Aciurina ferruginea
Medusa-gall Tephritid

The galls are characterized by numerous long, thin leafy bracts, which appear to develop in fascicles.

...the gall of A. ferruginea is subspheroidal and covered by many thin, threadlike leaves, its shape apparently unlike other tephritid galls described to date.

...galls of both species were pictured by Wangberg (1981) from Idaho, so these two tephritids [A. michaeli and ferruginea] probably occur in sympatry throughout the range of C. viscidiflorus.

By this time, the galls already appeared very leafy and consisted of stunted axillary branches, which continued to produce leaves in fascicles from many tiny axillary buds as the galls grew (Fig. 8D).

Its inner surface is shallowly pitted and thinly coated with sap upon which the larvae principally feed, as described for A. thoracica by Headrick and Goeden (1993).