FWS Focus

Overview

Characteristics
Overview

The delta green ground beetle is currently known to live only in the Jepson Prairie region of Solano County. Rarely seen, adults are metallic green and bronze, and live near the edges of the prairie’s large vernal pools, which are called playa pools. The population size is unknown and locating individuals remains a challenge due to how little is understood about the beetle’s life cycle. 

The delta green ground beetle was listed as threatened on August 8, 1980 and is threatened by:

  • Small population size, in a limited range
  • Agricultural use of lands
  • Climate change that results in drying of vernal pools 
  • Non-native and invasive plant species that don’t provide the right cover

Scientific Name

Elaphrus viridis
Common Name
Delta Green Ground Beetle
FWS Category
Insects
Kingdom

Location in Taxonomic Tree

Identification Numbers

TSN:

Characteristics

Characteristic category

Food

Characteristics
Food

Based on observations of beetles in the field, researchers believe that delta green ground beetles are predators that feed on many different kinds of prey. The most important food source is believed to be springtails. The delta green ground beetle has also been observed eating larvae and adult midges, as well as beetle larvae of other undetermined species.

Characteristic category

Behavior

Characteristics
Behavior
Characteristic category

Physical Characteristics

Characteristics
Size & Shape

The delta green ground beetle is approximately 0.25 inches (0.6 centimeters) long.

Color & Pattern

The delta green ground beetle is typically brilliant metallic green and bronze. There are two slightly different color forms. Most adults are metallic green with bronze spots on the elytra, which is the first pair of wings, but some adults lack the spots and are nearly uniform metallic green. Larvae of the delta green ground beetle are seldom seen.

Characteristic category

Similar Species

Characteristics
Similar Species
Characteristic category

Life Cycle

Characteristics
Life Span

There is only one generation per year, but some early adults appear quite worn, which suggests that they may live at least one year and possibly even longer.

Reproduction

Adult females are thought to lay eggs once per year.

Life Cycle

Much about the delta green ground beetle’s life cycle remains unknown. Experts hypothesize that adults undergo a period of dormancy until the first warm days of late winter, when they emerge from underground homes and females lay their eggs. When the pools dry and the weather turns hot, the beetles go dormant again. Beetle larvae crawl into cracks in the soil to survive the hot, dry summer and fall as dormant pupae.

Characteristic category

Habitat

Characteristics
Habitat

The delta green ground beetle is found along the edges of vernal and playa pools, which are formed primarily on clay soil. Adults hide in cracks in the soil and beneath low vegetation during the wet season. They can be seen sunning on bare prairie during their active months. During the dry seasons of summer and fall, experts hypothesize that the beetle larvae survive the heat by resting dormant in cracks in the soil.

Grassland

Land on which the natural dominant plant forms are grasses and forbs.

Rural

Environments influenced by humans in a less substantial way than cities. This can include agriculture, silviculture, aquaculture, etc.

Wetland

Areas such as marshes or swamps that are covered often intermittently with shallow water or have soil saturated with moisture.

Geography

Characteristics
Range

The historical range of the delta green ground beetle is unknown. It is currently only found in the Jepson Prairie region of Solano County.

Launch Interactive Map

Timeline

Explore the information available for this taxon's timeline. You can select an event on the timeline to view more information, or cycle through the content available in the carousel below.

10 Items

Critical Habitat

Listing

Critical Habitat

Critical Habitat

Listing

Recovery Plan

Five Year Review

Five Year Review

Five Year Review

Five Year Review

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Critical Habitat

Aug 10, 1978

Aug 10, 1978 Critical Habitat
Proposed Endangered or Threatened Status and Critical Habitat for Ten Beetles
  • Publication type: Proposed
Item 1

Listing

Aug 10, 1978

Aug 10, 1978 Listing (Threatened)
Proposed Endangered or Threatened Status and Critical Habitat for Ten Beetles
  • Publication type: Proposed
Item 2

Critical Habitat

May 2, 1980

May 2, 1980 Critical Habitat
ETWP; Reproposal of Critical Habitat for the Delta Green Ground Beetle
  • Publication type: Proposed
Item 3

Critical Habitat

Aug 8, 1980

Aug 8, 1980 Critical Habitat
Listing the Delta Green Ground Beetle as a Threatened Species with Critical Habitat
  • Publication type: Final
Item 4

Listing

Aug 8, 1980

Aug 8, 1980 Listing (Threatened)
Listing the Delta Green Ground Beetle as a Threatened Species with Critical Habitat
  • Publication type: Final
Item 5

Recovery Plan

Nov 18, 2004

Nov 18, 2004 Recovery Plan (Document Availability (non-FR))
Draft Recovery Plan for Vernal Pool Ecosystems of California and Southern Oregon
  • Publication type: Draft
Item 6

Five Year Review

Mar 22, 2006

Mar 22, 2006 Five Year Review (Information Solicitation)
Initiation of 5-Year Reviews of 56 Species in California and Nevada: Notice of review.
  • Publication type: Notice
Item 7

Five Year Review

May 21, 2010

May 21, 2010 Five Year Review (Completion)
Initiation of 5-Year Reviews of 34 Species in California and Nevada; Availability of 96 Completed 5-…
  • Publication type: Notice
Item 8

Five Year Review

Apr 1, 2013

Apr 1, 2013 Five Year Review (Information Solicitation)
Initiation of 5-Year Reviews of 56 Species in California and Nevada; request for information
  • Publication type: Notice
Item 9

Five Year Review

Feb 10, 2020

Feb 10, 2020 Five Year Review (Information Solicitation)
Initiation of 5-Year Status Reviews of 66 Species in California and Nevada; request for information
  • Publication type: Notice
Item 10