Delta green ground beetle
The Delta green ground beetle (Elaphrus viridis) is a species of ground beetle restricted to a small region within Solano County, California. Its color is a metallic-green, usually with bronze spots on its elytra, though some lack these spots. The lack or reduction of circular pits on the elytra helps distinguish it from other ground beetles. Typical adults are about a quarter-inch (0.6 cm) in length.
Range and distribution
The Delta green ground beetle is known to only occur in Solano County, though it may have historically occurred throughout the Central Valley. It is known to inhabit Jepson Prairie Preserve, south of Dixon, where it is protected; however, the beetle's other known ranges are located on public land.
The beetle occupies vernal pool habitats, around which its life cycle is based: it emerges in January following the filling of vernal pools from winter rains and lies dormant in May (around when the pools dry up) as a means of surviving the summer.
Specimens of the Delta green ground beetle have generally been collected in open habitats, namely the edges of vernal pools and nearby trails, roads and ditches. They may also be present in the surrounding grasslands, but the beetle's small size, camouflage against spring grass, and tendency to hide beneath low growth make it difficult to locate.
The Delta green ground beetle, in both its larval and adult stages, actively hunts soft-bodied arthropods. Based on the habits of other species of Elaphrus, it is likely that the beetle feeds primarily on springtails.
The Delta green ground beetle's current IUCN Red List status is Critically Endangered, owing to the species' extremely limited range and the endangerment of its vital vernal pool habitats. In addition, the species has been federally listed as threatened since 1980.
The destruction of vernal pool habitats in California is largely the result of agricultural development, though urbanization and grazing have played some role in their elimination. Another significant threat to the beetle is the introduced Garden lippia, which grows in dense mats in these habitats and impairs its ability to forage.
- "Delta Green Ground Beetle, Elaphrus viridis". Sacramento Fish & Wildlife Office. Retrieved on 14 August 2006.
- "California's Endangered Insects - Delta Green Ground Beetle". Essig Museum of Entomology - UC Berkeley. Retrieved on 14 August 2006.
- "Species Elaphrus viridis - Delta green ground beetle". BugGuide. Retrieved on 14 August 2006.
- World Conservation Monitoring Centre (1996). Elaphrus viridis. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on 14 August 2006. Database entry includes justification for why this species is listed as critically endangered.