Insect-induced Plant Galls of California
September 18, 2011
Kathy Schick, Joyce Gross, and Diane M. Erwin
UC Berkeley
Co-sponsored by the Essig Museum of Entomology and the University of California Museum of Paleontology

Plant galls provide a fascinating array of color and texture on most of the plants in our California landscape. Galls, growths of plant cells that are not normal plant organs, can be induced by a number of organisms. The most numerous as well as most beautiful and intriguing are those induced by insects. Two insect families are found only in plant galls: Cynipidae (gall wasps) and Cecidomyiidae (gall midges or gnats). Plant galls also host a whole ecology of other insects, including herbivorous inquilines and carnivorous parasitoids like the wasp family Ormyridae, which is found only in plant galls. Most of these organisms are too small for us to see, so that the only thing we notice is the colorful gall growth itself.

In this workshop, we will start by exploring the diversity of extant insect-induced plant galls and some of the community of species to be found within them. We will begin our study indoors, using some of Joyce Gross’s excellent photographic images of galls and gall insects. Then, we will take a short campus field trip to learn how to find galls; many do occur on plants common in California gardens. We will then dissect and examine galls under microscopes to tease out the development and origins of the gall tissue layers. We will wrap up with discussion about the evolution of the plant host-plant galler interrelationships with examples from fossil galls.

Course fee $115/$140

Registration information here