Meloidae

Common name

Blister beetles

Overview

Blister beetles, family Meloidae, are a group of beetles known for their ability to secrete a blistering agent called cantharidin. This family includes approximately 7,500 species worldwide.

Taxonomy

• Kingdom: Animalia
• Phylum: Arthropoda
• Class: Insecta
• Order: Coleoptera
• Family: Meloidae

Key Characteristics

• Size: Typically range from 1 to 2.5 cm in length.
• Coloration: Often brightly colored or iridescent; can be black, blue, green, or yellow.
• Body Shape: Soft-bodied with a pronounced neck between the head and thorax.
• Antennae: Filiform (thread-like) and relatively long.

Life Cycle

• Egg: Laid in clusters on or near host plants or in the soil.
• Larvae: Known as triungulins in their first instar, often parasitic on bee or grasshopper eggs.
• Pupation: Occurs after several larval stages.
• Adult: Emerges from pupa ready to reproduce.

Behavior and Ecology

• Habitat: Found in a variety of environments, from deserts to forests.
• Diet: Larvae are parasitic, adults feed on plant material, including flowers and foliage.
• Defense Mechanism: Secretes cantharidin, causing severe blistering upon contact with human skin.

Notable Species

• Epicauta vittata: Striped blister beetle.
• Lytta vesicatoria: Spanish fly.
• Meloe proscarabaeus: European oil beetle.

Conservation

Blister beetles are not currently listed as endangered, but habitat destruction and environmental changes could impact certain species.

Significance to Humans

• Medical Use: Cantharidin is used in medicine to remove warts.
• Agricultural Impact: Some species are pests to crops like alfalfa and potatoes.

Fun Facts

• Blister beetles are named for their ability to create blisters on human skin.
• The Spanish fly (Lytta vesicatoria) is famous, or rather infamous, for its use as an aphrodisiac, though it is highly toxic.
• Larvae of blister beetles undergo hypermetamorphosis, a process involving multiple distinct larval stages.
• Cantharidin, the toxic substance in their secretion, was used as an ingredient in ancient aphrodisiacs and love potions.
• Blister beetles exhibit a phenomenon known as "reflex bleeding," where they secrete cantharidin-laden blood from their leg joints when threatened.