Welcome back stalkers. This is the twenty-eighth issue of Stalking Mike Blair Outdoors. We hope you all are enjoying your summer and staying safe as you explore the world around you. What are some summer views you’ve been privileged to? Was it in your backyard? A local park? Did you travel somewhere? The beauty of nature can be seen everywhere. “Summer is moving on. Get out and enjoy it.” – Mike Blair-
Most (if not all) of you lovely stalkers are from the Midwest. If you are chances are you’ve probably seen this beetle. It’s one of the largest insects found in North America and is the largest of the Cerambyciae family found in the Great Plains. The size and look of this insect is startling to some people and fascinating to others. The reason you’ve most likely experienced this encounter at some point is that during both the larvae and adult stages the Cottonwood borer is completely dependent on the cottonwood (it will also use willows and poplars if it has to, but it prefers the cottonwood).
While this insect is a one part creepy it’s two parts fascinating. An interesting fact about them is that their bold coloration is not due to colors in the exoskeleton but instead to masses of small white hairs (only visible with magnification). The pattern the make is unique to each beetle, similar to a fingerprint, via Great Plains Nature Center.
The Cottonwood borer is active mainly in the summer and is found east of the Rocky Mountains. It’s a large, longhorn beetle that features black and white coloration with black antennas that are as long or longer than its body. They have very strong, large mandibles and jaws. This features allows the bug to chop and chew it’s way through bark and roots. They will bite, so be cautious if you handle one. You may hear them make a buzzing or hissing sound.
The female will chew small pits at the base of the tree; this is where she will lay her eggs. Larvae can take up to two years to mature, after that they pupate in a root below ground level for about three weeks. Once metamorphosis has completed, the adult cottonwood borer will chew its way out of the root and dig up to the surface.
Larvae can kill a cottonwood by girdling them. They also chew on the fragile root system until the tree can no longer gather nutrients or water from the soil. Larvae can also structurally weaken a young tree, which is dangerous in high winds, as the tree can fall over. Adult cottonwood borers feed on leaf stems and the bark of tender shoots, which can occasionally cause flagging. Most adult, large and healthy trees will be fine when a cottonwood borer is present. Young, small or unhealthy trees may not survive a cottonwood borer’s presence.