Phytocecidia
Guides
Euura californica
Willow Apple Gall Sawfly
Euura californica, the willow apple gall sawfly, is a tenthredinid sawfly that induces distinctive galls on arroyo willow (Salix lasiolepis). Females oviposit into leaf tissue, triggering the formation of rounded, apple-like galls that enclose developing larvae. The species exhibits multivoltine breeding with up to six generations annually in favorable climates. Adults emerge through exit holes chewed in mature galls.