The blister beetle belongs to a family of insects called Meloidae, which consists of over 2,500 different species. When injured or crushed, the blister beetle secretes a toxin called cantharidin, which destroys tissue so effectively that it is one of the main ingredients of common wart removal products.
If swallowed, cantharidin can cause major damage to the urinary tract and gastrointestinal lining, and at high enough doses (four to six grams), it can even be fatal. Blister beetles have been linked to the death of horses and other large mammals. As if the toxicity of the pest wasn’t enough to scare you, blister beetles are present a terror to flowers, veggies, and pretty much anything else you might want in your garden.
Precautions should be taken to avoid infestations, and crops should be monitored and treated carefully once beetles are thought to be present.The bug population will quickly grow to unmanageable levels if a gardener does not contain the problem and deal with it swiftly once they recognize infestation. There are plenty of things you can do to keep these devilish, derelict, and downright deviant garden thugs from taking over your beds: Just stay vigilant, and be careful. Blister beetles are actually toxic enough to hurt the gardener as well as the garden.
Get Rid of Blister Beetles Manually
Garden pests such as the blister beetle are unwanted guests in any garden. They are known to decimate crops if left unchecked and can come on in swarms and can inflict their damage in a hurry when in large numbers. In home gardens, however, it is often enough of a maintenance maneuver to remove them by hand when you spot them. Due to the toxicity of the blister beetle, gardeners will be wise to always handle these beetles while wearing protective gloves, like these a <href=”https://www.gardeningchannel.com/garden-genie-gloves/”> Garden Genie Gloves.
Knock the pests into a small container filled with soapy water. These beetles are not above playing dead, so if you don’t get them into your container, scoop them up off the ground afterward to prevent further spreading.
Diatomaceous Earth
Gardeners can keep the numbers of blister beetles in the garden to a minimum by spreading diatomaceous earth (also called DT) in the general vicinity of plants threatened by blister beetle attacks. Diatomaceous earth can also be used as a barrier in small pots and raised garden beds. DT not only kills the blister beetles but also repels and drives away future beetles.
Oyster Lime Shell
Oyster lime shell, or OLS, is another effective blister beetle repellent. It won’t kill off an infestation like diatomaceous earth will, but laying out a treatment at the start of each growing season is a great preventive tactic to keep beetles from ever targeting your garden to begin with. OLS can also be used as a barrier in small pots and raised beds.
Spinosad
While we generally recommend avoiding chemical treatments and going as organic as possible when treating your garden for pests, like these ten organic pest control methods. Blister beetles are sometimes so powerful and persistent that insecticides can be the most effective option for getting rid of the invaders. Sprays containing spinosad are your best bet because spinosad breaks down into harmless ingredients within a day or two. Just be careful not to endanger your honeybee neighbors in the process and spray during the heat of the day, when bees are not present.
Things to Avoid to Prevent Blister Beetles
Sometimes the best preventive treatments involve what you don’t have in your garden as much as what you do have. Blister beetles are quite fond of pigweed (a type of amaranth), as well as ironweed and ragweed. Keep these weeds out of your garden entirely, and you will have a much better chance of avoiding blister beetle infestations.
While it is highly recommended that you avoid having these plants in the garden at all to avoid blister beetles, some gardeners choose to keep pigweed around to keep the blister beetles distracted and feeding on a useless weed while leaving the herbs and vegetables they want to harvest untouched. This is a proven method, but it’s still a large chance to take. When those beetles run out of pigweed, they are going to start gnawing on something else nearby in your garden. Best to avoid their presence in your garden altogether if possible.
If you start to see a large influx of grasshoppers, you might want to inspect your garden beds for other new arrivals. Blister beetle larvae feed on grasshopper eggs. While this relationship is not much of an issue when the beetles are still in larval form, once they become adult beetles, fully formed and fat off of grasshopper eggs, you have a serious problem on your hands. Use semaspore bait or other grasshopper control methods to keep grasshoppers away, and in turn, drive blister beetles away in search of more plentiful food sources for their offspring.
Things to Attract to Control Blister Beetles
Birds are a gardener’s best friend when dealing with blister beetle infestations. Use these methods to attract birds and wildlife. Birds pluck blister beetles right off of plants, and, if persuaded to infiltrate your garden in large numbers, birds can decimate massive beetle infestations. Attract birds and beneficial insects into your garden by planting colorful blooms and nutritious plants, while avoiding harmful chemical sprays that could hurt birds or drive them away.
Though it’s impossible to decide exactly which birds and insects are welcome in your garden and enforce the rule, you can decide what to attract and what to dissuade from joining your merry gang of green-leafed friends. The lineup of your garden is completely up to you, Don’t allow garden pests to dictate to you what you should have in your garden, but keep any suggestions to help deal with them in mind when choosing your crops.
Want to learn more about getting rid of Blister Beetles?
University of Florida covers Blister Beetles
Mother Earth News covers Control Blister Beetles
Planet Natural explores Blister Beetles
Matt Gibson is the Sales Director and Project Manager for Russell Gibson Content. He is also a freelance writer, poet, lyricist, rapper and composer. His gardening expertise is centered around herbs, cacti, succulents, and carnivorous plants.
While gardening in Illinois, I had an Infestation of blister beetles which were really fond on my potato plants. As an organic gardener, I wanted to avoid insecticides so I searched for alternatives. I learned that a drop of their discharge administered to the face of a beetle would kill it. So, I collected the beetles (Baggies for gloves), put them in a blender with water and sprayed the potatoes with the solution. No bugs for 2-3 weeks. When they returned, I repeated.
This is the craziest story I have ever heard!!! I am dealing with (or was dealing with) Blister Beetles on my potatoes as well! I tried DE but that didn’t seem to do much. So I tried vinegar and soap in a spray bottle with water. That worked, but I think the heat of the day or just the spray itself fried the rest of the greens. But this is good to know and I will remember it for any future infestations!! Thank you!!!
I have these nasty creatures in my backyard (Connecticut) live near a farm and last year after purchasing this home, the yard around this time of year was filled with these blister beetles
I called local lawn care companies and no one can help me. I will try the soap and vinegar to spray them. I no longer have a backyard, my dog will have to use the front lawn to do his business until the winter or until I find a solution! Thank you for your posts.