The story goes like this: in the early 1900s Japanese beetles were accidentally introduced into the American ecosystem via shipments from Japan. Unfortunately, these green and copper-colored beetles have very few natural predators in our country, which has led them to become one of the most widely spread and damaging garden pests in the U.S. Today.
Most active during the warmest summer months (mid June to late August for adults, fall and late spring for larvae), these beetles and their larval grub form can wreak havoc on your lawn. The adult beetles “skeletonize” nearly all forms of plant life, while their younger grub counterparts consume grass and other roots from below the soil. Because Japanese beetles eat in groups and feed from both above and below the soil, they can devastate entire lawns and gardens in no time. If Japanese beetles are destroying your lawn, or you’re just looking for ways to keep that from happening, here are 9 Natural Ways to Get Rid of Japanese Beetles
The tried and true method of handpicking Japanese beetles from your lawn or garden is still the most effective approach to controlling these pests. It can take some time, but the effect it can have on the health of your plants is well worth the effort.
For best results, do this in the early morning, when Japanese beetles are most active. Using gloves, pluck the beetles from grass and other plant life being careful not to squeeze or crush them (doing so could attract more beetles). Dispose of them by dropping them in a bucket of soapy water (2 tablespoons of liquid dish soap per 1 gallon of water)—this is one of the most humane ways to eliminate Japanese beetles.
Keeping guinea fowl around your lawn & garden is a proven way to limit not only Japanese beetle populations, but that of ticks and other pests as well. However, not everyone wants to keep these loud birds as pets. In that case, finding ways to attract ducks and other birds to your yard will do the trick.
Spraying your entire lawn with a soapy mixture of 2 tablespoons dish soap to 1 gallon of water will help force Japanese beetle larvae to the surface, which in turn will attract hungry birds (this should be done in fall and late spring, when Japanese beetles are in the larval stage of their life cycle). Continue this process weekly until no further larvae emerge from the soil.
Japanese beetles are most attracted to rotting and overripe plants, so keeping a healthy lawn and garden is key. Promptly remove diseased or otherwise dying plants, trees, fruits and vegetables before they attract additional beetles to your yard. Harvesting plants before they become appetizing to beetles is also crucial.
Row covers allow air, sun, water and other essential elements to reach your plants while keeping Japanese beetles out. Remember: To remain effective, the edges of the cover must be flush with the ground, or otherwise firmly sealed. If Japanese beetle grubs have already infested your soil, this method is not for you, as it will only serve to trap the beetles inside the cover with your precious plants.
One of the greener options for Japanese beetle control involves introducing parasitic roundworms into the soil. Also known as beneficial nematodes, these organisms can devastate soil-dwelling pests like Japanese beetle larvae. Once they’ve located and entered a host, these nearly microscopic worms release a bacteria that’s deadly to the young beetles. After killing their host they move on to another beetle, reproducing in the process.
For best results, introduce nematodes into your soil in late August or early September to attack the next cycle of beetles for the following year (while this is the optimal approach, nematodes can be added to the soil at any time, so long as the soil is sufficiently watered).
Note: the nematode species Heterorhabditis is said to be most effective against Japanese beetles. The nematode pest control method targets larvae, not adult beetles. Beneficial nematodes can typically be found at your local home & garden store.
While Japanese beetles enjoy eating a wide array of plant life, certain types are particularly attractive to these devastating pests. Inundating your garden with Japanese Beetles’ favorite food sources is just asking for trouble. Limit such plants as much as is reasonably possible. For a list of Japanese beetles favorite meals, click here.
Drop cloths can be highly effective at cutting down Japanese beetle populations. At night, cover your plants with a sufficiently large drop cloth. In the morning when beetles are most active, remove the cloth and dispose of the attached beetles using the aforementioned bucket of soapy water.
Most Japanese beetle traps are ineffective, usually only serving to attract additional beetles to your lawn & garden. However, a can of fruit cocktail can help quickly remove active beetles from your yard. First, ferment the cocktail by leaving it in the sun for a few days—this will make it more attractive to beetles. Next, place the can on top of a brick or bricks stacked inside a pail filled with water (it’s advisable to keep this trap far removed from the plants you’re trying to protect). The cocktail will attract the beetles, the water will drown them. It’s that simple.
Mix 4 tablespoons of dish soap with a quart of water inside a spray bottle. This simple solution makes for a great, all natural Japanese Beetle pesticide. Spray on any beetles you see on or around your lawn & garden.