BOMBARDIER BEETLE (Stenaptinus insignis)

Pronounced:

Sten-ap-ti-nus in-sig-nis

Order:

Coleoptera

Kingdom:

Animalia

Family:

Carabidae

Phylum:

Arthropoda

Genus:

Stenaptinus

Class:

Insecta

Species:

Insignis

Like firefighters, there is a beetle that shoots liquid with such force, it knocks its enemies down. But unlike water, this liquid is burning hot and toxic! Bombardier Beetles are small ground beetles, about 1.2 to 1.8 cm long. They are nocturnal and carnivorous – eating mainly other arthropods. They scavenge alone, but congregate in groups when not actively feeding. Males have elongated mandibles which they use to fight other males for mates. They all have hard exoskeletons and wing covers.

About 40% of all known insects are beetles. Bombardier Beetles contain more than 500 species living in most parts of the world. The mechanisms and chemicals they use to spray differ amongst species. In African Bombardier Beetles, two chemicals are kept in different chambers along the beetle’s back sides. When needed, the beetle releases the two chemicals, which mix together and react, raising the temperature of the mixture to 100 degrees Celsius, and spraying it with force. The beetle has the incredible ability to swivel its spray apparatus in a radius of 270 degrees to reach almost every conceivable direction. A “pop and hiss” sound is heard when the beetle lets out its spray.

Why does it need this ability? As a ground beetle, its major predators are ants, as well as other ground-dwelling insects. Unlike other flying arthropods, a beetle’s wings are tucked into a protective case and take time to come out in order for it to take off. In those precious moments, a beetle could fall prey to an onslaught of ants or other predators. They have, therefore, evolved the ability to spray hot poisonous liquid at the ants, regardless of where they attack on the beetle’s body.

Bombardier Beetles lay a single egg at a time in cells made of mud that are then stuck to plants or rocks. The Larvae, or grubs, that hatch from the eggs, are carnivorous and often pupate within the tissue of the animal they parasitize. When they come out of their pupae, they are in adult form.