Those yellow traps can be effective if a large number are deployed over several acres. A couple years ago, I put 15 traps out over 5 acres and put a dent in the local beetle population. Milky spore can be effective at killing the beetles that come out of your ground, but does little to stop the beetles that emerge from your neighbor's property and fly onto yours. Chickens also have a good reputation of killing the beetles.
Switching over from biological control to chemical/physical control, Neem oil and Chrysanthemum based pesticides (PyGanic, etc) supposedly knocks down the beetle population while Kaolin clay (Surround WP) may make the leaves irritating enough so the beetles move on to other trees/plants. Four O'clocks allegedly attract the beetles and are slightly toxic to them. This year I am trying out a combination of PyGanic and Surround WP, but the preliminary results have not been particularly encouraging.
Those traps work well. You can modify the catchment part so that the beetles drop down a pipe, and into a chicken enclosure. The chickens learn the sound of a beetle falling inside the pipe and will be waiting when it comes out the end.
Something in concept like this:
none yet, the flowers are slow to grow but luckily the beetles seem to not be an issue yet either, also my millipede issue hasn't reared its head yet so maybe I will get out easy this summer! Been slacking in the garden so maybe the plants they would otherwise be devouring just aren't out yet?
I treated about 1/4 acre around my main orchard with milky spore, and inoculated a few strips of my neighbors' yards on all 3 sides of me. This is three years later, and I have seen about an 80% reduction. They are now an annoyance rather than a biblical plague.
It's not an overnight fix, but the milky spore really does help.
Once the milky spore population is established, it becomes much more self regulatory.
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