“Japanese Beetles are eating up my garden!”, is being exclaimed everywhere in the Central Virginia region this time of year. It seems this year the beetle population is heavier than we’ve had recently – maybe due to our mild winter.
Adult beetles emerge from the ground and begin feeding in June. They are most intense for 4-6 weeks after which they die off. A beetle’s life span is only 30-45 days (Did you smile?). Females leave your plants in the afternoon and bury 40-60 eggs over their life span in your soil most likely your expensive well -managed, lush, irrigated lawn. The grubs live 10 months in your soil burrowing as deep as 10 inches to survive winter temperatures. There are lawn services offering to eradicate grubs as a preventative. However, beetles will fly several miles to a new feeding ground if they need to. So, beware this does not prevent the problem entirely.
Here at Old City Cemetery we manage beetles on the ornamental pants they love by watching what they are feeding on. When we spot them we slowly and gently bend the branch of the shrub or plant over and then shake the beetles off into a scant filled bucket of soapy water. They move slowly in the morning and are easily captured. Often, because they tend to congregate on areas where they are feeding you can “capture” as many as 10 beetles per shake. Leaving several buckets of soapy water around the area of your yard where you notice them makes it easy to do this daily, several times if your schedule allows. When you are out deadheading and or pruning back your climbing roses that have crossed out of bounds into your paths it is easy to include this in your chores. The beetles can not fly out of your soapy water so this ritual is extremely gratifying to us gardeners. Oh, and by the way,
those yellow Japanese beetle traps we have all been desperate enough to buy at least once attract more beetles to your garden than are actually caught so I do not recommend those. This simple approach helps break the cycle and prevents them from laying grubs around your host plants.
To discourage these pests when choosing varieties to add to your garden plantings you may do a little research on their preferred eating habits. They feed on over 300 species of plant so it is not likely you can totally take away their menu but you don’t have to plant their favorites either. There are several references for this online. A table of preferred food sources can be found at www.entymology.ca.uky.edu .
Happy garden season. And remember, In August the beetles and the black spot (Diplocarpon Rosa) will both be better.
Article by Kaye Moomaw, Old City Cemetery’s Rosarian