Gypsy moths, with their brown triangular wings and habit of venturing towards the light, are interesting creatures. They're also problematic. If you have hardwood trees, you really want to avoid having gypsy moths around since they tend to lay their larvae on the tree's bark, where it feeds and causes damage to the tree. Older, weakened trees may begin to die back when infested with gypsy moths, and younger ones may become more prone to disease due to an infestation. 

There's no doubt that it's important to keep gypsy moths away from your hardwood trees. Here's how:

Keep your yard clean.

The moths are often first attracted to piles of leaves, rotting twigs and debris, and other such detritus. If you keep your yard cleaned up, there's a decreased chance of them showing up. Keep any compost in a compost roller, rather than out in the open. Burn your leaves at the end of the season, and trim any weeds along fences and structures.

Put a barrier around the tree trunk.

There are sticky bands that you wrap around the trunk of trees and that trap the gypsy moths. These are sold at most home goods stores, and you can apply them with the help of a friend. The moths lay their eggs in the leaves of the tree, and then when they develop into caterpillars, they drop to the ground before climbing back up the trunk. The sticky barrier keeps them from making the climb and then eating the tree's bark.

Use neem oil.

While traditional insecticides will keep gypsy moths away, they are not always the safest choice if you have kids and pets around. Since you would have to apply it to the trunk of the tree, so there's a distinct chance a child or pet could come into contact with it. Neem oil is a much safer alternative to pesticides. Some cultures even apply it to their skin, so you don't have to worry if someone touches it. Find a spray bottle applicator of the oil, and spray it onto the first five or six feet of the tree trunk. It will help repel the caterpillars as they try to climb back up into the tree.

If you notice a lot of gypsy moths around your tree and it seems to be ailing, contact an arborist. They may need to trim back certain branches or treat the tree to help revive it. Contact a local arborist for more information and assistance.