10 Natural Ways to Get Rid of Blister Beetles in Garden

In the family Meloidae, blister beetles produce a chemical called cantharidin. This chemical is toxic to humans and animals and may cause dehydration, blisters, and even renal failure if swallowed.

If eaten by an animal (even one as big as a horse), it only takes around 25 beetles to kill that animal [1]. With this in mind, it’s imperative that you properly identify these pests and get rid of them as soon as possible.

Identification

All blister beetles are medium to long, 3/4 to 1.25 inches, with narrow bodies [1]. They have broad heads, long legs, and long, thin antennae that are beaded.

They also have soft wing covers that are flexible. These beetles will travel in groups, and when disturbed, they will simply drop to the ground and hide.

How to Get Rid of Blister Beetles Naturally

Below are some home remedies and natural solutions to get these harmful insects out of your garden.

1. Handpick

One inexpensive way to control blister beetles is to pick them off. However, it’s best to wear gloves.

Also, if you don’t grab it before it sees you, the beetle may fall to the ground beneath the plants it’s feeding on or get lost in the hay.

Therefore, make every effort to pick up the beetle from wherever it is and put it into a container or bucket filled with soapy water.

But don’t squish it; otherwise, you could end up with cantharidin all over your gloves, which, in turn, could transfer to your bare skin.

2. Diatomaceous Earth (DE)

Apply diatomaceous earth at the base of the host plants as well as around stones, and anywhere else you might think these beetles would lay their eggs.

The sharp edges of this product will cut up the underside of the beetle, later killing it.

3. Oyster Lime Shell (OLS)

OLS is another natural powder to help control blister beetles. It won’t kill them, as it’s more of a repellent, but you can use it as an excellent barrier in pots and raised beds.

Oyster lime shell is also good for enriching soil quality and balancing soil pH levels.

4. Spinosad

Spinosad is an excellent blister beetle treatment because it kills them in 1 to 2 days.

Though many consider it a chemical rather than a natural way to get rid of bad bugs in your garden, we included it on this list because that’s not the case.

That’s because spinosad is derived through the fermentation process of a soil bacterium, which makes it perfectly natural. Moreover, it’s OMRI-listed.

Spray this blister beetle treatment directly on the critters. The product has to make direct contact with the bugs to work properly.

5. Birds

This is one of the best ways to get rid of blister beetles organically. Many birds love beetles. They’ll happily pick them off your plants for you.

Attracting birds is as simple as providing a source of water and an initial source of food until they discover the pests. Certain plants and flowers, like sunflowers and coneflowers, may also attract birds.

6. Row Covers

Row covers range anywhere from simple screens on frames to rolls of plastic sheeting stretched out over rows in the garden.

Install your row covers right after planting but before the adult beetles emerge. However, be sure to remove them when it’s time for pollination.

7. Weed Control

Blister beetles will flock to weeds during bloom. They really like ironweed, pigweed, and ragweed. If you want to keep blister beetles away, get rid of weeds in and around your vegetable garden.

However, some gardeners will keep pigweed (a trap crop) around in the hopes the beetles will feed on it and not on their crops.

8. Repel Grasshoppers

Blister beetle larvae make their meal out of grasshopper egg pods. Therefore, getting rid of grasshoppers is highly effective in preventing an infestation of these pests.

If you see a lot of grasshoppers in your garden or around the house, you may also see more blister beetles around. A little reading will tell you the best ways to get rid of grasshoppers.

9. Bug-Buster-O

If you want the critters to go away without having to whip up DIY recipes, Bug Buster-O is an excellent natural insecticide. Spray it directly on the blister bugs, but be careful not to soak the plant or the soil.

Bug Buster-O can be bought commercially. You can also use it to control other pests like asparagus beetles, bean beetles, and elm leaf beetles.

10. Neem Oil

Neem oil is also a great home remedy for beetle control to help get rid of an infestation.

This all-natural oil coats the body of the adult blister beetle and interferes with its life cycle.

Simply mix it in a ratio of 2 teaspoons (this brand) to one gallon of water with a liquid soap like Castile. Shake well and spray directly on the beetles.

Takeaway

Blister beetles are very prolific when breeding, and they like to travel in groups. This means you can have an infestation before you’re even aware there’s an issue.

By implementing the various prevention methods, you will lower your chances of providing blister beetles with a home.

If, however, you do find the little pests in your garden or hay, the best natural control methods for repelling and killing them are also on the list.

Some of these methods are quite effective when used alone. Others, used in conjunction with some of the other remedies, have done quite a bit to keep these beetles out of the garden and feeding hay.

It all depends on how much work you are willing to do before, during, and after there’s a noticeable infestation.

Images via Flickr/Judy Gallagher and Dendroica cerulea