Japanese beetles on roses

A Remedy for Japanese Beetles

In Blog, Gardening, News by Val Thies

The Japanese beetle is an unwanted garden pest causing massive damage to our beloved plants in its adult form and our lawns in its larval/grub form.

The Japanese beetle is not native to Minnesota and has no known predators in its adult stage, making it difficult to get the large numbers of these destructive beetles under control. They are voracious eaters, destroying leaves, flowers, vegetable plants, and fruit trees. You have probably seen one of their meals of skeletonized leaves in your own yard.

Once they are done feasting on your precious plants, the females fly off to lay 1 or 2 eggs in a sunny turf location. Over the course of their adult life, a female Japanese beetle will lay between 40 and 60 eggs. These eggs hatch in August and immediately begin dining on the roots of the turf grass where they were laid. The damage to our lawns by the larval or grub form of the Japanese beetle can be more devastating than the visual unsightly defoliation caused by the adult beetle. As the grubs feed on the roots of grass, they leave irregular shaped brown patches that lift when pulled on. This damage is usually seen in late summer or early fall. Grubs also attract animals such as raccoons, skunks, and moles which dig up our lawns in search of their next meal.

Beneficial Nematodes

So what can we do to manage these pests without the use of pesticides and chemicals? Beneficial nematodes to the rescue. Nematodes are beneficial microscopic insects that travel below the surface of the lawn and attack grubs that are feasting on roots. They kill the grubs in 16-48 hours by locating the grub, entering it and infecting the pest with toxic bacteria and killing it. They produce hundreds of thousands of offspring which then search for more pests to infect.

They are safe for people, pets, and plants. They are a natural and effective alternative to chemical pesticides and have no detrimental effect on non-target species such as ladybugs, earth worms, and other helpful garden insects. Please note: This product doesn’t affect the adult beetles that are currently terrorizing your garden. It will reduce the overall population of beetles. Do not use beneficial nematodes if you have already applied an insecticide to your lawn.

Learn more about beneficial nematodes, including prices and application instructions.

August through September is the time to apply beneficial nematodes to your lawn.  Contact Tonkadale by phone, email or through our online form below to reserve your supply for pickup on or after August 17.