Valley Elderberry Longhorn Beetle – What California Growers Need to Know
Blue elderberry, Sambucus nigra ssp. cerulea, (as well as red elderberry, Sambucus racemosa) is the obligate host for the Valley Elderberry Longhorn Beetle, meaning that it is the only known plant species that this beetle relies on for habitat and food. The Valley Elderberry Longhorn Beetle is listed as a threatened species under the federal Endangered Species Act, indicating that, while it is not in immediate danger of extinction, its populations have declined to the extent that federal regulations govern management of its habitat wherever it is found (US FWS 2017).
The beetle’s range encompasses the floor and adjacent lower foothills of the Central Valley, from approximately Shasta County in the north to Fresno County in the south. The majority of documented beetle occurrences have been below 500 feet elevation.
Although the beetle is not necessarily present in every elderberry tree, use of any given plant by the species is rarely apparent, since larvae typically stay burrowed inside the stem for long periods. Research has indicated that the most likely places to find the beetle are in healthy riparian systems supporting dense clumps of elderberry. Isolated elderberries far from such locations are not necessarily hosting the beetle, due to its relatively weak flying ability and poor long-distance dispersal capability. However, determining the presence of the beetle can be difficult and unreliable, because the only external signs are the holes where adults previously exited the stems.
Females lay eggs on leaves or at the junctions of leaf stalks and the main stem. Upon hatching, larvae bore into the elderberry stem, where they feed on the pith and undergo several developmental stages, which can last for up to two years. After pupating, the adults emerge from exit holes, feed on elderberry leaves and flowers, and mate and lay eggs, from March to July (US FWS 2017).
VELB male above SacRiver Jon Katz Joe Silveira USFWS
Because Valley Elderberry Longhorn Beetle larvae bore into elderberry stems, the following regulations apply to any elderberry plants within the Central Valley range of the beetle (US FWS 2017):
- Pruning or cutting of stems and plants: Elderberry stems larger than 1 inch in diameter may not be cut from the plant or removed from the site, and therefore plants with 1 inch stems or larger cannot be removed.
- Timing of trimming: Any required trimming (of stems less than 1 inch in diameter) should occur between November and February.
Harvesting of flowers or berries is not restricted in any way. Due to restrictions on trimming and removing plants, producers wishing to grow blue elderberry are advised to limit planting of elderberries to within hedgerows, where they will become part of a permanent conservation feature with no expectations of major pruning or tree removal required into the foreseeable future (unless the land has been entered into a Programmatic Safe Harbor Agreement, see below).
A few areas of the Central Valley provide landowners with alternative avenues for managing elderberry, through Programmatic Safe Harbor Agreements (PSHA). These agreements are typically made between the U.S. Fish and Wildlife Service (FWS) and an administering organization, such as a non-profit or other local community-based organization.
Locations of Safe Harbor Agreements:
Privately-owned properties in the following counties are covered by an agreement administered by the Sacramento River Forum (https://www.sacramentoriver.org/forum) since 2013:
Butte, Colusa, Glenn, Shasta, Sutter, Tehama, Yolo
This agreement allows private landowners to enter into cooperative agreements with the Sacramento River Forum to allow for more extensive management of elderberry trees – which may, for example, include pruning or removing large branches - free from fear of regulatory burdens, fines, or penalties. Agreements are subject to certain monitoring and reporting provisions to ensure that the number of elderberry trees on the property never falls below a baseline number that is established at the time of entry into the agreement. The overall goal of such Safe Harbor Agreements is to provide a net conservation benefit to threatened species by reducing the regulatory risk to landowners who wish to establish more habitat.
For more details about entering into a cooperative landowner agreement for one of the counties listed above, please consult the Sacramento River Forum website. The organization can also be reached at 2440 Main St., Red Bluff, CA 96080. Tel. 530-518-1011.
As of 2020, for properties immediately adjacent to Putah Creek and its tributaries, a Safe Harbor Agreement is available via the Solano County Water Agency. Contact Rich Marovich, Streamkeeper, at firstname.lastname@example.org, Tel. 707-455-1107.
Other Central Valley Counties:
For landowners in areas not covered above, contact a California office of the US Fish and Wildlife Service or USDA, such as via a local USDA Service Center, for assistance. In some cases it may be possible to obtain a disqualification from the applicable endangered species regulations, or a biological opinion that planting and managing elderberry in the proposed location will not adversely affect the Valley Elderberry Longhorn Beetle.
However, as long as growers or landowners are not intending any major management of elderberries (especially pruning of large branches) once planted, it is not necessary to join a Safe Harbor Agreement or contact any agencies before planting.