Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
Clickable Guide
Moths Butterflies Flies Caterpillars Flies Dragonflies Flies Mantids Cockroaches Bees and Wasps Walkingsticks Earwigs Ants Termites Hoppers and Kin Hoppers and Kin Beetles True Bugs Fleas Grasshoppers and Kin Ticks Spiders Scorpions Centipedes Millipedes

Calendar
Upcoming Events

Discussion, insects and people from the 2018 BugGuide Gathering in Virginia, July 27-29

Photos of insects and people from the 2015 gathering in Wisconsin, July 10-12

Photos of insects and people from the 2014 gathering in Virginia, June 4-7.

Photos of insects and people from the 2013 gathering in Arizona, July 25-28

Photos of insects and people from the 2012 gathering in Alabama

Photos of insects and people from the 2011 gathering in Iowa

Photos from the 2010 Workshop in Grinnell, Iowa

Photos from the 2009 gathering in Washington

TaxonomyBrowse
Info
ImagesLinksBooksData

Species Prionus californicus - California Root Borer

Large reddish brown beetle - Prionus californicus - female Prionus californicus Prionus californicus Motschulsky - Prionus californicus - male Prionus californicus - California Wood Borer - Prionus californicus California Root Borer - Prionus californicus Prionus californicus? - Prionus californicus - male Cerambycid - Prionus californicus Arizona Cerambycid - Prionus californicus
Classification
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Coleoptera (Beetles)
Suborder Polyphaga (Water, Rove, Scarab, Long-horned, Leaf and Snout Beetles)
No Taxon (Series Cucujiformia)
Superfamily Chrysomeloidea (Long-horned and Leaf Beetles)
Family Cerambycidae (Long-horned Beetles)
Subfamily Prioninae
Tribe Prionini
Genus Prionus
No Taxon (subgenus Prionus)
Species californicus (California Root Borer)
Other Common Names
The root-feeding larvae are sometimes called the "Giant Root Borer"(1)
Synonyms and other taxonomic changes
Prionus californicus Motschulsky 1845
Size
24-55 mm (1)
Identification
The following is from Evans & Hogue (1)

Adults:
Robust, reddish-brown to almost black;
Three sharp spines on each side of pronotum;
Saw-toothed antennae with 12 segments (scape, pedicel, and 10 flagellomeres...pedicel very short, 1st flagellomere longest, then decreasing in size apically)(1)

Males with antennae distinctly sawlike, more than 2/3 length of body.
Females with more slender antennae, about 1/2 length of body.

Larvae: Up to 80mm long
Range
w. N. Amer.
Season
Adults active summer through early fall; fly at dusk or in the evening.(1)
Food
Larva feed primarily on living deciduous trees (oaks, madrone, cottonwood) and are also recorded from roots of vines, grasses, and decomposing hardwoods and conifers. Will also attack fruit trees growing on light, well-drained soils (e.g. apple, cherry, peach).(1)
Life Cycle
Entire life cycle may require 3 to 5 years.(1)
Internet References
Works Cited
1.Field Guide to Beetles of California
Arthur V. Evans and James N. Hogue. 2006. University of California Press.