"To every thing there is a season, and a time to every purpose under the heaven...
A time to kill, and a time to heal; a time to break down, and a time to build up..."
Ecclesiastes, Chapter 3
Martha and I grew up together in Maryland. We both fondly remember our brother tying threads around the necks of Japanese beetles in the 1950s, letting them fly around him in circles on their leashes. Now living in Michigan, Martha writes the lamentation below on her current (not so fond) experiences with Japanese Beetles. Looks like it's time to kill.
"I thought the JBs had disappeared after that, and chalked it up to DDT. Now, however, I realize that I was just out of the East Coast gardening loop for decades. Maybe they didn't go anywhere except off my radar screen -- and, at 1/4 mile per year, westward. A research proposal from 2005 noted, 'The Japanese beetle has now spread across most of eastern North America from Maine and Georgia west to Minnesota and Louisiana. Isolated infestations have now been found in many states west of the Mississippi River, including Colorado.' So, they're headed your way.
They reached Michigan in large numbers some ten years ago, and my roses in particular 3-4 years ago. I've tried traps, which caught thousands without appreciably thinning the numbers on my roses. I've tried Milky Spore on my lawn for the past two years, to no avail. (That could be for two reasons: I learned Thursday that the commercial products may not contain the actual effective milky spore, according to DNA testing; and my non-irrigated turf is likely not the home for their grubs anyway. My next-door neighbor, whose retirement has become full-time lawn care, has likely created the perfect conditions for them to thrive.) I've flicked them onto the patio or driveway and stomped them (satisfying but not effective on a grand scale). I've squirted them with Rose-RX and Safer Soap solution. They are still winning. My only success has come from planting double knockout roses that are resistant (and not all are!)
Now I am into biological warfare. One corner of Connecticut, scientists discovered many years ago, had a protozoan pathogen (Ovavesicula popilliae) keeping the beetles under control. It both kills close to 60% of the grubs (once established) and causes infected females to produce only half as many eggs. David Smitley of Michigan State University Extension (your tax dollars at work!) has been introducing them to public golf courses here and studying them since at least 1999. (An early layman's report notes that pathogens worked but parasites did not. Smitley has also done a lot of research on natural controls for the emerald ash borer -- too late for Michigan's ash trees, but maybe in time to save the baseball bat as we know it.) He held a Biocontrol Field Day about 15 miles from my home last week, to hand out dead and live beetles collected from his 'infected' sites. The dead ones are planted in the ground, so that grubs can be infected. Since my dry yard is not a great site for that (and my neighbor might shoot me if he saw me digging holes in his fairway), I got a Ziplock of a dozen or so live ones to release in my yard.
I am not the only one who came early so as not to miss out. Half of the 300 bags had been distributed before the official start time, and huge numbers of cars were still arriving when I left. Obviously, SE Michigan is ready to engage the enemy. The Judas beetles have now been spread much farther than they could have flown in a year. Optimally, it will take five years for heavy infection with the protozoan to become established and ten years for significant reduction in plant feeding damage. Perhaps I should start watering my lawn, to encourage egg-laying and the survival of the infected grubs. I'll have to lay off trapping and spraying for a few years, but it wasn't working anyway. I guess I could continue to flick and stomp, if I bury the remains. ;-)
I am attaching a photo of the buggers ravaging my roses ten minutes ago [expletive deleted]."