FWS Focus

Overview

Characteristics
Overview

The valley elderberry longhorn beetle is a medium-sized, red and dark green insect. It is approximately 0.8 inch (2 centimeters) long. Females are larger than males and resemble males except that the first pair of wings do not fully cover the abdomen when viewed from above. Males have longer, thicker antennae than females, as well as red-orange wing covers with four spots. 

The valley elderberry longhorn beetle lives throughout California’s Central Valley from Shasta County in the north through Madera County in the south. Destruction of riparian riparian
Definition of riparian habitat or riparian areas.

Learn more about riparian
forests during the past 150 years fragmented the beetle’s habitat, and it is likely less widespread than in the past.

The valley elderberry longhorn beetle is dependent on its host plant, the elderberry, a shrub that grows in riparian areas and foothill oak woodlands in California. Females lay their eggs on the bark of the elderberry shrub. Larvae hatch and burrow into the stems. Larvae take one to two years to emerge as adults. Adults only live from a few days to a few weeks after emerging and likely die within three months. The valley elderberry longhorn beetle was listed as threatened on August 8, 1980.

The largest threats to the species include: 

  • Loss and fragmentation of habitat due to agricultural and urban development
  • Destruction of host shrub due to maintenance and construction of levees and highways
  • Drought and flooding resulting from climate change climate change
    Climate change includes both global warming driven by human-induced emissions of greenhouse gases and the resulting large-scale shifts in weather patterns. Though there have been previous periods of climatic change, since the mid-20th century humans have had an unprecedented impact on Earth's climate system and caused change on a global scale.

    Learn more about climate change
  • Invasive plants that outcompete the elderberry shrub
  • Invasive non-native Argentine ant which competes with and eats the beetle
  • Pesticide use on elderberry shrubs

Scientific Name

Desmocerus californicus dimorphus
Common Name
valley elderberry longhorn beetle
FWS Category
Insects
Kingdom

Location in Taxonomic Tree

Identification Numbers

TSN:

Characteristics

Characteristic category

Habitat

Characteristics
Habitat

The valley elderberry longhorn beetle lives throughout California’s Central Valley from Shasta County in the north through Madera County in the south. Destruction of riparian riparian
Definition of riparian habitat or riparian areas.

Learn more about riparian
forests during the past 150 years fragmented the beetle’s habitat, and it is likely less widespread than in the past.

The valley elderberry longhorn beetle is dependent on its host plant, the elderberry, a shrub that grows in riparian areas and foothill oak woodlands in California. While these shrubs are widely distributed, the valley elderberry longhorn beetle is only found on the valley floor and low foothills.

When the valley elderberry longhorn beetle was listed in 1980, it was known from just 10 observations at three locations: the Merced River in Merced County, the American River in Sacramento County and Putah Creek in Yolo County. Today, there are approximately 190 records of the beetle in the Central Valley. These records are largely based on observations of holes in the stems of the elderberry host shrub which are created by adult beetles as they emerge from the shrub to mate and feed.

Forest

A dense growth of trees and underbrush covering a large tract.

River or Stream

A natural body of running water.

Characteristic category

Physical Characteristics

Characteristics
Size & Shape

The valley elderberry longhorn beetle is a medium-sized, red and dark green insect. It is approximately 0.8 inch (2 centimeters) long. Females are larger than males and resemble males except that the first pair of wings do not fully cover the abdomen when viewed from above. Males have longer, thicker antennae than females, as well as red-orange wing covers with four spots. 

Characteristic category

Food

Characteristics
Food

The valley elderberry longhorn beetle feeds exclusively on the elderberry shrub throughout all stages of its life. Larva feed on the pith of the stems. Adult beetles emerge from the pith just as the shrub begins to bloom. Adults feed on the leaves and flowers, and nectar, of the host plant. The shrub blooms from March through early June.

Characteristic category

Life Cycle

Characteristics
Life Cycle

The valley elderberry longhorn beetle lives one to two years. Females lay their eggs on the bark of the elderberry shrub. Larvae hatch and burrow into the stems. Larvae are active within the stems year-round and take one to two years to emerge as adults. Adults are active from March until June. Adults only live from a few days to a few weeks after emerging and likely die within three months.

Geography

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Timeline

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