feed on the living tissue of the tree (cambium). After feeding for a given length of time, the now much larger larvae pupate. There, they undergo metamorphosis —hatching into adult insects. From there, the newly developed adults exit the tree to start the life cycle over again. While boring their way out of the tree, they leave tell-tale holes in the bark. In many cases, these insect pests can be harmful and even life-threatening to their host tree.
The simple fact is these insect pests came indoors with the firewood. The warmth of the home causes any embedded pupa in the firewood to hatch resulting in adult borers fluttering about the home. Although such insects can be harmful to trees—indoors, they are harmless. Even if the pest was a banded ash borer, and one has ash furniture or kitchen cupboards made of ash, the adult ash borer cannot harm them. It is only damaging to living ash trees. When found indoors, all one needs to do is grab the vacuum cleaner, and the problem is eliminated.
Borers are not the only insect pests that can hitch hike a ride indoors with firewood. Other insects transported indoors with the firewood might include termites, carpenter ants, horntail wasps, and bark beetles. Again, the good news is rarely, if ever, do these intruders cause harm to the home. It’s best to regard them as nothing more than annoying.
One simple way to avoid this situation is to properly store firewood outdoors — a topic for another day.
For now I’ll close this boring subject. Here’s hoping you will no longer be frightened but rather enlightened when strange, six-legged uninvited guests show up as you lounge by the fire.
Banded Ash Borer Bronze Birch Borer Locust Borer