This parasitic fungus with two alternating hosts, at different stages of its life cycle, is a major agricultural pest. Galls on stems of Eastern Redcedar trees produce jelly-like orange horns that bear spores. These spores infect apple leaves. In turn, the small dense yellow spore case clusters on apple leaves disseminate spores that produce the galls found on cedars (J. Solem, pers. comm.).
In addition to apple, certain other members of the Rose Family (Rosaceae) may also be infected by Cedar Apple Rust, including crabapple, hawthorn (Crataegus species), and serviceberry (Amelanchier species). These plants suffer more damage from the fungi than do the cedars, which are relatively resistant.
Cedar Apple Rust fungi overwinter on cedar trees as hard, dull-brown galls. The galls put out the gelatinous "horns" in response to spring rains, and the spores released are carried by wind or insects to the alternate host trees. During dry spells, the horns of the galls on the cedar shrivel, to reawaken with new rain.
There are 192 records in the project database.
| GA | AL | WA | FR | CL | MO | HO | BA | BC | HA | CE | PG | AA | CV | CH | SM | KE | QA | CN | TA | DO | WI | SO | WO |
