Eriophyes calaceris

Hosts: Acer glabrum

This is a colorful and impressive erineum on maple leaves caused by Eriophyes calaceris in the Western United States. The erineum growth is pustulelike, consisting of a brightly colored aggregation of tiny papillae. Each papilla is filled with colored fluid, and when magnified it has a rounded or capitate tip. The erineum appears on the upper surface of the leaf and is thickest from the apical half to the edge of the blade, missing the larger veins. It ranges from greenish yellow to pink, crimson, and purplish red. The infestation may be wide-spread on some trees.

The life history involves alternation of generations. The mites continue to colonize the erineum until September and then migrate to stems or twigs and bark crevices. Deutogynes overwinter in bark crevices and then move to newly developing buds in the spring. The inquiline eriophyids Aculops glabri (Keifer) and A. paraglabri (Keifer) are frequently in the erineum. Aculops paraglabri was recently found to be the overwintering form (deutogyne) of A. glabri and is therefore a synonym.

This mite was found abundant on Rocky Mountain maple in September in California. It is probably generally distributed throughout the range of the host plant from Alaska to California and east to South Dakota and New Mexico. Eriophyes calaceris may be confused with E. elongatus Hodgkiss, which commonly infests sugar maple (Acer saccharum Marsh.) in the Eastern United States. In addition to the differences in morphological structures, the erineum growths caused by each species are distinguished by their position, form, color, and density.

- Hartford Keifer,Edward Baker,Tokuwo Kono,Mercedes Delfinado,William Styer: (1982) An Illustrated Guide to Plant Abnormalities Caused by Eriophyid Mites in North America^©