I prefer to maintain a healthy and natural ecosystem in my garden. I don’t like using pesticides and I prefer less harmful methods to protect my plants, such as encouraging predatory insects and using traps. So for me, a non-native parasite, like invasive beetles, is a real problem. The Japanese beetle has invaded the gardens of southeastern Michigan and has damaged grass and other plants. My battle against them has been prolonged and frustrating.
Damage to Japanese beetles
These small beetles are actually quite attractive with a bright green metal exoskeleton. But if they’re in your backyard or garden, it quickly becomes obvious that they shouldn’t be welcomed. Michigan cockroaches have been a big problem for golf courses because their larvae feed on grass roots in the spring.
During my worst infestation, at the end of summer I found myself with dry and damaged patches of grass. Damage to the roots makes the grass particularly susceptible to drought. In a particularly bad season, the larvae attracted their predators, namely the crows, who waved the lawn in search of delicacies.
Adult cockroaches also nib all types of plants, from the leaves of fruit trees and shrubs to almost everything in the plant area. One year they did serious damage to my favorite Sharon squad, sketonizing the plant.
How I kept down the Japanese beetle populations in my backyard
To manage Japanese beetles, pesticides were not really an option. I don’t want to harm native species. So I used a combination of other strategies to keep them under control. First, I tried the traps, which are easy to find in nurseries, but they didn’t seem to help. A little online research told me that I was actually attracting cockroaches from other areas, potentially making my problem worse.
I also tried to increase populations of beetle predators, including tachinid fly, wasps and roundworms. I planted flowers on which flies and wasps feed, including lawns and Queen Anne’s lace. I used a beneficial nematode application designed to kill budding larvae.
I also spent many mornings collecting hand-drawn cockroaches from some of my beloved plants. It’s oddly satisfying to pick them up and drop them in soapy water, but this obviously takes time.
Improving the native ecosystem by planting native flowers and promoting predators has helped over the years. It wasn’t a quick fix, but it improved the situation. I must admit that when the cockroaches went to my beloved Sharon rose, I resorted to pesticides. I am not proud of it, but the problem was enormous.
I still have cockroaches around, but the problem is much less than before.