July 21, 2016
There have been a lot of garden problems that have cropped up this past week so I figured that this weeks column will be “ a little of this and a little of that”.
I think that the most common question has been about this year’s invasion of the gypsy moth caterpillar. If you remember back to early spring, we had many of our maple trees attacked by the winter moth caterpillar. This tiny caterpillar started feeding as soon as the leaves unfolded on the trees. They fed for about 6 weeks and they were gone. Un-be-knownst to may people, in early May, the gypsy moth caterpillars began to feed on oaks and maple trees. If people thought the winter moth caterpillars could do some damage, it soon became apparent that the gypsy moth caterpillars were present in large enough numbers to strip all the leaves off of some trees. The question people have is what can they do now to control these caterpillars. At this time of the year, there really isn’t much you can do. The caterpillars have stopped feeding and they are now emerging as adult moths. The moths mate and the females lay egg cases on the trees. Soon, the moths will all die and the egg cases will wait until May to hatch.
The interesting thing is that the gypsy moth caterpillars have been around our area for more than 100 years. In the late 1970’s into the late 1980’s we had a huge invasion of the caterpillars. They defoliated the trees and even began to eat needles off the pine trees. What finally put a stop to the huge population was a combination of a specific fungus and a specific virus that exists in the soil. For more than 30 years, this combination of the fungus and the virus has kept the population in check. It would appear that the reason the gypsy moth caterpillar population has rebounded is because the fungus and virus need moist soil in the spring in order to become active enough to kill off the caterpillars. Even though we had a lot of snow in the winter of 2014 – 2015, the soil dried quickly that spring. We had very little snow or rain this year so the soil in the spring was dry. This back-to-back years of dry spring conditions has lead to the gypsy moth caterpillars getting a foothold back into our trees. The hope is that this winter we get normal snowfall and that we get normal rainfall in the spring. If these conditions happen, the fungus and virus will grow to sufficient levels that it will knock back the gypsy moth caterpillars. Only time will tell.
One of the other problems that has happened and that has raised a lot of questions concerns the number of small branches that have fallen off the oak trees. The branches are small and they appear to have been chewed off the tree. It answer is that squirrels will commonly chew through branches to make a nest in the trees. Occasionally they will drop a branch. With a large increase in the squirrel population this year, we naturally have more branches being dropped.
Speaking of a large squirrel population, it has been a banner year for large populations of squirrels, chipmunks, rabbits and woodchucks. Due to a dry spring and summer, these large populations have been looking for food. Our flower and vegetable gardens have been a good source of food for all these creatures. However, when animal populations get too high, Mother Nature will release some type of disease that will kill off the vast majority of the population. It may not happen this year, but I wouldn’t be surprised if next year people are asking, “What has happened to all the squirrels, chipmunks, rabbits, woodchucks? “. If so, I will need to cut back on the amount of animal repellents that we stock in the store.
Well, that’s all for this week. I’ll talk to you again next week.