Gomphus lynnae

Endemic to the United States. Known from five counties within the states of Oregon and Washington.

endemic to a single nation

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: (250-5000 square km (about 100-2000 square miles)) Known only from a short stretch (about 20 mi) of the Yakima River for a quarter century (Paulson 1983, 1996) and relatively recently discovered over a fairly short stretch (about 15 mi) of the North Fork of the John Day River in Oregon (Valley 1993) and at one locality on the Owyhee River (J. Johnson, pers. comm.; specimen examined; Johnson, 2002). One of the most restricted known ranges of any North American odonate.

Length: 5.5 cm

The only northwestern gomphid with a dark stripe along the rear edge of the thorax. Male cerci straight in side view, female vertex with a pair of slender spines. Larva not formally described but with lateral abdominal spines of segment 9 shorter than segment 10.

Habitat and Ecology

Systems

• Terrestrial
• Freshwater

Comments: Found in sandy to rocky, slow-flowing rivers; eggs broadcast in water, larvae burrow in mud, adults forage among shrubs.

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 1 - 5

Comments: Only five populations are known, one on the Yakima River (Benton County) in Washington, one on the Owyhee River (Malheur County) in Oregon, and three on the John Day River system (Grant County) in Oregon. The rivers on which it occurs are rather different habitats, so it should occur over a range of river systems, including in Idaho, but not found elsewhere in region yet (Abbott, 2007).

2500 - 10,000 individuals

Comments: Probably thousands of individuals in each of the three rivers where known.

Comments: Larvae overwinter, flight season mid May to mid July.

The following is a representative barcode sequence, the centroid of all available sequences for this species.

No available public DNA sequences.

Download FASTA File

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 2
Specimens with Barcodes: 2
Species With Barcodes: 1

Year Assessed

Assessor/s

Reviewer/s

Justification

History

• 1996
  Endangered
• 1996
  Endangered
• 1994
  Rare
  (Groombridge 1994)
• 1990
  Rare
  (IUCN 1990)

United States

Rounded National Status Rank: N1 - Critically Imperiled

Rounded Global Status Rank: G1 - Critically Imperiled

Reasons: Only known from two rivers in Oregon and one in Washington, where populations have declined. IUCN lists this as Endangered and the population trend as decreasing. One of three known occurrences is a river in an arid agricultural area with many uses/impacts (Abbott, 2007).

Population

Population Trend

Global Short Term Trend: Decline of 10-30%

Comments: Abbott (2007) states that the populations in the Yakima River, the only Washington site, have declined. However, he also states that it is not known to have declined in the Yakima for 31 years and the John Day for four years since discovery. Populations at the only two Oregon riveers seem to be stable. The IUCN assessment has this species as Endangered and the population trend as decreasing.

Global Long Term Trend: Increase of 10-25% to decline of 30%

Comments: Recent discovery of specimens in the Oregon State University Entomology Collection date occurrence of this species in the Owyhee River, Rome, Oregon, back 19 years before the species was "discovered" on the Yakima River, Washington; and 46 years before it was known to occur in the Owyhee River basin (Johnson, 2002).

Degree of Threat: Unknown

Comments: No threat known at present but pesticides entering rivers and dams with accompanying siltation, as well as introduced fish species could threaten. Presumably, overgrazing, fires, and pollution are the major threats to the watersheds where it is found (Dunkle, 2004).

Major Threats

Conservation Actions

Biological Research Needs: (1) Details on habitat preference of larva; (2) dispersal ability of adults; (3) formal description of larva.

Global Protection: None. No occurrences appropriately protected and managed

Comments: No protection whatsoever in the three river stretches with EOs.