Blister Beetles
Blister beetles do not have a toxic bite or sting, but if you crush one of these pests you can wind up with small blisters on your skin several hours after contact due to the secretion of cantharidin (a toxic compound in their bodies).
Grey blister beetle (top left), Black bister beetle (top right)-photos United Agri Products
Description
Blister beetles have very long thin cylinder-shaped bodies with large heads. They are about 2 cm long (from ½ to 1 inch in length) and relatively easy to identify because of the distinct “neck-like” section between the body and the head. They usually fly around in groups and there are many types of them. They are grey, black and striped with some species shiny black-blue, or black-green.
Habitat
Blister beetles are found in most parts of the US and most parts of Canada. It is the adults that cause most of the damage. Fortunately however they don’t stay around an area too long so the best control is to let them run their course unless infestation is severe. They overwinter as semi-pupae in the soil and emerge in the spring and molt. Adult blister beetles emerge in the summer months.
Life cycle of blister beetle-NC State University
Diet & Damage
Blister beetles eat the leaves and flowers of most plants… peas, beans, potatoes, turnips, tomatoes, many other veggies and flowers. They can defoliate plants in no time. The larva have been known to eat grasshopper eggs so they are somewhat beneficial. In some cases where these beetles are severe on alfafa, farmers must take caution when cutting as their livestock can die from ingesting dead blister beetles. The condition that affects livestock after eating grains infested with these beetles is called Cantharidiasis
Control
1) Hand Pick
Be sure to wear gloves or use tweezers as they can release a substance that causes blisters on the skin. Drop them in hot soapy water. Be sure not to touch them even when they are dead as they can still cause painful blisters on your skin.
2) Keep Weeds Low
Weed around edges of your garden attract blister beetles because of grasshopper eggs. Eliminating the weed problem will help control infestation.
* A word of warning, killing them is not a good option unless you dispose of the bodies. Their poison stays in their bodies long after they are dead.
January 16th, 2011 at 1:23 pm
Sherry, Even if the original blisters were from the bug, I suspect something different–maybe you got the herpes virus into one of the open sores, and you are getting recurrences. It wouldn’t help to get a blood test for herpes, because at your age you have a 90% chance it would show positive for the cold sore virus. (Almost everyone gets HSV-1 eventually, even if they’ve never had a cold sore.)Ask your doctor if he/she would do a herpes culture of the blisters–but it needs to be done the 1st day of the blisters, for best accuracy. If positive, you could take one of the antiviral meds to make it go away faster. I know it’s an unusual place for it, but herpes sores have even been found on the fingers.
January 15th, 2011 at 8:05 pm
I’m glad to hear I’m not alone. Over 50 years ago a blister beetle crawled across the back of my neck. For many years the blisters and pain recurred when exposed to lots of sun. (a large area) I have had small breakouts throughout the years and had another just this week. It begins with pain in my neck & shoulder, then the blisters appear and the pain goes away. I treat with antibiotic ointment but nothing seems to speed the recovery. Anyone else have recurring episodes?
November 28th, 2010 at 9:20 pm
You should go see a doctor,doesn’t sound right.
Good Luck Cahri
November 28th, 2010 at 12:06 pm
I woke up with blisters and a red area that looked like I had burned myself somehow – it blistered and itched during the night and I apparently scratched it and broke the largest of the blisters open and now they have all opened and left red, raw patches of skin but all the surrounding skin looks like it is sunburned. it is hot to the touch but doesn’t look infected. I’ve been treating it with Neosporin and washing the area with an antibacterial soap and so far it hasn’t spread. But it’s painful to the touch and itches like a madman!!! Is there any over-the counter topical treatments that work on the itching?
September 24th, 2010 at 9:26 am
I was “stung” by one of these bugs five days ago and the area is almost cleared up so I must have done something right. Immediately after the bug was on me the site on my inner arm had a very bad stinging sensation. I thought I had been stung and put some Sting Ease product on the site. Within five minutes a blister the size of a nickle and a much smaller blister appeared on my arm. It felt like it was on fire. Over the next 24 hours the blister area grew to about 3 inches in size and was very hot. I treated it with cortizone creme for the severe itching and ice for the heat. The cortizone didn’t seem to help but the ice helped a lot. At about 24 hours after the sting I took Benadryl. This seemed to help also and within 36 hours of the sting the area began to diminish in size, heat and itch. These bugs are nasty. Hope this helps others.
September 14th, 2010 at 4:28 pm
blister beetles can be a really nasty tipe of insect it got into my horses and killed them i was relly really disaponted
September 7th, 2010 at 10:10 pm
Also, forgot to mention that if you do pop the blister’s make sure you’re lying on a flat surface and have an alcohol soaked cotton just below it, because your blisters will keep growing if when you pop them it (liquid) runs down on your skin. That’s why for most people it gets worst because it popped and it affected the rest of the area. Have had our share with these pests.
September 7th, 2010 at 10:05 pm
For those of you looking for safe green ways of getting rid of this pest, consider horseraddish. You put the horseraddish in water or use blender to do this and use it as a spray. This will not harm your garden. I often use it in South Texas as there are many..usually you’ll find the grey ones down here. Hope it works for your type of blister beatle.
September 4th, 2010 at 9:16 pm
Kristi
This does not sound good, and it isn;t blister beetle. Take her to doc right away!
September 3rd, 2010 at 9:09 pm
while preparing to have a yard sale my 8 yr old started crying that something was biting her and when i looked i never found anything—-bug or bite mark—-2 hrs later i looked again and she didnt have blisters but has a mark about 3/4 inch long that looks as if her outer layer of skin was peeled away… does this sound like the “blister beetle” bite?
August 18th, 2010 at 1:47 am
I was just sprayed by a blister bug in the hill country of south Texas. I had large blisters that appeared about 6 hours after. I noticed about 3 hours after the bug was flicked off me a sharp, hot pain in my neck. Later the blisters came. The painful part was before the blisters. I popped them and now I have what looks like 2nd degree chemical burns on my neck. Exposed pink and red dermal tissue in 2 places like the size of a quarter each! Its hurts to take a shower and if my clothes rub the wounds. It has been 3 days now and it sucks! I am putting neosporin on them all the time and hope they go away.
August 17th, 2010 at 6:07 pm
My son had a strange blister on his shin which overnight doubled in size. Took him to the ER the next morning and she said it was probably a blister beetle. prescribed an antibiotic and recommended that we keep the blister covered. I added some neosporin with pain relief for good measure. the blister popped from rough play (he’s two) and i changed the dressing as soon as i noticed and the wound is healing nicely. in addition to the blister he also had a two inch surronding area that appeared red and now looks to be peeling and healing with the original blister site. he is definitely not in pain anymore. a few days ago i found a dead beetle in the laundry while sorting clothes. lord only knows where it came from and how it got into the house. Thanks for the site. I will be extra vigilent while outside now. Bees, fire ants, fire mites and now blister beetles. Come on winter!
August 16th, 2010 at 10:23 pm
My son was recently stung by a blster beetle and I did puncture the blister with a clean needle and wiped the puss like fluid with peroxide and it cleared it, so hopes this helps!
August 16th, 2010 at 4:30 pm
My family and I have gotten quite a few blisters from the grey blister bugs, and the best treatment we have is to pop the blister with a clean pin, apply pressure with a cotton ball to absorb all the discharge, and once its all out, clean it with 90% rubbing alcohol. When its dry put on neosporin. The blister never comes back and it takes about a week to heal. But be sure not to touch any of it with your bare hands, it might spread! Good luck!
August 14th, 2010 at 11:06 pm
I went fishing in Homestead,Fla.,and all night long bugs drove me crazy crawling on the hair on my arms and head.I kept brushing
them off never feeling any pain, probably due to massive doses of
fish attractent I was consuming(Budweiser) and finally gave up about 4 a.m.
I went home showered and went to bed. When I awoke I was covered with blisters. They did`nt bother me and went away in a
couple days or so. A lot of people I worked with knew it was blister bugs that caused the blisters, but in 50 years of living in South Fla. that was th only time I encountered them.
August 8th, 2010 at 10:33 pm
While we were sitting watching a movie in the living room, my 5 year old daughter all of the sudden started crying and showed me her finger, she didn’t know what happened, but her finger started swelling immediately. I thought she may have twisted it or popped it, but you could see a small bite mark on the knuckle. I got up from my chair to look for it, and it was crawling on my chair…a blister beetle! My husband grabbed a paper towel to pick it up. Then he found another one by the front door. Apparently, they were attracted to the front porch light that we had left on, and had crawled under the screen door into the house. We’ve never had a problem with them before, having lived here for 6 years, but at least now I am aware of them out here. I will be using rubbing alcohol to try and dry up the blister. I will let you know how this goes and how long it takes to dry the blister up.
August 8th, 2010 at 9:46 pm
Do not pop the blisters. Protect the area with petroleum jelly and a large band aid. They will heal in less than a week usually. But, the liquid inside will definitely cause other blister where it makes contact. Good luck.
August 7th, 2010 at 1:44 pm
my 4year old just got stepped on a blister bug and it was aweful it just keep getting bigger and bigger. we finally popped it after three days but decide on the 5th day to see his doctor she took a culter and had a infection in it. it was on antibotics and cream for awhile. you can still see the red circle on his foot and it happened over a month ago. next time i wont wait to go to the doctors. im soo glad we didn’t touch the liquid and spread it. im glad to find all the info on this site. thanks it was very helpful and now i know what to look for in the yard and garden.
August 2nd, 2010 at 4:27 am
One of these benighted things crawled across my arm while I was napping back in April and I brushed it off, never having heard of blister beetles or cantharidin. I soon had a row of nasty little blisters three inches long. When they dried and burst they left a scar. Now, three months later, they’ve come back in the exact same place. I am not certain whether it is the result of another bug striking in exactly the same place and manner (unlikely) or some sort of residual effect (unheard-of). If some enterprising young genetic engineer develops a microorganism that results in the extinction of the black blister beetle, I’ll buy him a large bottle of very fine bourbon. I have had no issues with new blisters at other sites, but some relief is achieved by application of ice.
July 28th, 2010 at 9:29 pm
I’m in Kansas City, MO and I must have a huge infestation of them in my backyard garden… typically I’d only run into these bugs down at scout camp near Springfield, MO – never this far north and never AT HOME.
The blisters are extremely itchy, and clothes rubbing on them makes things 10x worse.
I’ve never known these blisters to spread via scratching them, but I’ll have to try not to pop these blisters from now on, it’s probably a good rule to follow.
July 23rd, 2010 at 8:15 pm
In Kansas. Must have gotten the blisters in the black raspberry patch, while picking the berries. Is a long streak of blisters on my arm. I have been applying hand sanitizer on my blisters, thinking the alcohol will denature the venom’s proteins. Not as successful as early this spring, when I got blisters. During the nursing job this spring, I applied green soap (Dawn dish soap) and then wrapped it. It went away within days. Had it also last summer on the back of a knee, treated it with triple antibiotic cream, to no avail. Finally, following a week of blisters, I applied hand sanitizer on it, and it went away within days.
I do notice that the blisters seem to improve while washing dishes.
I think the green soap and the hand sanitizer may well be the best way to treat it.
Would be open to comments on how this works for you all.
July 14th, 2010 at 8:55 pm
I was bitten by one of these in San Diego(East County) The first one popped and developed more little ones around it. They are not painful, just gross looking. I read that they live off wild flowers and in alfalfa. Perhaps they are coming in on surrounding properties horse ranch? I also read that they are attracted to light. I hope this helps. They are extremely toxic if ingested.
July 12th, 2010 at 10:26 pm
anyone out there know how to treat one of those blisters? my two year old boy has something that sounds very similar to the blisters described on this forum. I would really appreciate the help.
July 8th, 2010 at 9:40 pm
I was picking Tomatoes in my Grandfathers friends garden and i saw a ton of blister bugs. I tried not to touch them but I was wearing flip flops and I guess 1 touched my toe and 2 days later a blister appeared. Its been 8 days since ive had the blister I havent messed with it hoping it will go away but now that I know that I should NOT pop it, I feel much better.
THANK YOU!!!
*BTW* Im 11 years old and I live in Central Texas*
June 11th, 2010 at 3:36 pm
Great Site! It answered all my questions – am using triple antibiotic ointment and now I won’t pop anymore of the blisters! I thought that all of the blisters were from individual bites – creepy!
June 5th, 2010 at 10:01 pm
ok ,I used to live out in the middle of no-where texas these critters are severe down there two or threetimes a month I would wind up getting one or twenty blisters and the trick o healing them is before popping the blisters ,put a layer of vaseline around the base of the blister then puncture only in one location and do not allow liquid to flow beyond the vaseline by gently tapping or dabbng with a dry double folded napkin then trash the napkin .the small needle hole helps wound heal much more rapidly
June 2nd, 2010 at 6:03 pm
HI, we think we may be getting reactions from some species of blister beetle. We feel and see the red dime-sized reaction sites after we have come inside from weeding the garden. My first “bite” was the third week of April this year (2010)…and I still have it! The blister part and the redness have decreased into a blister center with appears to be drying up. Seven weeks…and the first bite is still there! If I tough the area (clothes rubbing or scratching) the itching and pain flare up again. We live in Fallbrook, CA and do not really know what kind of “bites” these are, but my dermatologist says they are NOT BED BUGS nor fleas or mosquitoes. She does not think they are spider bites either. We have gone over every inch of our house, bedding and clothing looking for insects. If what you say is true, and I think it must be, then if we had one blister beetle on or inside our clothing, scratched if off or even knocked it off…the “blistering agent” still remains on our clothing, etc. This would explain the delay in reactions.
We know that our neighbors are suffering from these same kinds of insect “bites”. What can we do? How did southern california get these bugs? Our town is a costal agricultural center.
May 8th, 2010 at 2:22 pm
I’m back to report: Apparently, blister beetle encounters are also able to elicit post-traumatic stress bordering on paranoid psychosis.*** I say this because ever since my attack 2 months ago, any flying object heading my direction causes me to wildly duck, wave my arms, sometimes even scream and run away. Heaven help me in the times I don’t see it coming, but instead feel it land somewhere on my body or in my hair. The flying creatures are winning this year, already forcing me to seek refuge inside versus completing the ever-present chores of summer yardwork. And jus when I thought it was safe to go inside, I hear something buzzing in an adjacent corner of my den…
So, it’s official. Blister beetles cause PTSD. LOL
***tongue-in-cheek and meaning no disrespect to actual survivors with post-traumatic stress disorder
May 7th, 2010 at 7:06 pm
shani
In my experience, the initial blisters kept spreading in size for a week, but didn’t spread to other sites–unless one breaks, and then where ever that fluid touches, you can get a new one, which also keeps enlarging. Do not pop them, no matter what! I think mine quit increasing in size after a week, but it was two full weeks before they shrank up and were gone. If you have them all over, i don’t know what to say. I don’t know if an emergency room visit is needed. But if you go, don’t let them pop them either!
May 6th, 2010 at 11:05 pm
I was bitten by this nasty creature blister beetle 5 days ago and i am still suffering with a pain.It spreads like nothing all over the body.I’m very worried thinking how long will this blisters take to heal???and what should i do to prevent these blisters spreading??
March 22nd, 2010 at 6:18 am
I’ve been raking up the alley behind my house. I turned up with a big, fat blister on my arm which looked very much like a cigarrette had been put out there. However, I can’t recall being burned at all! I’m pretty sure it’s got to be due to one of these bugs. I did pop the blister because it looked so bad. Now it is a crater with a pink raised edge. So, it still looks bad but it is more itchy than painful…another reason I’m pretty sure it is no burn. I’ll definitely avoid the bugs I see that look like this in the future! Thanks for the info, and for the record I live in Fort Worth, Texas…
March 19th, 2010 at 7:12 pm
To Kathy: I don’t know how that could possibly have worked–but even if it did, I’m thinking maybe I’d rather just die than have those blisters hurting with each breath I took, for a week or more lol
March 18th, 2010 at 10:08 pm
My great-grandpa told of having a “lung ailment” that nearly killed him. Fortunately there was a swarm of blister bugs nearby so the doctor (this was late 1800′s, in Texas) made a poltice of the bugs and mashed it on his chest. He claimed the blisters “drew out the poison in his lungs” and his life was saved. Pretty drastic treatment, if you ask me.
January 23rd, 2010 at 9:28 am
Hellish bugs, but they do have some odd weaknesses, in my experience. For example, they hate noise. Banging on a piepan or loud rock music nearby will make them move, as will repeatedly shaking the leaves of the plants with a small tree branch or such. But don’t touch ‘em. And don’t mow or weedeat near them, as the blistering agent can end up anywhere. My two cents from the Missouri Ozarks.
January 3rd, 2010 at 7:44 pm
Ive been to doing pest control for years in London always good to find great information
November 28th, 2009 at 1:14 pm
I got these a couple times when I was young, so did a couple of my siblings. As I recall: VERY painful blisters, which would enlarge over the first few days. But DO NOT pop them! No matter how careful you are, you will get a little of the fluid on another area of skin, and then that area gets the same symptoms (blisters enlarging over a few days). I remember the symptoms being gone in less than a week when I was about 10, but it took almost 2 weeks when I was 18. Maybe a different species of the bug, or the difference in age, who knows? Now, I think I’d be asking my doctor for strong lidocaine patches or gel, if available. Those blisters were many times more painful than any other blister I’ve ever had.
September 23rd, 2009 at 6:40 pm
So this is what’s getting my tomatoes! And it’s what left a blister on me just under my right eye today! Just thankful it didn’t happen inside my eye–didn’t miss it by much! Scared to go back out and check the tomatoes again. And to let my cats out!
September 19th, 2009 at 2:49 am
To laura. regular medical doctors never know the problem when it comes to skin like problems. go see a dermatologist (skin doctor).
September 6th, 2009 at 9:16 pm
Jennifer
I am not a doctor but if is the case then get them straight to the hospital
September 6th, 2009 at 8:02 pm
My son turned up with this awful blister on the side of his foot which just got bigger and bigger. The pediatrician thought it was a staph infection so he popped it to get a culture. My son then got three more huge blisters on the bottom of his foot. I learned about beetle blisters and was told to pop the new ones, but don’t touch the liquid. I popped the blisters (and wore gloves), but my 11 year old touched the liquid. He now has bumps forming on both hands and some new places on his foot. Could these blisters really be from the liquid inside his first bite? I will take him to a dermatologist this week. And, if we can just leave the blisters alone and not pop them, will they really dry up?
September 2nd, 2009 at 7:00 pm
I need help treating myself. I have blusters all over and they are now really red and look infected. I have been to 3 doctors and no one can help me . They haven’t heard of these beetles. Please help me . I am having a severe allergic reaction!
August 16th, 2009 at 10:01 am
Thanks for the info! I just found these buggers eating their way through my hostas! I hand picked as many as I could & will keep an eye for more. And of course wear gloves when I handle them.
August 2nd, 2009 at 7:12 pm
Great info. Found them on my tomato plants in Williamsburg, VA. They drop when bothered so I used a tin can to catch them. Then I terminated them with rubbing alcohol. Good to know about their toxicity. I did not crush them but I did touch them so I might be in for some blisters. Thanks.
April 9th, 2009 at 11:52 pm
Thank you for the information. I have looked up several websites about these blister beetles, none of which gave me any methods of getting rid of them.
October 30th, 2008 at 12:38 pm
wow, great site for information, i been doing pest control in england for years and i have never heard about some of these pests your talking about, its great
August 18th, 2008 at 12:27 pm
I thought this article was mainly about the destructive nature of the blister beetle and not neccissarily about the effects of the toxins on the skin. I would like to know more about organic methods of controling or wiping out this particular garden monster as they are eating our eggplant plants and it is very labor intensive to hand pick.
July 6th, 2008 at 9:46 am
I’d take him to the doctor. It sounds like it’s infected and should be treated. Some people have allergic reactions to bites like this.
July 6th, 2008 at 12:14 am
July 5, 2008 – North Texas
My son has a long blister on his right shoulder, about 3-4″, which looks like a bug has crawled accross his skin, cutting through the skin and leaving a trail of blister-looking material. The first day it was fat like a bubble blister, but long. It has gradually started drying up, but today is day three and it still has small blisters. We have doctored it with 2% anti-itch hydrochloride, and he has tried not to bother it.
He found a dead bug in another room which resembles the bugs in the pictures.
Please respond if there is anything else we can do.
August 20th, 2007 at 9:30 am
Blister beetles are nasty! They get into my horses hay and then my poor babies get huge nasty ulcer-like blisters on the insides of their mouth. It takes weeks to heal because a horse can keep their mouth very clean. I’ve had two get them so far (in one year). It nice to have a place to get info about them, though…great site!
-Kim
Southern California
June 19th, 2007 at 10:08 am
I used to live in south Texas. This bug would get on me. It would leave a bister
on me. If I open the bister it takes a week or so to get well. If you leave
it alone it would go a way in two to three days. Corky