By Staff
Any gardener recognizes the telltale damage of the Japanese beetle. The lacy, skeletonized leaves, eating only the tissue between the leaves' veins.
A hard-shelled beetle with metallic bronzy-brown wing covers (body), adults are half an inch long.
Feeding on a wide range of ornamental trees, the adult beetle's favorite snacks are roses, birch, plum, apricot, cherry apple, crabapple and peach. They will also feed on and defoliate a broad range of our garden plants.
And we all know their infamous young, a well-fed, C-shaped, three-fourths to 1 1/4-inch long white grub.
Even the word grub is repulsive. Moles, raccoons and birds seek them out with relish. Its main purpose in life is to eat the roots of our lawn grasses, causing spongy, discolored patches in them. And, if this isn't bad enough, killing off whole sections of our lawn at a time.
They are found in all states east of the Mississippi River, here in the Midwest, in the Northeast and as far west as Iowa, as far south as Alabama and in southeastern Canada, parts of Ontario and Quebec.
We all know and despise this critter all too well.
If we were to understand the Japanese beetle's life cycle, maybe we could use it to our best advantage – their destruction. It all starts in May to early July, as adult beetles emerge from the soil. Depending on the region, they begin to feed and mate. After all this fun, the females burrow into the soil, where they lay their eggs – not once, but several times.
Eggs hatch in eight to 14 days.
After they hatch they do a different type of damage. They feed on the roots of our lawns, weeds and ornamental plants (mostly our lawns).
About this time of year (October), the grubs burrow several inches deep into the soil for winter.
When the soil begins to warm in the spring, they crawl back to the surface to feed, fatten up grow and pupate.
In late summer and fall, when stresses like drought make the turf more susceptible, their damage to our lawns is very easy to make out and see.
Here are a few things we can do to fight these bugs.
Lawns with deep, healthy root systems seem to tolerate and bear up to grub damage best.
We must build up the grasses' roots organically, keep grass and plants healthy.
It is found that stressed plants are more susceptible to pests.
Moist soil attracts egg-laying females and increases the eggs' survival rate. We need to cut back on watering our lawns as soon as we see the first Japanese beetle.