Ever seen a blister beetle? Blister beetles are a common problem in fields and gardens. When hurt or crushed, they release a substance that makes welts. Cantharidin is a blistering agent found in secretion. It is used to treat the sores caused by the pox virus. Cantharidin is so good at killing tissue that it is used in products to get rid of warts.
If you swallow cantharidin, it will hurt you. It stays in dead beetles long after you dry the beetles. Horses are especially likely to get sick from the poison. Depending on the type of beetle, as few as four to six grams of dead insects can kill.
If a person eats the blister bug, it will hurt their urinary tract and the lining of their stomach. If there are blister beetles around, keep an eye on kids who put things in their mouths. Are blister beetles dangerous? The beetle is dangerous because it is poisonous and also hurts garden and commercial plants by eating a wide range of leaf crops, plant blossoms, landscape flowers, and hay crops.
Understanding Blister Beetles?
So, what are blister beetles? Or you may ask, what is a blister beetle? Blister beetles (Coleoptera: Meloidae) get their name from the cantharidin toxin that is found in their body fluids. This toxin can cause blisters on human skin and inflammations in horses and other animals that can be life-threatening.
Cantharidin is also found in the well-known aphrodisiac Spanish fly. Field crops like canola, dry beans, alfalfa, sweet clover, soybeans, and potatoes can have problems with blister beetles.
They eat the flowers and leaves of a wide range of plants, such as those in the Amaranthaceae, Asteraceae, Fabaceae, and Solanaceae families. When they gather in large numbers on a plant, they can cause a lot of damage to the leaves of that plant.
Blister beetles like to hang out together and can be found in large groups in certain parts of the field. Blister beetles aren’t usually very bad pests, and they only cause damage to crops when certain conditions are met.
But when they show up in alfalfa and other crops that horses and other animals eat, they can make them very sick or even kill them.
How to Identify Blister Beetles?
To protect livestock and prevent crop damage, it is important to be able to tell blister beetles apart from other types of non-toxic beetles that may look like them, such as the asparagus beetle. Blister beetles in the family Meloidae live all over the U.S. There are about 250 different kinds of blister beetles.
There are many different kinds of beetles in the east, south, and midwest. They can also be found in the west and southwest grasslands and gardens along the Pacific coast. The size and color of adult blister beetles can vary. Most are between half an inch and an inch long and have long, soft bodies, wide heads, and antennae that are a third as long as their bodies.
The area between the head and the body is called the prothorax. It is narrow and looks like a neck. The covers of the wings are soft and bendy, and the legs are pretty long. Moreover, colors can be bright and different, or they can be flat or striped. Striped blister beetles are different shades of grey and brown, and their wing covers have yellow stripes that run from end to end. The whole ash-gray blister beetle is grey.
The black blister beetle is black all the way through. The margined blister beetle is black, and each of its wing covers has a band that goes from grey to cream.
Blister Beetle Facts!
- The blister beetle’s larva is sometimes called a parasitoid because it feeds on a living host until it has enough energy to move on to the next stage of its life cycle. But unlike a real parasite, this always causes the host to die. After hatching, the larva can move around a lot, which helps it find a suitable host. As it grows up and settles down, it moves around less, but as an adult, it moves around a lot again so it can move between flowers.
- Cantharidin, a poison that this beetle produces has been used historically as an ointment (for gout or arthritis), an aphrodisiac, and a treatment for warts in a variety of cultures. Furthermore, some people call this treatment “Spanish fly” because the toxin comes from a similar species.
- The male of many beetle species, including the Arizona red-headed blister beetle, will link to it’s mate for more than 24 hours to reproduce. As she carries him around, the female keeps going from flower to flower to eat.
- After mating, the female beetle will bury maybe hundreds of eggs in the ground and let them hatch on their own. Moreover, she doesn’t care for the eggs, but she might coat them with a bit of her own poison to make them even safer. The blister beetle has a complex life cycle once it comes out of its egg. During the winter, it goes through several larval stages, sometimes as many as six or seven. They change into a pupa in the spring, and they come out as adults in early summer. Most species only have one generation each year.
Blister beetle Diet:
The blister beetle usually eats everything. It eats both insects and plants over the course of its life. Many different kinds of mammals, birds, reptiles, and frogs eat the blister beetle. But the painful toxin is a strong deterrent for any would-be predator that hasn’t gotten used to it.
During its life cycle, the blister beetle changes what it eats. As a larva, the beetle eats grasshopper or bee eggs. It sometimes follows an adult back to its nest. Moreover, the beetle eats plant leaves, flowers, and nectar as an adult. Most of the time, they go after ornamental and vegetable crops.
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Blister beetle Life Cycle
Adults start to lay clusters of eggs in the middle to end of spring and keep doing so for most of the season. A female will lay anywhere from one hundred to two hundred eggs that are less than a millimeter wide and one to two millimeters long just below the surface of the soil. In a little under two weeks, the eggs will hatch.
The white larvae that come out of the egg pods have long legs that they use to look for grasshopper egg pods to eat. Others live on bees and are called “bee lice” because they stick to them. As they go through the next stages of development, from larva to legless grub, they eat the eggs and food in the bee nest.
After almost ten days, when the pupal stage is over, the adult falls to the ground and starts eating plants that have been grown. Adults will go to flowers to eat nectar, pollen, and sometimes even the whole flower. Some blister beetle species will even eat leaves.
When the larvae change into pupae in the fall, they can spend the winter just below the soil. Most of the time, they can live up to three months. During their lives, females can make more than one cluster of eggs.
Are Blister Beetles a Threat to Livestock?
The most dangerous thing blister beetles do is cause a condition called cantharidin toxicosis in livestock. Alfalfa hay with a lot of blister beetles and toxic amounts of cantharidin can be very bad for the health of horses, cattle, and sheep, especially if they eat a lot of it.
Cantharidin, however, is a fairly stable chemical that remains harmful to animals. This is when the dry remains of beetles that die during harvest are fed as feed. You can sell or feed alfalfa and other types of hay if they infest crops.
Growers of hay and feed crops should do everything they can to keep an eye out for and stop infestations. As the beetles eat, they tend to group together. This makes it more likely that one or two hay bales will have a lot of the insects.
Also, when you buy hay, you should be careful. Find out if blister beetles are a problem in your area, and carefully check anything you buy.
Are Blister Beetles for Horses?
Poison from a beetle blister is especially dangerous for horses. A horse’s digestive tract can become inflamed, leading to other infections and bleeding. It’s interesting that you don’t have to eat the beetle to get sick. If they contaminate the hay with the body fluid, it can be just as harmful.
The chemical lowers the amount of calcium in the blood and irritates the lining of the stomach, small intestine, bladder, and tubes that carry urine. When horses eat cantharidin, they may show signs of colic, such as excessive salivation, diarrhea, bloody stools, sweating, dehydration, cramps, and frequent bathroom visits.
Veterinary attention is necessary immediately if blister bug poisoning is suspected; else, animals may pass away within 72 hours. A dose that kills leads to fever, depression, shock, and eventually death.
The severity of the reaction depends on how much cantharidin the animal ate, how big it was, and how healthy it was. It can range from temporary poisoning to a digestive system that doesn’t work as well as to death.
The amount of cantharidin in different kinds of beetles varies. There may be up to 50 times more cantharidin in some species than in others. Cantharidin affects different horses in different ways.
Even though it hasn’t been proven for sure that cantharidin is dangerous to horses, the estimated lethal dose is between 0.5 and 1 milligram of cantharidin per 2.2 lbs of horse body weight.
Are Blister Beetles Dangerous for Crops?
Blister beetles will eat pretty much every leaf in your garden. You can find them on tomato, potato, eggplant, pepper, and other nightshade plants, as well as on leafy greens. In the middle and end of summer, they can come in large groups that seem to appear out of nowhere. Because of how many there are, they can do a lot of damage in a short amount of time.
Blister beetles can also hurt grasshoppers, which are one of the worst pests for farms and gardens. Common blister beatle larvae that just hatched use their legs to look for groups of grasshopper eggs to eat. In this way, blisterbug can be seen as good bugs, but only when they are larvae. When they grow up, they only cause trouble.
How Do You Identify The Blister Beetle?
There are so many different colors and shapes of blister beetles that it may be hard to tell them apart. The easiest ways are to look for a small neck or thorax, a narrow abdomen, and a body that isn’t too hard. Some of them also have bright colors on their bodies.
How To Get Rid Of Blister Beetles?
Pesticides are a good way to control the number of blister beetles. If that isn’t an issue, it’s a good idea to work around the beetles’ behavior. Gather your crops before they get there.
Where Are Blister Beetles Found?
The blister beetle is a widespread insect that thrives in tropical and subtropical regions. They usually hang out near flowering plants.
Do Blister Beetle Bites Humans?
Most of the time, blister beetles don’t bite people. Instead, they send out a painful poison that can cause dermatitis when they feel threatened. The blister beetle bites themselves aren’t too bad.
How Many Legs Do The Blister Beetles Have?
The blister beetle has six legs, just like every other insect.
What Does A Blister Beetle Look Like?
The blister beetle has a medium and soft body with a wide head, a narrow thorax, and a long, cylindrical, or bulbous abdomen. Aside from that, they come in many sizes, colors, and shapes. Many of them have bright markings to warn predators that they are poisonous, but this is not always the case. Some species are mostly black or grey on the outside.
Parvaiz Yousuf is a senior SEO writer and editor with an experience of over 6 years, who also doubles up as a researcher. With an MSc zoology degree under his belt and possessing complete Search Engine Optimization (SEO) knowledge, he works as a science journalist for a US-based website and Asian Scientist (A Singapore-based magazine). He also works as Director of Wetland Research Centre, Wildlife Conservation Fund YPJK since 2018. Besides, he has several publications to his name on cancer biology and biochemistry in some reputed journals such as Nature & International Journal of Molecular Sciences, & magazines such as Science Reporter, BUCEROS BNHS, and has an abiding interest in ornithology. He also worked as a Research Associate for JK Policy Institute.