Rachel and I try to keep our columns timely with what’s going on in our garden. Since none of us live in isolation, whatever’s happening with us is probably happening with you, too. Unfortunately, Japanese beetles are back.
This is the fifth year that they’ve plagued our garden, and each year is worse than the one before. During the beginning of the season we thought we had them under control. By mid-July we were completely overwhelmed. It wouldn’t be an exaggeration to say that we’ve killed thousands of these pests over the past two weeks. Looking at our garden though, you’d never know it. They’ve done extensive damage to our roses and food crops and tested our resolve to carry on gardening for the rest of the summer. We’re angry, but more determined than ever to overcome this insect invasion.
In 1912, Japanese beetles were unintentionally brought into the United States from Japan in a shipment of irises. They made their way west from New Jersey, and were first detected in Kansas in 1949. By 1992, the Kansas Department of Agriculture declared Japanese beetles to be firmly established in the state, and further attempts at eradication were ended. Because they have few natural enemies, they’ve become firmly established in most areas east of the Rocky Mountains. Their westward migration continues.
Japanese beetles are approximately the size of a dime. They have metallic green bodies with copper-colored wings and tufts of white hairs protruding from their sides. They begin their lives as C-shaped white grubs that overwinter underground. They feed on the roots of turf grasses which can slowly destroy wide sections of lawn. The adult beetles emerge from the soil in mid-June and begin the second phase of destruction. They are capable of flying up to several miles from where they emerge. According to the USDA, they infest more than 300 plant species. They feed on the leaves, flowers, fruits and vines. They’re capable of defoliating trees, shrubs and garden crops during their six-week life cycle. When they feed on leaves, they only eat the soft parts, not the veins. The tell-tale sign of Japanese beetle destruction is the skeletonized leaves left behind. Not only have they eaten our roses, they’ve also destroyed our green beans, strawberries and okra. Just yesterday, I noticed them on our brand new apple tree. The pungent aroma from our herb garden hasn’t stopped them from eating our basil either.
Not wanting to poison any pollinators, or ourselves, we haven’t used any chemical insecticides. We seemed to be doing well with neem oil, but the necessary frequent applications became too burdensome. The USDA suggests planting species that are resistant to Japanese beetles. For rose lovers, this really isn’t an option. For those with only a few plants or a small garden, hand removal is a realistic solution. Simply flick them into a bucket of soapy water. There are traps available on the market that lure the beetles with sex pheromones and floral scents. These traps should be avoided because they lure far more beetles than they can kill. This will leave you worse off than if you hadn’t done anything at all. Rachel and I are seriously considering covering our plants with horticultural netting next year. Japanese beetles are here to stay, but don’t give up on gardening. Gardeners on the east coast have learned to deal with them for nearly 100 years. So will we.
Rachel and Ivan Minnis are avid gardeners. They live in Leavenworth. For more information, visit The Minnis Rose Garden on Facebook. Contact them at firstname.lastname@example.org