Zeuxidiplosis giardi
Hosts
St. Johnswort (Hypericum perforatum)

Description
Larvae are orange and can reach up to 2mm in length, completing three instars. Adults are very small (3 mm long) and have dark red bodies and gray heads, wings, and legs.

Life Cycle
Larvae emerge in early spring and feed on leaf buds, causing leaves to grow into a spherical gall that is green with reddish markings. Larvae feed at the base of the gall; pupation occurs inside. Adults are sexually mature upon emergence and live for only 5 days. There may be up to 7 generations per year, though there are usually fewer than 5. Larvae and pupae overwinter.

Impact
Larval feeding and galling lead to stunted plant growth and occasional death, though it is not as effective in the western U.S. as other agents.

Availability
Limited availability from California and Hawaii.

... Author: Rachel Winston, Mark Schwarzlander. University of Idaho Extension.

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Reference: https://wiki.bugwood.org/Zeuxidiplosis_giardi