Leaf Skeletons Evidence Beetle Damage
Every time we see Japanese Beetles on plants around here the leaves appear to have similar damage regardless of what plant serves as their perch.
I’m not sure what makes the fleshy green parts of a leaf taste “good” to a beetle, but that’s definitely their preference, if it comes down to that.
Maybe their mouth parts can’t handle the structure of the leaf ribs or maybe the stemmy parts don’t have the right flavor – can beetles taste their food and do they have a tongue? So many questions, so little time!
By skeletonizing we mean all the fleshy green parts of a leaf are eaten and the ribs remain. Only the shape of the leaf or outlined structure is left intact and the remainder of the leaves turn brown.
Damage by Japanese Beetles extends to blackberry, basil, cherry, purple cone flowers, roses, and many others.
How To Get Rid of Japanese Beetles
Get rid of Japanese beetles by knocking them off their perch into a pail of soapy water.
We take a drop of liquid dish soap in a milk jug about a quarter filled with water. The jug has been cut away as to have a large opening at the top and yet leave the handle and a large well for holding water.
The idea is to hold the pail of soapy water underneath a branch or limb to catch the falling insects as you tap the leaves or branches with the other hand.
A lot of insects and beetles would fly away when their perch is disturbed, but the Japanese beetles have a way of falling to the ground so it’s easy to capture them with a bucket held underneath.
If you only put in a couple of inches of water and one drop of dish soap, the milk jug container is pretty light to hold under leaves as you knock the pests into the water.
There’s no need to use a lot of soap – just one drop is plenty!
When the pail has collected enough beetles – you can use it for a few days – it can be dumped in a compost area or under a tree or shrub and let nature take care of the rest.
In Central PA we see the Japanese Beetles mainly in July and fewer numbers into August. In the middle of September we still see individual beetles among the anise hyssop or catnip tops at the edge of the garden and in random plants elsewhere.