Euura sp.

Host: Salix fragilis

The specific identity of the species of Euura in this study is uncertain.

This particular species of Euura produces stem galls on crack willow, S. fragilis L. Apparently, this species of willow was originally planted from nursery stock and has become established along drainages in the Front Range of Colorado (Harrington, 1954).

Gall development occurred rapidly. By the end of May gall diameter reached 7.1 mm (Fig. 1). However, average gall size varied greatly throughout the season, ranging from a diameter of 5.8 mm (wet weight 0.22 g) to 10.5 mm (wet weight 3.3 g) (Fig. 2).

Range: East Plum Creek, near Castle Rock CO