We know you’re dealing with beetles invading your space, potentially putting health and property at risk. If you need help identifying and eliminating the infestation at the source, connect with our recommended local professional near you.
Blister beetles can cause irritation on your skin and be deadly to your pets and other animals in your home. In this article, we discuss some ways to get rid of them.
Blister beetles are a common pest found in gardens and fields.
They are toxic pests because they release a blistering agent when injured or crushed, which can cause blisters if it comes in direct contact with the skin.
These pests are harmful to humans as well as to your plants and crops.
There are several ways to get rid of them, manually and using insecticides. I will discuss these in detail in the following article.
What Are Blister Beetles?
Blister beetles are part of the Meloidae family of insects.
They are called blister beetles because of a chemical called cantharidin that comes out of them and causes irritation and blisters on the skin when you touch them.
What Do They Look Like?
Blister beetles are usually between 3/4th to 1-1/4 inch in length.
There are many species of blister beetles, of which only a few are found in the US. Most have an elongated cylindrical body, a short thorax, and a wide head.
They are soft-bodied insects.
Blister beetles may also come in several colors, such as ash gray, brown, black, and green. You might also spot striped blister beetles or those with spots.
Where Are They Found?
Blister beetles are commonly found all across the US, South and Central America, and the West Indies.
Moreover, grasshoppers are the main prey for blister beetles. Hence you will find them wherever you find grasshoppers, which is gardens, parks, and other open areas.
What Damage Do They Cause?
Blister beetles can feed on crops and flowers and cause a lot of destruction. When they feed on flowers, it stunts the plant’s growth as it is unable to produce fruit.
Eating blister beetles can be fatal for animals because of the toxins they secrete.
They especially endanger horses and other livestock that often feed on alfalfa hay.
Blister beetles are very common in alfalfa fields, so horse owners should be particularly careful to inspect the hay first.
A large amount of cantharidin and blister beetles consumed even accidentally can cause inflammation, blister beetle poisoning, and even death in animals.
Are They Dangerous To Humans?
As we discussed above, when crushed or injured, blister beetles produce a toxin known as cantharidin.
When it comes in direct contact with the human skin, it can cause irritation and blisters.
If humans ingest them accidentally, it can cause gastrointestinal issues and harm the urinary tract.
How To Get Rid of Blister Beetles Through Natural Ways?
If you find a blister beetle infestation, it is best to use natural and organic ways instead of chemical treatments to remove them.
Diatomaceous Earth
One of the most common and well-known products used is diatomaceous earth (DT). It’s a powder version of a soft, siliceous sedimentary rock that occurs naturally in the environment.
Sprinkling DT near your plants will kill the beetles and prevent new ones from infesting the plants.
Oyster lime shell
You can also use oyster lime shells to repel the blister beetles. While not as effective as DT, you can definitely use it as a preventative measure before planting.
Remove Manually
You can also manually clear the beetles by picking them out of your garden.
However, do not forget to wear gloves if you choose to do this. If you injure or crush them by mistake, the toxins they secrete can irritate and cause blistering on the human skin.
Once you pick the bugs, collect them in a bucket and spray soapy water to kill them.
Neem Oil
You can also try a homemade mix of neem oil in about a gallon of water and some liquid soap.
Spray on the bugs directly and ensure you cover them completely because blister beetles tend to trick you by pretending to be dead.
The neem mixture interferes with the beetles’ need to feed and makes them sterile, stopping reproduction.
Cover Your Plants
Another effective way is to use row covers for your plants. You can either use framed screens or plastic sheeting.
The ideal time to put down these row covers would be after you plant your saplings and before it’s time for pollination.
Birds
Birds are major predators of insects, and it’s no different for blister beetles.
Attracting birds to your gardens with bird feed and water will ensure they pick blister beetles from your plants.
Keep Out Grasshoppers
Blister beetles (more specifically, their larvae) love feeding on grasshopper eggs and weeds such as pigweed, ironweed, and ragweed.
The adult beetles feed on fully-grown grasshoppers.
Keeping these weeds and grasshoppers out of your garden automatically keeps blister beetles out.
Using Chemical Methods For Blister Beetle Control
Please try to use natural and organic ways and products to eliminate garden pests.
However, if the infestation is very strong, only a chemical treatment will help you deal with it.
Spinosad sprays are the most commonly used chemical treatment to eliminate blister beetles.
Spinosad is a biopesticide that will kill blister beetles within 24-48 hours.
It also breaks down into harmless ingredients after two days of exposure to sunlight. This makes it safe for other animals and birds.
However, make sure you keep it away from the water supply.
Group 1 and 3 insecticides, commonly known as Carboryl, lambda-cyhalothrin, and gamma-cyhalothrin, are also considered effective when dealing with blister beetles.
Do not use these when plants are in full bloom, though.
How To Prevent Blister Beetles From Coming Back?
Blister beetles tend to feed on pigweed, ironweed and ragweed.
By maintaining your garden/field and keeping these plants from growing, you can make sure blister beetles stay away from your plants.
Bug Control Recommendation Tool
Grasshoppers are a delicacy for blister beetles. If you spot several grasshoppers in your garden or field, it’s best to inspect the grounds for their eggs as well.
The larvae of this bug feed on grasshopper eggs, and the adult blister beetles feed on adult grasshoppers.
So, if you wish to prevent a blister beetle infestation, ensure that you keep weeds and grasshoppers at bay.
Frequently Asked Questions
How do you get rid of blister beetle infestation?
There are several natural ways to get rid of a blister beetle infestation.
For example, you can use diatomaceous earth or oyster lime shells on them.
If there are only a few, you might also pick them up one by one (with gloves protecting your hands).
After that, just put them in soapy water, and they will die off automatically.
Neem oil is another good way to get rid of these pests.
What are blister beetles attracted to?
Blister beetles are attracted to light, especially ultraviolet (UV) wavelengths. This means that they often congregate around artificial lighting sources at night.
They also feed on grasshoppers and other small insects.
Blister beetles are most active during the warmer months of the year and can be found in large numbers in fields after sunset.
Why do I have blister beetles?
Blister beetles are a common pest problem that can occur in gardens and agricultural crops.
They feed on plant material such as leaves, stems, and flowers. When populations get too high, they can cause serious damage to your plants.
In addition to feeding on the foliage, blister beetles produce a chemical when disturbed that is released from their bodies, causing blisters and sores.
This chemical irritates other organisms, including humans, and can cause discomfort and irritation if handled without proper protection.
What happens if you touch a blister beetle?
Touching a blister beetle can cause skin irritation or dermatitis due to its toxic chemicals called cantharidin.
These chemicals are released as a defense mechanism when the beetle is disturbed.
Cantharidin causes inflammation and blisters with contact, hence its name.
Some people have experienced itching, swelling, and redness on areas of skin exposed to the bug’s exoskeleton.
This may last anywhere from a few hours to several days, depending on the severity of the contact.
You also should be aware that these beetles also release a foul odor when agitated as another defense mechanism.
Wrap Up
Blister beetles are garden and crop pests that secrete toxins harmful to animals and humans. They can also destroy flowers and vegetables by feeding on them.
There are several manual and chemical ways to get rid of them. You can use diatomaceous earth, oyster lime shell, and neem spray as natural repellants. You can weed them out manually too.
In terms of pesticides, you can use spinosad sprays to kill a blister beetle infestation.
Thank you for reading!
51 Comments. Leave new
I have lots of these bugs around my back porch almost always around my wood in the same spot. As soon as the weather warms up just a little bit they start coming out.(around march). By lots I mean a couple a day. At first I thought they were some sort of ant. A little research proved me wrong, should I be concerned at all for any reason? I have never seen them before moving here.(south west Michigan)
I was wanting to know if these blister beetles bite humans and what it would look like?
My husband was in New Mexico this past week and on his arm he has what looks like scratch
marks. Please respond at the above e-mail address a.s.a.p. I need to know so he can get treatment.
Thank you!
I was wanting to know if these blister beetles bite humans and what it would look like?
My husband was in New Mexico this past week and on his arm he has what looks like scratch
marks. Please respond at the above e-mail address a.s.a.p. I need to know so he can get treatment.
Thank you!
We do not know of Blister Beetles biting.
They do not ‘bite.’ They do release chemicals that cause a chemical burn (skin blisters) as their self defense. Teach children and pets to avoid them.
Blister Beetle sighting in NORTHERN Arizona, Chino Valley, elevation approx. 5,000! We have an overnight appearance of half a dozen in the grasses around our livestock pens. High desert, mid-monsoon season.
I just saw this bug in Texas (Dallas/Ft. Worth area)! On the web, it talks about northeast U.S. and Canada…what’s it doing down here??
Without a photo, it is difficult to be certain of your beetle’s identity. There are other green beetles with red legs found in Texas, including the Bumelia Borer.
Saw one of these fellows at the old Fort Wingate Army Depot near Gallup, NM in August
We are envious of your sighting. We have never seen either species in its preferred habitat.
I saw one near Navajo Dam in Northern N M last weekend which is why I started looking for NM beetles. Cool! It was very dark red with black stripes.
I just saw one that looked almost the same in Abbotsford BC, except that it was not metallic but more of a solid red-purple and black.
What a coincidence, I found the exact same bug walking in the Sierra Los Filabres, Almeria, on Tuesday.
Thanks for the i.d.
Thanks for the report.
We have an infestation of these beetles in Moriarty, NM.. 45 miles south of Santa Fe, 40 miles east of Albuquerque. First time in 18 years living here that we have seen them.
Just saw a couple of these critter on my walk this morning in Aztec NM.
Saw a bunch at Aztec ruins a few weeks ago ( early September 2016)
These are NOT blister beetles…they are very common in New Mexico and as a child we used to play with them all the time, they do not bite or blister….they love sucking the juice from green tumbleweeds, and we used to see hundreds of them all over tumbleweeds patches.
According to BugGuide, this is a member of the Blister Beetle family, and it is possible that it is not a species that secretes cantharidin.
Saw two today while walking in the mountains and valleys between Murcia and Succina . Now identified . Thanks
We found dozens of these beauties on a single low shrub in Grasslands National Park in mid June. They were obviously in a mating swarm (?). We could find them on no other similar shrubs any where in the park for the rest of the week. Lots of good pictures. Amazing! Sorry, don’t know what they are.
I have a huge population of them in Southeastern Nebraska. They are eating all the foliage on my potato plants. No sign of grasshoppers.
I have just captured five of the blister Beatles in snowflake Arizona dought they are harmless they have a stinger on their rear end and while meowing the lawn
Just found a beetle at work in pecos, texas. Black ant head and black cone shaped body black with red stripes.
Saw large numbers (30+) of the species hiking in the hills near Itrabo today. Thx for the help to ID these marvellous critters 🙂
Just found one in my yard in Medicine Hat, AB, Canada.
I live about 60 miles south of Gallup, NM at about 7,400 elevation. These bugs are very common here. I see them all around my yard late spring to early winter.
Another study about blister beetles and cantharidin in Spain:
https://doi.org/10.1093/zoolinnean/zlw016
Thanks so much for this link.
I just saw one on the Homestake mil site today
I saw several of these last week at Chaco Canyon and Aztec Ruins
Found one 15 miles north of Heber AZ. Approximately 5800 ft elevation.
These were clustered on weeds in Gallup, NM. In Sept.
Found one in my yard in Las Cruces, NM. Beautiful.
Saw one at Hubbell Trading Post in Arizona in September 2007 (have a labeled photo) and “more linebacker beetles” somewhere around Chinle, AZ area. Maybe the Chaco Canyon or Taos area too but my notes aren’t clear for that.
Found one of these beetles on my False Indigo in Winkler Manitoba. June 13, 2018
Check out this link
http://entomology.ca.uky.edu/ef102
I found one on my deck! It was on my downstairs deck a few days ago and on my upstairs one this morning! I hope it is the same one. Anyways after finding out, it can kill a horse if ingested
I contained it immediately just in case my dog got to it. Pretty little thing. Careful when handling this as the toxins can give you a blister if you touch it or crush it with your bare foot.
July 5/2018 Calgary Alberta Canada
Check out this link
http://entomology.ca.uky.edu/ef102
I found one on my deck! It was on my downstairs deck a few days ago and on my upstairs one this morning! I hope it is the same one. Anyways after finding out, it can kill a horse if ingested
I contained it immediately just in case my dog got to it. Pretty little thing. Careful when handling this as the toxins can give you a blister if you touch it or crush it with your bare foot.
July 5/2018 Calgary Alberta Canada
I saw this beetle on my way to canyon de Chelly 40 miles east of Kayenta Arizona on Monday September 3 2018. Moving fast probably in NM by now.
Megetra vittata:
http://www.meloidae.com/en/pictures/41004/
Megetra vittata:
http://www.meloidae.com/en/pictures/41004/
Bluewater Village area, NW NM. I’ve seen these ever since I was a kid, used to play with them and never got blisters or burns from their orange secretions. We call them carrot bugs.
My husband found one today in Sanders AZ near the New Mexico border 40 miles away from Gallup NM
Saw some today in Santa Fe NM
I work at a school in Albuquerque, NM. I have worked there for 8 years and this is the first time I have seen them. I saw 2 this past week. I had to flick one off a little girl’s backpack. The school is butted right up to the Mesa.
I live in Taos, NM, and had the black variety of the Red and Black Blister Beetle living in my hair for 3 days. Finally fell out when I washed my hair so got a good look at him then. The beetle apparently fell onto my head when I was cutting back the flower canes in my iris bed. At first I thought I had mosquito bites on my neck by rear hairline….had the same reaction. Woke up the next morning with A LOT MORE bits on face, around back of hairline, in inside corner of eye, and in scalp. By this time, I didn’t know what bit me but they were painful plus my eye was sealed shut. As I slept that night, awoke to more bites plus outside corner of other eye. It was when I washed my hair that day that the culprit fell out. Spent another 5 weeks trying to identify the beetle. In the meantime I had 44 bites on head — 22 being on face — all left goodly large sores. Thank goodness for pancake makeup but eyes were the worse. Have apptmt with eye doctor soon since still have problems with eyes but took almost 3 months for sores to heal. Very nasty bug. Will have to look for it in my bearded irises come spring.
Just spotted one in Glasgow Montana!
Lytta subgenus Poreopasta, but I don’t know the exact species. Maybe Lytta cyanipennis.
Much appreciated.
On August 15, 2021, saw 2 of these in a 50 ft radius while in the desert 25 miles east of downtown El Paso,TX. They appeared after heavy rainfall (4 inches in a week) during the monsoon season.
I saw many blister beetles when I lived in Chino Valley AZ.