Delta green ground beetle
Encyclopedia
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.
The beetle's common name probably refers to the triangular marking on its pronotum. The species name, viridis, comes from the Latin
word for green
.
, 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 grassland
s, but the beetle's small size, camouflage
against spring grass, and tendency to hide beneath low growth make it difficult to locate.
, it is likely that the beetle feeds primarily on springtail
s.
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.
Ground beetle
Ground beetles are a large, cosmopolitan family of beetles, Carabidae, with more than 40,000 species worldwide, approximately 2,000 of which are found in North America and 2,700 in Europe.-Description and ecology:...
restricted to a small region within Solano County, California
Solano County, California
Solano County is a county located in Bay-Delta region of the U.S. state of California, about halfway between San Francisco and Sacramento and is one of the nine San Francisco Bay Area counties. The county's population was reported by the U.S. Census to be 413,344 in 2010...
. 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.
The beetle's common name probably refers to the triangular marking on its pronotum. The species name, viridis, comes from the Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
word for green
Green
Green is a color, the perception of which is evoked by light having a spectrum dominated by energy with a wavelength of roughly 520–570 nanometres. In the subtractive color system, it is not a primary color, but is created out of a mixture of yellow and blue, or yellow and cyan; it is considered...
.
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 DixonDixon, California
Dixon is a city in northern Solano County, California, United States, located from the state capital, Sacramento. The population was 18,351 at the 2010 census. Other nearby cities include Vacaville, Winters and Davis....
, where it is protected; however, the beetle's other known ranges are located on public land.
The beetle occupies vernal pool
Vernal pool
Vernal pools, also called vernal ponds or ephemeral pools, are temporary pools of water. They are usually devoid of fish, and thus allow the safe development of natal amphibian and insect species...
habitats, around which its life cycle
Biological life cycle
A life cycle is a period involving all different generations of a species succeeding each other through means of reproduction, whether through asexual reproduction or sexual reproduction...
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 grassland
Grassland
Grasslands are areas where the vegetation is dominated by grasses and other herbaceous plants . However, sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica...
s, but the beetle's small size, camouflage
Camouflage
Camouflage is a method of concealment that allows an otherwise visible animal, military vehicle, or other object to remain unnoticed, by blending with its environment. Examples include a leopard's spotted coat, the battledress of a modern soldier and a leaf-mimic butterfly...
against spring grass, and tendency to hide beneath low growth make it difficult to locate.
Reproduction
The Delta green ground beetle breeds through February and March, with females producing one generation per year.Diet
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 ElaphrusElaphrus
Elaphrus is a genus of ground beetle native to the Palearctic, the Nearctic, the Near East and Northern Africa. It contains the following species:* Elaphrus americanus Dejean, 1831 * Elaphrus angulonotus Shi & Liang, 2008...
, it is likely that the beetle feeds primarily on springtail
Springtail
Springtails form the largest of the three lineages of modern hexapods that are no longer considered insects...
s.
Conservation status
The Delta green ground beetle's current IUCN Red ListIUCN Red List
The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...
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.