2013: Blue Oak
with an Enormous Load of Galls
In early September, 2013, in Del Puerto Canyon, west of Patterson, CA,
some friends and I stumbled on the biggest population of Andricus crystallinus
galls I've ever seen. The blue oaks (Quercus douglasii) were so loaded with galls that
the trees appeared a dark pinkish red color from a distance even though the leaves are bluish green (and do not change color even when they
drop in the fall).
While Andricus crystallinus was the most numerous gall, there were also many other galls, including those made by
Andricus gigas, Antron quercusechinus (= Cynips quercusechinus), Andricus atrimentus, Disholcaspis canescens,
Liodora pattersonae (= Andricus pattersonae), and Besbicus multipunctatus (= Cynips multipunctatus).
It seems 2013 has been a banner year for A. crystallinus. I've seen higher-than-usual numbers of
their galls in other locations with blue oaks. However, none of those other locations have had numbers as high as the
trees in Del Puerto Canyon, and in a few locations it was actually hard to find any of these galls. It will be interesting to
see how many A. crystallinus galls are on
the Del Puerto Canyon trees next year.