Other Common Names
Valley Elderberry Longhorn Beetle - VELB
Explanation of Names
'dimorphus' - refers to differences in appearance between the males and females.
one ssp., D. c. dimorphus - currently listed as a federally threatened species, but is not state listed.
The forewings of the male are primarily red with dark green spots, whereas those of the female are dark metallic green with red margins.
females of the subspecies are basically indistinguishable without DNA or locality data (per Phil Schapker, 2013)
D. c. dimorphus is restricted to California's Central Valley
In CA's Central Valley, the elderberry tree is associated with riparian forests which occur along rivers and streams.
Historically the beetle ranged throughout the Valley, but recent surveys have revealed the beetle to persist only in scattered localities along the Sacramento, American, San Joaquin, Kings, Kaweah, and Tule rivers and their tributaries. Over 90% of CA's riparian forests have been cleared in the past century for agricultural, urban, and suburban development.
asso. w/ elderberry trees (Sambucus spp.) during its entire life cycle.
The adults emerge in the spring from pupation inside the wood of these trees as they begin to bloom. The exit holes made by the emerging adults are distinctive, small oval openings. Often these holes are the only clue that the beetles occur in an area. The adults eat the elderberry foliage until about June when they mate. The females lay their eggs in crevices in the bark. Upon hatching, the larvae then begin to tunnel into the tree where they will spend 1-2 years eating the interior wood, their sole source of food.
Current efforts to save the Valley Elderberry Longhorn Beetle (VELB) have focused on revegetating riparian habitats. The California Department of Water Resources has assisted the U.S. Fish and Wildlife Service in replanting elderberry along parts of the American River. Efforts are currently underway to reintroduce the beetle itself into areas which it formerly inhabited. Some success has been achieved by transplanting inhabited trees to a site near Sacramento.
Barr, C.B. 1991. The distribution, habitat, and status of the Valley Elderberry Longhorn Beetle Desmocerus californicus dimorphus Fisher (Coleoptera: Cerambycidae). U.S. Fish and Wildlife Service. Sacramento, CA.
Eng, L.L. 1984. Rare, threatened and endangered invertebrates in California riparian systems. In: R.E. Warner and K.M. Hendrix. (eds.) California riparian systems Ecology, conservation, and productive management. University of California Press, Berkeley.
VELB Species Page
- Essig Museum, UC, Berkeley
Desmocerus c. dimorphus
- Cerambycidae Catalog