A rare valley elderberry longhorn beetle (Desmocerus californicus dimorphus) perches on a leaf of its host plant, blue elderberry (Sambucus mexicana).

An adult male valley elderberry longhorn beetle (Desmocerus californicus dimorphus) perches on a leaf of its host plant, blue elderberry (Sambucus mexicana). Although classic metapopulations are thought to be uncommon in nature, this rare beetle displays characteristics of such a population dynamic: low local densities, discrete habitat patches, limited movements, and a strongly influenced of stochasticity. Found only within California’s Central Valley, the valley elderberry longhorn beetle was listed as threatened in 1980 under the U.S. Endangered Species Act, mainly due to loss of its riparian habitat. In 2007, it was proposed for delisting despite continued habitat loss, uncertainty about threats to its populations, and insufficient knowledge to accurately predict its occupancy patterns. This photograph originally appeared on the cover of Ecology (88:6) in June of 2007.