The Palo Verde Beetle
I have always had an interest in entomology and honestly wished I had pursued it many years ago. I had taken the bug class at Solano Community College, we took a fieldtrip to the UC Davis campus to see there department and it was so fascinating! I was always able to understand and memorize all of the Latin names in horticulture, so this was just an extension of that. Kind of creepy and neat all at the same time. The other night I went out on my deck, I saw the largest beetle I have ever seen! I took some pictures and even got close enough to it to nudge it with the broom, but it just played dead. I sent my snapshot to Google and sure enough it is a Derobrachus hovorei or the Palo Verde beetle. It is native to the southwest and northern Mexico. They are in the Cerambycidae family, the long-horned beetle. When the male and females mate the females bore down about a foot to lay her eggs and when they hatch into grubs, they feed off of the trees for up to 3 years. They will feed on various trees and shrubs but most commonly the Palo Verde trees that grow in the Sonoran Desert, hence the name. The larvae can be up to 5” long, while the mature adult can get to 3 ½” long. They do not eat once they emerge, they survive on the stored nutrients, living for only about a month. There sole purpose is to mate and do it all over again. During Monsoon season there are hundreds of thousands that emerge in the summertime, flying about looking for a mate, after they mate, they die. They are a little scary looking but are harmless to people and so amazing!
After doing all this research, I then learned that it is in fact the Prionus californicus, California root borer. According to Karey Windbiel-Rojas, Associate Director for Urban and Community IPM, the main features to look for are the antennae. The California root borer has very distinct toothed antennae, whereas the Palo Verde beetle antennae are very segmented but not toothed. Either way this was a fun topic to research.
Palo Verde Beetle, Mandibles by cobalt123 is licensed under CC BY-NC-SA 2.0.
1943. California root borer. Prionus californicus. Adult male. by USDA Forest Service is marked with Public Domain Mark 1.0.