The COVID-19 pandemic has contributed to a surge in first time gardeners. People have a new incentive to try gardening. Inevitably, home gardeners have questions about plant material, diseases and insect pests. Controlling Japanese beetles is a hot topic and they are the insect pest that gardeners are most concerned about now. This is peak season for Japanese beetles in the Mid-south. Japanese beetle infestations are the scourge of the summer garden. In my opinion, Japanese beetles are the worst pest to have in your garden. They just will not stop eating!
Japanese beetles feed on 300 species of plants. The adults are a serious pest of field crops, flowers, turf, trees, shrubs and vegetables. Grubs mainly feed on the roots of grasses. The adult beetles are currently decimating my roses!
Japanese beetles feed during a six to eight-week period starting in the summer. Japanese beetles can completely skeletonize leaves by feeding on the green tissue between the veins giving the leaves that lace-like appearance. Those leaves will eventually turn brown and then fall off. The damage caused by the adults usually only affects the appearance of the plant. Their feeding can injure, stunt or kill young or unhealthy plants. They can be difficult to manage if their numbers are substantial. Damaged leaves seem to attract more beetles so be sure to practice good sanitation; it is important to remove dead or fallen leaves.
The most important question: how can they be controlled? Handpicking or brushing them into a bucket of warm, soapy water will do the trick. If you remove the damaged leaves, you will reduce the number of beetles that will be attracted that plant. The best time to remove the beetles are early morning or late evening. They seem to be more sluggish during these times.
If you must use a chemical, consider low impact insecticides. Look for products that contain pyrethrins. These are contact sprays. Neem oil may help as long as there is not an excessive infestation. Please read and follow the label on these products. Be careful not to use these products when bees and beneficial insects are present.
This information should arm you with the knowledge to go out and control those beetles. Again, they can be a big problem in the garden. Did I mention they are decimating my roses? Where is my bucket, I have work to do! If you have questions, please contact me at 901-752-1207. Until next time, take care, stay safe and enjoy your garden.
Photo Credits: Julie Morgan; Shannon Hammers