The Life Cycle for
Zoophthora (Erynia) radicans

A potato leafhopper infected with Zoophthora radicans (formerly Erynia radicans) may produce either resting spores or conidia. Generally, if a young leafhopper is infected, primary conidia are produced, while if an older individual is infected, resting spores are produced. Conidia produced by entomophthoralean fungi are not passively released as are the conidia of the Ascomycetes, but are forcefully discharged from the infected leafhopper. If one of these conidia encounters a susceptible host, a germ tube is formed, the fungus invades the hemocoel and the infection progresses. If the conidium discharged from the host lands on a substance other than a susceptible host, it may form a secondary conidium, which is also forcefully discharged. Some species of entomophthoraleans may also produce capilliconidia if the primary conidia land on certain substrates other than a susceptible host. The capilliconidia, born on a long stalk, adhere to insects walking along the substrate. They produce typical infections. Resting spores, produced inside the host, are released from infected insects when the insect dies. The function of resting spores is to withstand unfavorable environmental conditions. This usually means overwintering. In the spring, overwintering resting spores germinate, form infectious germ conidia and the cycle is repeated.