Have you started noticing colorful, metallic green insects flying around your plants? Japanese beetles have just begun their normal Summer feeding of trees and shrubs. The sight of large numbers of feeding insects can be discomforting for homeowners. Their destruction can be rapid and completely skeletonize leaves. The Japanese beetles normally become present in large numbers around the 4th of July through most of August. This is when the adult beetle feeds and deposits eggs in the soil that will hatch the following year.
The Japanese beetle does have favorite host plants, including Roses, Linden trees and many fruit tree varieties but unfortunately their feeding can seem indiscriminate at times. Although some years have lower numbers of beetles than others, there is no indication that they are going away. This is a pest Illinois will battle for years to come. Fortunately many trees and shrubs will recover from the feeding frenzy of the Japanese beetle, but it’s beneficial to treat plants that are experiencing heavy infestations, especially if it’s year after year. A tree or shrub that has experienced leaf damage for more than 3 years in a row can become vulnerable and start to decline.
Treatment for Japanese beetle is most effective when large numbers are present. Sprays will kill the adult beetles present and generally have a 7 day residual effectiveness. Since their feeding happens so quickly, it’s important to react in a timely manner. Timing is very important in the treatment of this pest. Spraying too soon may not eradicate enough of the beetles and spraying too late may not save the plant leaves before they are completely consumed by the Japanese beetles.
Are Japanese beetles invading your yard? Contact the Plant Health Care Department at KTS and we will help you find a solution.