Emerald Ash Borer and Your Woods

Over the past couple of weeks I have received numerous calls from landowners concerning the status of their woods and emerald ash borer. A number of these calls were from landowners who have been approached by individuals telling them they need to cut their timber because the emerald ash borer will kill it all (including maple, oak and cherry). First off, if you are approached by an individual using this line I would recommend caution on how you proceed. Emerald ash borer (EAB), from our knowledge and experience in other states, attacks and kills only species of ash (green, black, white and blue). EAB will not attack and kill other species!

Emerald ash borer is headed this way. We don’t know exactly when it will get here. We do know that about 2/3 of the state is under a quarantine that doesn’t allow the movement of ash logs, chips and lumber into non-quarantined counties unless the logs/lumber/chips meet certain requirements. Bradford County is not yet under the quarantine. We also know that ash that is attacked will die. It may take two or three years but a successful attack is fatal to the attacked ash tree.

Here are some suggestions that may help a landowner deal with the certainties of EAB.

1. Don’t move firewood of any species. Use local firewood

2. Be alert to the condition of your ash component (a good publication to identify EAB is “Symptoms and Signs of the Emerald Ash Borer”, Extension Bulletin EAB – 2938-PSU, by Mary Wilson, MSU Extension and Eric Rebek, MSU, Dept. of Entomology).

3. Contact Cooperative Extension, DCNR Bureau of Forestry or Pennsylvania Dept. of Agriculture if you think you have EAB in your woods.

4. Determine the amount of ash in your woods. If you have an ash component that is greater than 10 – 15% of merchantable ash you may need to consider a harvest. At the same time you may carry out a timber stand improvement cut in the other species (“selective” cutting and only cutting trees above a certain diameter does not qualify as timber stand improvement)!

5. Learn all you can about EAB and your options by visiting websites, attending conferences and meetings, and reading material from creditable sources.

6. Contact your Bureau of Forestry service forester or your own forester and obtain his/her advice about managing your woods.

7. Obtain a forest management/stewardship plan or update your current plan with the appropriate EAB contingencies.

Even though emerald ash borer will likely have a large impact on the woodlands in Pennsylvania, it is not the time to panic. It is the time to obtain professional assistance and make knowledgeable decisions that will help you deal with this insect.

Evidence of woodpecker activity is a good sign of EAB infestation.

Forest Tent Caterpillar in the Future?

From my observations and from information received from Pennsylvania Bureau of Forestry, Forest Pest Specialists, the population of Forest Tent Caterpillar (FTC) appears to be on the rise in parts of the northern tier of Pennsylvania. These caterpillars are native insects that periodically reach high populations. They can defoliate an entire tree in a very short period of time. They are particularly fond of maple and aspen. They will also feed on a wide variety of other hardwood species. The eggs hatch in the spring about the time of leaf expansion. They tend to hang together in colonies and congregate during rest periods. They do not spin the large tents as do their relatives, the Eastern Tent Caterpillar. Five to six weeks after hatching they spin whitish-colored cocoons in bark crevices or rolled leaves. They emerge as buff-colored moths in about ten days. They mate and then the female lays eggs. The egg masses are dark and generally encircle a twig. The eggs overwinter and hatch again in the spring.

A very important parasite of this caterpillar is a large, gray fly. The populations of this fly can be very large during forest tent caterpillar outbreaks. They do not bite or sting people but they can be very annoying since they do like to land on people and regurgitate on buildings and hung-out laundry. The good thing about these flies is that they are a major factor in the natural control of FTC.

At this point in the life cycle of forest tent caterpillar, the adult females are laying or have already laid their eggs. It probably wouldn’t hurt to check out your trees, if you had some forest tent caterpillar, and look for egg masses in a few weeks. This can give you an idea if you may be dealing with this insect next spring. For more information go the Bradford County Extension website, click on the natural resources link and then the forestry resources link. Scroll down to the photo of the forest tent caterpillar and click there.

Eastern Tent Caterpillars Expected

The pesky eastern tent caterpillars will soon be hatching (in some places they may have hatched already). These caterpillars are most fond of cherry and flowering crabs. They can defoliate an entire small tree. They build large, ugly tents in branch crotches were they will hang out during the evening hours. When they first hatch out they are very small, indistinct caterpillars. They will immediately begin feeding on the newly emerging leaves. They are most susceptible to chemical control methods when they are small. The larger they get, the fewer the control options. You should never burn out the tents. Burning can cause damage to the cambium layer in the are burned. This can actually be more damaging to the tree than the caterpillars feeding on the leaves. The photo here you can see "mature" caterpillars in a large tent. For more information on eastern tent caterpillar go to Bradford County Extension Natural Resources Website, Click on the Forestry Resources link and and then scroll to the photo of eastern tents. Click on the photo and you will be taken to a helpful publication. You can also listen to a podcast about eastern tent caterpillars. At the natural resources website, click on the podcast, Northeast Pennsylvania Forests. Then click on the Eastern Tent Caterpillars title. For more specific control information call the Penn State Extension office nearest you.