This species is really doing damage in my garden this year as it did last. The beetles are like small "june beetles' and feed at night on plant leaves. Go out tonight with a flashlight and examine any plants on which you've had lots of bugholes with no obvious bugs in the daytime.
They especially like my Centaurea montanta, most types of Chrysanthemums, peaches, and a few are found on many other garden plants. A few were there last night finishing off my sad nearly skeletonized Geranium pratense ( a hardy geranium) They were active on a my ailing Peach and hardly on my healthy looking Peach so they may prefer, or be more able to feed on, sick plants.
Handpicking is an option but I'm getting discouraged after 150 bugs in two nights.
Imidacloprid (Merit) insecticide is toxic to bees, according to recent studies. You may want to think about that before dosing actively flowering plants with this chemical.
The grub stage feeds on a variety of roots but not turf.
Last I read about milky spore it was very specific to Japanese beetles- But with these being similar, we could hope it gets them too and they simply don't have research to support that That question I have not really looked for . I have not used Milky spore here.
Here it is: http://www.gardensalive.com/article.asp?ai=768: "Misconception #1: “Milky spore (disease) ONLY works on JAPANESE beetle grubs. Dr. Klein explains that although it does work best against Japanese beetle babies, some strains have been shown to infect other white grubs—which is good, because other beetle grubs are learning how much fun it is to live in turf."
Picked fifty more beetles tonight; I am getting tired of this gig! I can hear the beetles flying around while I pick. I will confess I have used an insecticide drench on some of those non flowering plants that this beetle seems to like best.
So, sally how about an article from you on "The Night Garden"? or how to balance a flashlite and a cup of soapy water and still 'get' your target creatures...for us inveterate hand pickers!
This might create a noise problem at nite after 11 pm, but I use a small wet/dry vac with a long extension cord and a small crevice tool end to vacuum up unwanteds like stink bugs, JBs and gypsy moth caterpillers which die in the inch or two of soapy water in the tank. Like sucking up bb s you can hear them going to meet their fate and I am playing my part in balancing the over population of invasive insects with few natural enemies while not over burdening my environs with broad spectrum chemicals and their side effects.
Oh, my vac is strong enough to get the bugs but leave the plant (except for say, roses that would have broken up with a good wind or rain anyhow)
Last summer while eliminating stink bugs looking to overwinter by landing on and climbing the west facing side of my house, I rigged up a longer hose and attached it to a long bamboo pole and found I could reach up almost 25 feet to get those that had almost reached the roof peak.
One word of caution, try not to let the water/bug slurry in the vac splash on you especially with stink bugs on board in your enthusiasm to reach for just one more!
I have also used this to vacuum up those inevitable ant colonies that love my stacked pots
I'm going to post this on the other bug thread we have going here. too.