If you notice that your trees are starting to look kind of ratty and moth-eaten, they may actually be moth-eaten. There are all kinds of bugs out there that are going to look at your trees as a huge all-you-can-eat buffet, and they are hungry. You can work to get rid of the bugs and help restore your tree to its former splendiferousness. The first thing you have to do in order to make that happen is to figure out what kind of insect is munching on your tree.
Gypsy moths are an introduced, invasive species. They were brought to the US in order to try to create a silk industry, but that didn't work out so well. However, they did show that they are hardy, hungry, and capable of spreading quickly. The gypsy moth now covers the entire US. Because they are invasive, they don't have a natural predator, so there really isn't anything that can help to keep them in check. So, what are the signs and what can you do to handle them? Eggs are laid in masses, and they can look like strands of hair. The masses can show up on your trees or the side of your house. The caterpillars are generally segmented, and each segment has a pair of colored dots. The male moths can fly and look grayish brown, while the females are too large to fly and are white. If you notice that you have egg masses, soak them in water or in a flammable fluid and light them up. If you don't notice the problem until you have caterpillars all over the place, you are going to need to have an insecticide to kill them.
Asian Longhorn Beetles
The Asian longhorn beetle is another invasive species, meaning that while there may be some animals which have discovered they are yummy to eat, they don't have a natural predator. These beetles, when in their adult stage, are black or dark brown and will have white spots. They also have long antennae, which make it look like they have horns. The beetles will lay their eggs in any hole in your tree they can find, and then the young will hatch and bore further into your tree, messing up the vascular system of your tree. The best way to get rid of them is to get rid of any affected branches on the tree by cutting them away. You can also find an insecticide that is designed especially for trees.
If your trees are starting to look bad, you may want to call out a tree care company like Brown's Tree Service and have them come look at your tree so that they can help come up with a plan for it.