Japanese Beetles

Japanese beetles will damage trees, shrubs, fruits and roses

Japanese Beetles have made an earlier arrival this year. Gertens experts have the solution to control these pesky insects. Japanese Beetles can be destructive toward plants in both their adult beetle stage and in their grub larval stage.

Japanese Beetles are an incredibly destructive plant pest found throughout most of the eastern United States, stretching westward toward states along the Mississippi River, including Minnesota. The Japanese Beetles can be destructive toward plants in both their adult beetle stage and in their grub larval stage. As adults they damage plants by feeding on foliage of a multitude of trees, shrubs, fruits, ornamentals, flowers, vines, and vegetables.

Some of the more notable plants they feast on in the Twin Cities metro area are; rose bushes, grape vines, birch and linden trees, and raspberries. The damage can be identified by skeletonized leaves (eating the area between a leaf's veins) and large holes in leaves, this can often appear to be a lacey texture. The Japanese beetle grub lives in the soil and causes destructive damage by eating the roots of many plants including turf grasses.

Adult Japanese Beetles are most commonly found during the late spring through late summer. While female beetles are feeding, they will periodically leave the plants and lay eggs, usually into the turf. One beetle can lay upwards of 50 eggs a year. These eggs then hatch into grubs around midsummer which begin to feed on the roots of turf grasses and other plants.

Before the first frost, the grubs will bury deeper into the soil and remain inactive throughout the winter. When the ground thaws in the early spring, the grubs will move closer to the surface of the soil and begin feeding on roots again until they begin to pupate in late spring. Then, in about two weeks the pupae become adult beetles and they emerge from the ground and begin consuming plants again. This completes the average, one year life cycle.

If Japanese Beetles are bugging you, consider one of our many different solutions to help control the infestation.

One solution is spraying plants that are already infested with the adult beetles with an insecticide. We have several effective sprays for this type of treatment. Bonide makes a product simply called Japanese Beetle Killer; which is a natural pyrethrin based insecticide for use on vegetables, flowers, ornamentals, trees & shrubs. Another effective spray treatment is one more product from Bonide called, Eight Insect Control. Eight Insect Control kills Japanese beetles on contact and also has a residual effect, lasting up to a week or more. We also have a few options that can be used around your fruits and

vegetables and can both be used up until the day of harvest. One product is Natural Guard Insecticidal Soap.The other product is from Fertilome and is called Triple Action Plus.

Another product for control of the adult Japanese Beetle is Green Light Tree & Shrub Insect Control with Safari, a systemic insecticide. This granular product works by absorbing into the roots of a plant and protects it internally against insects that feed on the tree. To apply it, simply measure out the correct amount of granules depending on shrub height or tree trunk diameter and apply to the ground beneath the plant. This will then absorb into the roots and get taken into the entire plant to protect it for an entire year against Japanese Beetles and numerous other damaging insects.

Green Light also has another product to work in controlling the grub stage of the Japanese Beetle.

Their Grub Control with Arena kills grubs all season long and can be applied to lawns, landscaped areas, flower beds, and around trees and shrubs. If applying insecticides isn't your thing, or if you are just looking for an easy way to help fight the Japanese beetle problem, look no further than using our Japanese Beetle BaggerTrap by Bonide. This trap attracts beetles with a dual floral/pheromone lure into a plastic, hourglass-shaped bag. The lure effectively attracts beetles from a surrounding area of up to 5,000 square feet. The trap might attract more Japanese beetles to the immediate area, so be sure to hang it about 15' away from any trees or plants you are trying to protect.

If you have any further or clarifying questions about Japanese Beetles or other insect or plant related issues, please give us a call at 651.450.1501 or stop in to our Lawn & Garden department and we'll be more than happy to help solve any insect or yard and garden problems.