Defend your trees from the dreaded borer

This story is brought to you by LawnTech, a leading specialist for tree care, lawn care and landscaping in eastern Idaho.

One of the most common threats to your beautiful lilac and ash trees is the lilac borer.

Lilac borers (or lilac-ash borers) look similar to paper wasps, as they have yellow and black stripes across their bodies. The similarity ends there, however, as the borer is is technically a moth.

Lilac borers will burrow their way in from the bottom of the tree, and as they clean out these holes, they’ll leave sawdust-like shavings around the base.

Another sign that they’ve made your trees home is sap flowing from these small holes in the tree where larvae have burrowed in. When fully matured, they will emerge from the top and begin causing serious damage to the tree limbs. As branches begin to die, leaves will often wilt and turn reddish-brown. If left untreated for too long, they can even cause the tree to die.

The lilac borer can emerge as early as April, about one week after the tree has gone into full bloom, and will stay active well into June. These pests feed on the nectar of the tree and will lay their eggs right into its bark, giving them ample space to multiply. And though they lay their eggs in privet, lilac and ash trees, they won’t hesitate to attack any tree close by.

Their food source is also quite plentiful, since the larvae feed on the inside of the tree on the phloem (the living part of the tree).

The best way to protect your tree from the lilac borer isn’t to attack the borers themselves, though: it is ensuring that the tree stays healthy. This means preventing damage to the bark and making sure that you are not over- or underwatering your tree.

Weaker trees have a disadvantage when it comes to fighting off the lilac-ash borer. Studies have shown that stress or injury to trees will weaken them and leave them at greater risk to become infested with the lilac borer.

Aside from keeping the tree healthy, though, it is very important that a tree that is infested with the lilac-ash borer be treated as quickly and as thoroughly as possible. You can prune infected branches, and also carefully clean out the burrows with a knife or wire. (Careful not to damage the trees.)

You may also choose to seek professional help, as there are preventive, carefully timed treatment options available for trees that have previously become infested.