Kathy, a few years back we lived in a small town in which Dutch Elm trees had been planted all over the place, a number of years before.
Then, a plague of beetles came in that really liked the elm trees, which were now very large. The beetles killed any number of trees by eting the leaves completely from the trees, a number of seasons in a row. The trees then became un-sound, and it was necessary to take out lot of them.
We liked the one at our home. It presented a very nice visual improvement, and quite a bit of shade and natural air conditioning.
The larvae of the beetles dropped from the trees to the ground, then all marched to the trunk and began making their way up again, where they apparently went through their cycle after eating all the leaves.
We had to stop those beetles from reproducing!
I had no chemicals to use... But I had Duct Tape and plastic!
About 3ft up the trunk from the ground, I wrapped the clear plastic around the tree in a 1ft wide band, held in place with a few pieces of the tape.
Then, the upper edge of the plastic was tucked into the irregularities of the bark, to block the pathways. The bottom edge fluttered in the breeze, like a skirt.
Lastly, but most important, I made a few complete double passes round the tree with the duct tape, above and below where the plastic band was in place.
But I put these wraps of duct tape STICKY SIDE OUTWARDS !
The larvae got stuck on the duct tape! Those that made it past got to the plastic, and slipped off in any bit of breeze.
It was necessary for me to use the garden hose to wash away the huge pile of dead larvae at the base of the tree... more than a few times before they stopped, for that year!
It was a number of years back, and that tree is still standing, and healthy.
Many others were taken out.
Rather than using expensive storebought chems, I might suggest using dish detergent in water in a hudson sprayer... a pretty stout mix. It kills beetles on my squash plants on contact, in minutes. Actually less than minutes!
Downside?
Well, most bug-killing chems are toxic, and the chems in the dish detergent probably are too. But I *guess* they are ok, once rinsed???
We like dawn detergent best.
Good luck!
rc
Pls tell us how your fared in the battle!