Here’s a version of a question I have been getting the last few weeks:
“While looking over my crepe myrtle (could be oak, maple, etc) the other day, I noticed a large group of black bugs on the bark of my tree and a fine tight webbing. None of my leaves appeared to be eaten. When I tried to scare them away with a branch, they scattered and then regrouped back on the tree. This group of black bugs has me worried. This is one of my favorite trees and I do not want anything bad to happen to it. Do you have any ideas as to what these bugs are and why they are on my tree?”
Not to worry! It sounds like you have tree cattle or barklice (louse). These are good guys. The tree cattle clean the tree by eating dead organic matter and lichens (algae and moss combination) out of the bark crevices of the tree. Even though crepe myrtles have smooth bark, there are plenty of places for the tree cattle to find food. They are the housecleaners of the trees! Maples are another favorite tree of the tree cattle.
These are the same bugs that produce that stocking like webbing that looks like something out of a horror movie. The webbing is tight against the bark of the tree just like a stocking. It is found on limbs as well as trunks of trees. The tree cattle use this webbing as protection from predators and weather.
Tree cattle do not harm a tree. They do not eat leaves, just dead organic matter. If they are really bugging you, you could spray them with a blast of water. I would let them clean the bark of the tree, so you do not have excessive organic debris buildup.
If you have a lot of lichens, you may want to check the general health of the tree. Lichens produce their own food like plants. So if you have a healthy thick canopy of foliage from the tree, lichens will not grow because they cannot get the sunlight they need to survive. A soil test and the appropriate fertilizer should help with this situation unless the tree has other cultural issues (compacted soils, wet soils, dry soil, planted incorrectly or in the wrong place …).
Last week, I laid to rest many fall army worms. They attacked my yard as well as my mother’s yard and my counter attack proved to be too much for them for now. They are known to launch a counter attack, so in a week or so I will launch a preemptive strike (if all goes as planned). I do not want to go out of town and return to a chowed on lawn.
The daylight hours are getting shorter. Time to get your preemergent product of choice out for winter annual weeds. Remember to treat your beds as well as your lawn.
Always read, understand and follow product label. The product label is a Federal Law.
Bill Lamson-Scribner can be reached during the week at Possum’s Landscape and Pest Control Supply. Possum’s has three locations 481 Long Point Rd in Mt. Pleasant (971-9601), 3325 Business Circle in North Charleston (760-2600), or 606 Dupont Rd, in Charleston (766-1511). Bring your questions to a Possum’s location, or visit us at http://www.possumsupply.com. You can also call in your questions to “ The Garden Clinic”, Saturdays from noon to 1:00, on 1250 WTMA (The Big Talker). The Horticulture Hotline is available 24 / 7 at possumsupply.com.