How to Get Rid of Japanese Beetles in Your Yard

I remember that the first time I became aware of Japanese beetles was around the year 2005 when my husband was traveling for a couple weeks, and I discovered that the leaves of his prized canna lilies were getting more holes in them each day.    I finally went out to look at the cannas more closely and found many bronze and green iridescent beetles flying around the plants and munching away on the leaves. 

I told my husband about them later that night when he called, and he knew exactly what they were - Japanese beetles.   He told me "just pick them off and squish them".....but....I'm squeamish about squishing bugs!   So I did some research and found a surprising number of safe and natural ways for getting rid of these colorful but destructive little beasties.

The presence of Japanese beetles on your plants will draw in more Japanese beetles, from certain pheromones they release.   If you can get rid of the beetles that are already present, then less new beetles will be attracted to your plants.

Here are a few simple methods for getting rid of Japanese beetles.

Pick them off and squish them

Yes, this is the simplest, lowest tech way to get rid of Japanese beetles if you're not squeamish, and if there aren't too many (you can decide what is too many for you). Do this every day while Japanese beetles are present in your area. 

Japanese beetles are active for 4 - 6 weeks during the summer, but they may be present for only part of that time on your plants.

A variant of this method is to vacuum them off your plants.  Go carefully so as not to further destroy your own plants!   And empty the bag or cannister afterward, otherwise the dead bugs will start to smell.

Flick them into soapy water

This turned out to be a very simple and effective method for me to get rid of the Japanese beetles on my husband's canna lilies.

This is a variation of picking them off, but I didn't have to squish them and I didn't even really have to touch them except to flick.

I used about a tablespoon of dish soap in 2 cups of water in a plastic bowl.   With bowl in one hand, I flicked the Japanese beetles into the bowl with the other hand.   You can brush them into the water with a gloved hand if you don't want to touch them at all.   It also works to tap the leaf with the bug over the soapy water.  

The Japanese beetles die in the soapy water because it destroys their cell membranes, and their bodies dehydrate.

Spray with a soapy water mixture

 Put the soapy water into a spray bottle and spray the Japanese beetles and the surrounding leaves.  The Japanese beetles will die from being suffocated from the soapy water.

A good proportion to use is one to two tablespoons of liquid soap to one quart of water.  I use dish soap but any liquid soap will do. 

You can also add strong smelling roots or spices, such as garlic, onion, hot pepper, or horse radish to your soap mixture to repel further beetles (as well as other insects and deer and rabbits).

It works best to spray during the warmer times of the day when the beetles are more actively eating.

Repeat daily while the Japanese beetles are present.

Spray with a dead Japanese beetle mixture :-)

This is perhaps ghoulish but very satisfying!   Save some of the beetles that you've been squishing or drowning,  wiz them up in a blender (you may want to use an old blender for this!), strain them so your sprayer doesn't get clogged, add to a couple cups of water (your soapy water is fine), and spray your plants.

Apparently Japanese beetles are deterred by the scent of their dead brethren on plants!  

I've also heard that leaving your dish of dead Japanese beetles in soapy water next to your affected plants will deter live ones.  If this is so, it's easier than wizzing up the dead ones.  

Spray with neem insecticides

Neem oil, or neem seed oil, from the tropical neem tree has compounds that mimic the insect hormones that control eating, breeding, and molting.  Spraying Japanese beetles and the plants they're on with a neem product doesn't kill the beetles outright, but will inhibit their eating, mating, and egg-laying.   Therefore your plants don't get eaten, and you've stopped some of the next generation of Japanese beetles from going through their life-cycle.

Neem affects chewing and sucking insects including Japanese beetles -- both the larval grub stage, and the adult stage.   Only insects that eat the sprayed leaves will be affected.   Neem has to be ingested to work, so  neem doesn't affect beneficial insects like bees, because they don't eat leaves.   The exception is if you spray the bugs, including beneficial insects, directly, then the oil spray can cover and suffocate them.    So if you want to use a neem spray, do it in the early morning or evening when the beneficial insects are less active.

There are a number of Japanese beetle traps on the market.  While these are highly effective in luring in Japanese beetles, they often bring in many more beetles to the area than would otherwise be present.  A number of gardening experts think these traps do more harm than good.  They suggest that if you do use traps, place them well away from gardens and plants that would be affected by Japanese beetles.