Week Seventeen: Vegetable Caterpillar Fungus

Common Name: Vegetable Caterpillar, Caterpillar Fungus, Awheto (Maori)

Scientific Name: Cordyceps robertsii

Fun Fact: The indigenous people of New Zealand, the Maori, burned the fungus stalks for charcoal, which they used to draw decorative patterns on their skin. They also used it as a food source.

Domain: Eukaryota

Kingdom: Fungi

Phylum: Ascomycota

Class: Sordariomycetes

Order: Hypocreales

Family: Clavicipitaceae

Genus: Cordyceps

Species: C. robertsii

Description: Vegetable Caterpillar is a fungus that parasitizes the larvae of several species of moths. Vegetable Caterpillar encases the caterpillar in a cocoon that has been described as mummy-like. This so-called mummification slowly kills the insect larva as the fungus takes over its body, leaving it a hollow shell swathed in its predator. The fruiting body of the fungus is 2-3 mm in diameter and may be 20 cm tall.  To the casual observer, it may look like a small brown stem pushing up through leaf detritus.

Environment: This fungus is native to New Zealand and preys exclusively upon a variety of moth species also native to the islands. It infects its prey while the potential host is living on the soil as a larva. The host eats the almost imperceptibly small spores of the fungus and is therefore infected.

Reproduction & Development: After the host is infected, the fungus eats it from the inside out. Once the caterpillar is dead, the fungus sprouts a fruiting body from the neck of its host, which punches through any decaying plant matter on the ground to form a tall stalk. This fruiting body sprays new spores in all directions, allowing the cycle to begin again.

Nutrition: This fungus is a parasitic heterotroph, which means that it must eat a living host to survive. The nutrients the fungus steals from its host allow it to grow and produce reproductive spores.