Insect Identification logo

Iron Cross Blister Beetle (Tegrodera aloga)

Detailing the identifying qualities of the Iron Cross Blister Beetle, including physical features and territorial reach.

 Updated: 8/29/2017; Authored By Staff Writer; Content ¬©

  Iron Cross Blister Beetle  
Picture of Iron-Cross-Blister-Beetle

Native to the Sonoran desert, the Iron Cross Blister Beetle is dangerous to touch and poisonous to eat, making it hazardous to people, pets and livestock.

The bright yellow network covering black elytra are warning colors themselves. Add the red head to the overall appearance of the Iron Cross Blister Beetle and it becomes a bonafide alarm. A parting of the yellow at the midline and in the center of the elytra form a black cross. This species eats native wildflowers and herbs as well as the leaves of crop plants like alfalfa, potatoes, beans, and clover. This agricultural diet increases the likelihood of a human encounter in the field. Adults are active in the day, and sometimes at night, and it is usually seen meandering on the ground or feeding on a plant, many times with others.

A toxic chemical called cantharidin is secreted from the legs and antennae of an Iron Cross Beetle when handled or touched, which causes painful blisters on human skin as well as on animals. If eaten in enough quantities, it can kill. While most people would refrain from eating beetles, this insect is sometimes unwittingly consumed by horses and livestock feeding on the plants where the beetle is present, causing death. Pets may also try to eat them. This same chemical has been used medicinally to kill and remove warts, so it helpful to people, too.

If seen, avoid contact with the Iron Cross Beetle and keep a wary eye for others that may be nearby.

Iron Cross Blister Beetle Information

Category: Beetle
Common Name: Iron Cross Blister Beetle
Scientific Name: Tegrodera aloga

Taxonomy Hierarchy

 Arrow graphic Kingdom: Animalia
  Arrow graphic Phylum: Arthropoda
   Arrow graphic Class: Insecta
    Arrow graphic Order: Coleoptera
     Arrow graphic Family: Meloidae
      Arrow graphic Genus: Tegrodera
       Arrow graphic Species: aloga

Size, Identifying Tags and Territorial Reach

Size (Adult, Length): Size (Adult, Length): 14 mm to 26 mm (0.546 inches to 1.014 inches)
Identifying Colors: black, orange, yellow, red
Additional Descriptors: nerves, veins, lace, wings, head, blister, pain, dangerous, poisonous, harmful, flying

North American Territorial Reach (Though Not Limited To): Arizona; California; Mexico

A Note About Territorial Reach: Keep in mind that an insect's reach is not limited by lines drawn on a map and therefore species may appear in areas, regions and/or states beyond those listed above. Insects are driven by environmental factors, food supplies and mating patterns and do not nescessarily work within hard-and-fast territorial lines like we humans do.

BugFinder: What is it?