Green Blister Beetle: Essential Facts and Tips

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The green blister beetle is a fascinating insect belonging to the Coleoptera family Meloidae, known for its vibrant, colorful appearance.

These beetles are predators of bee and grasshopper egg masses in their larval stage and feed on flowers and sometimes leaves of various plant species as adults.

Nuttail’s Blister Beetle

These beetles come in other colors such as blue, grey, and spotted, but the green variety is particularly captivating due to its metallic sheen.

When comparing different species, the green blister beetle is similar to its relatives in size, ranging from 1/3 to 2/3 inches long.

However, all blister beetles share a distinct feature: a narrow “neck” that contrasts with the broader head and abdomen.

Green Blister Beetle: The Basics

Taxonomy and Classification

Green blister beetles belong to the family Meloidae and are a type of blister beetle commonly found across the United States and Canada.

These insects are known for their elongated, narrow, and soft bodies and typically belong to species such as the three-striped, grey, and black blister beetles1.

Physical Features: Colors, Sizes, and Body Shapes

Green blister beetles can exhibit various colors, including black, gray, and even metallic sheens like purplish-green in the case of Nuttall’s blister beetle2.

The body length of these beetles usually ranges from 0.5 to 1.25 inches3.

Some notable physical features of green blister beetles are:

  • A narrower visible part of the thorax than the head and abdomen3
  • Front wings that do not extend over the tip of the abdomen3
  • A distinctive narrow “neck” that contrasts with the broader head and abdomen4


The fluids within these beetles contain a chemical that can cause skin irritation if touched, hence the name “blister beetle”.

Life Cycle and Reproduction

Egg Stage

The life cycle of the green blister beetle starts with the egg stage. Female beetles lay their eggs in shallow soil cavities during the summer.

The eggs hatch after spending around 7 to 10 days1 in this stage.

Larval Stage

The next stage in the life cycle is the larval stage, which is mainly focused on feeding and growth.

The larva usually targets grasshopper eggs as their primary food source. In the case of the margined blister beetle, the larva is known to feed on legumes2. During this stage:

  • Larvae undergo several molts
  • They develop and grow for up to several weeks

Adult Stage

After completing the larval stage, the beetle undergoes pupation. The adult blister beetle emerges after about 2 weeks3.

The adult stage mainly consists of feeding, mating, and laying eggs. 

FeatureEgg StageLarval StageAdult Stage
Duration7 to 10 daysSeveral weeksVaries
Primary ActivityDevelopingFeeding on grasshopper eggs or legumesFeeding, mating, and laying eggs

Habitat and Distribution

Geographical Range

Green blister beetles are commonly found in North America, from Mexico to Canada.

They are also found in the United Kingdom, the West Indies, South and Central America, and northern Ghana.

These beetles favor warmer climates, so their distribution is more prevalent in the southern parts of these countries.

Blister Beetle: Lytta sayi

Where They Can Be Found?

Green blister beetles are typically found around:

  • Flowers: They feed on flower petals and nectar.
  • Crops: They can infest various crops, especially alfalfa and legumes.
  • Plants: They generally consume leaves, flowers, and soft plant tissue.

Alfalfa and Agriculture

In the agricultural sector, green blister beetles are particularly concerning for alfalfa production. They are attracted to this crop, especially during blooming.

The presence of beetles in alfalfa can cause problems for animals, such as horses and livestock, which may consume the toxic insects along with the plants.

Examples of places where you may find green blister beetles:

  • Gardens
  • Fields
  • Agriculture lands

Diet and Predation

What Green Blister Beetles Eat

Green blister beetles, also known as Epicauta species, primarily feed on plants. Some common targets include:

  • Flowers
  • Leaves
  • Alfalfa hay
  • Various vegetable crops

These insects can be pests to crops and, in certain situations, can be harmful to livestock and poultry.

Natural Predators

The green blister beetle has several natural predators that help control their population. These include:

While the predators help to reduce the number of green blister beetles, it is still necessary to implement pest control measures to protect crops and livestock from their harmful effects.

Blister Beetle

Effects on Livestock and Poultry:

Livestock such as cattle, sheep, and poultry can suffer severe damage to their urinary and gastrointestinal tracts if they ingest cantharidin, a toxic compound found in blister beetles.

This can occur if the beetles are crushed and mixed into alfalfa hay or other feed sources.

To keep the damage from green blister beetles in check, it is important to use integrated pest management practices and support their natural predators in the ecosystem.

Interesting Facts and Uses

Historical Uses

The green blister beetle is a part of the blister beetle family, which has some interesting historical uses.

One well-known member of this family is the Spanish fly, which was once used as an aphrodisiac due to its ability to release a chemical called cantharidin1.

However, high doses of cantharidin can be harmful and can lead to severe health issues2.

Surprising Discoveries

  • Blister beetles contain a toxin called cantharidin3.
  • This toxin can cause skin irritation and blisters, hence the name “blister beetle”4.
Spanish FlyGreen Blister Beetle
AphrodisiacNot aphrodisiac
Dangerous if taken too muchCan cause skin irritation


Green blister beetles, part of the Meloidae family, are captivating insects recognized for their vibrant colors and unique physical features.

Predatory in their larval stage, they target bee and grasshopper egg masses, transitioning to a diet of flowers and plant leaves as adults.

Their name derives from the skin-irritating chemical they contain, cantharidin. While they exhibit a range of colors, the metallic sheen of the green variety stands out.

Distributed mainly across the U.S. and Canada, these beetles play a significant role in the ecosystem, but their toxic nature demands caution.


  1. Dealing with Blister Beetles | UNL Beef 2 3 4 5

  2. Blister Beetle Management in Forages and Field Crops 2 3 4 5

  3. Blister beetles: Handle with care – MSU Extension 2 3 4 5 6 7 8

  4. Blister Beetle – Texas A&M University 2

Reader Emails

Over the years, our website, has received hundreds of letters and some interesting images asking us about green blister beetles. Scroll down to have a look at some of them.

Letter 1 – Green Blister Beetle

Blister Beetle
Location: Lashburn, Saskatchewan
August 6, 2011 11:33 pm
Found this beetle hiding in my camera bag, and I’m very curious to know what it is. It was about 1 inch long.
Signature: Chris

Green Blister Beetle

Dear Chris,
You are correct that this is a Blister Beetle, and we believe it is in the genus
Lytta, most likely either Lytta viridana or Lytta cyanipennis, the Green Blister Beetle

There is a section to BugGuide devoted to photos of what cannot be conclusively identified as either of these species, and it includes submissions from Saskatchewan and surrounding states in Canada and the U.S.


  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

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  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

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Tags: Blister Beetles

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