The information in this leaflet includes details on the life cycle and habits of blister beetles and their importance to agriculture. Special attention is given to potential adverse effects of blister beetles on horses, signs and symptoms of poisoning, and suggestions for avoiding accidental poisoning. Introduction Insects in the family Meloidae are commonly referred to as blister or oil beetles. Different species vary in size and color, but most are easily recognized by their elongated, narrow, cylindrical, soft bodies. Viewed from above, blister beetles have an accentuated neck, caused by a constriction between the back of the head and the narrow anterior end of the thorax.
Blister beetles have a complex life cycle that is characterized by several immature forms.
Their life cycle is illustrated in the following description for Epicauta vittata, a three-striped blister beetle found in Kansas alfalfa fields. Striped blister beetles, as is true of most other common species, have only one generation per year. During the summer, egg clusters containing up to 100 eggs are deposited in the ground. Within two weeks the eggs hatch and the tiny larvae, called triungulin s, search for food, primarily grasshopper egg pods. Triungulins have legs designed for active movement.