Beware the Bugs – Common Tree Killers

Despite what one’s personal feelings may be about insects – they’re not all nuisances. Some bugs can actually save your trees. Others, however, can wreak havoc through entire forests and tree species.

So which bugs should tree lovers beware?

Gypsy Moth

gypsy moth

Did you know that the gypsy moth larvae has defoliated about a million forested acres each year since its introduction to the US in 1862? Gypsy moths have ravenous appetites, and while a tree is likely to survive one defoliation, the process drains the tree of valuable nutrients making it vulnerable to other infestations, rotting and disease. Multiple defoliations especially can cause significant damage to a tree and potentially kill it.

gypsy moth infestation

Emerald Ash Borer

Ash BorerThis insect has been a special nuisance throughout New Jersey this year and is worth keeping an eye on. The insect has already killed tens of millions of ashes in the Midwest. Now it’s here. In Philadelphia, when this insect made its way to Pennsylvania, the forest health manager at the PA Department of Conservation and Natural Resources was quoted as saying, “This is what’s going to happen: 99 percent of your ash trees are going to die,” If you see an Emerald Ash Borer, report it immediately. These insects spread rapidly and your local forestry departments can help to prevent them from overtaking the region.

Longhorn Beetles/Borers

Asian Longhorned BeetleThe adult ALB (Asian Longhorned Beetle) is a distinctive-looking insect with antennae longer than their bodies. This beetle was discovered on the East Coast in the late 90s and has since spread to at least 14 states. These beetles feed deep into the wood, disrupting the flow of water and nutrients in a tree until the tree essentially crumbles. If you see this beetle, report it here and call your local tree experts.

Elm Bark Beetle

elm beetleThe Elm Bark Beetle is the primary carrier of Dutch Elm Disease – a fungus that wiped out entire streets lined with Elms throughout the United States. Once beautiful parks and impressively shaded streets became desolate as the beetles carried the disease from branch to branch across streets, and the fungus spread root to root underground. No native elms are immune to Dutch Elm Disease.

Tent Caterpillars

tent caterpillarEastern Tent Caterpillars (above) are often confused with Gypsy Moth Larvae as they look very similar. Both cause defoliation, however and can be very harmful to trees. Eastern Tent Caterpillars are especially unloved by homeowners thanks to the ugly white tent the form at the forks of branches. Forest Tent Caterpillars (below) are much more harmful than ETC but, despite their name, do not build ugly tents in the trees. A lack of a tent does not mean the caterpillars in your tree are harmless. The Gypsy Moth and the Forest Tent Caterpillar are both capable of wiping out significant portions of tree populations through the defoliation of limbs. The favorite food of tent caterpillars is wild cherry, but oaks, maples and many other shade and forest trees are attacked.

tent caterpillar