Galls on Ocotillo?
Location: Organ Pipe Cactus National Monument, AZ
February 28, 2011 9:39 pm
My field crew and I came across this ocotillo that has what appear to be galls on it. Are these deformities produced by an insect, and if so, which one? Thanks!
Signature: Ed Kuklinski
Dear Ed,
According to the Morton Arboretum website: “Galls are abnormal growths that occur on leaves, twigs, roots, or flowers of many plants. Most galls are caused by irritation and/or stimulation of plant cells due to feeding or egg-laying by insects such as aphids, midges, wasps, or mites. Some galls are the result of infections by bacteria, fungi, or nematodes and are difficult to tell apart from insect-caused galls. Seeing the insect or its eggs may help you tell an insect gall from a gall caused by other organisms.” What you have photographed does fall into the “abnormal growth” category, but we cannot say for certain that they were caused by insects. The desert is a harsh climate, and there might be many things other than insects that might have caused this unusual phenomenon. Perhaps one of our readers will provide some insight.
