Ischnura gemina

(Kennedy, 1917)

San Francisco Forktail

Ischnura gemina is a small to the San Francisco Bay Area of California, with a total range of less than 500 square miles. It is considered one of the rarest odonates in the United States. The inhabits coastal wetland and has been observed to have an unusually long lifespan for a damselfly, likely an to the region's foggy climate. have declined due to urbanization and destruction, though the species shows some to certain forms of habitat degradation.

Ischnura gemina by the Smithsonian. Used under a CC0 license.

Ischnura gemina by JS Young. Used under a CC BY 4.0 license.

Pronunciation

How to pronounce Ischnura gemina: /ˈɪsk.nʊə.rə ˈdʒɛm.ɪ.nə/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

are approximately 2.5 cm in length. Males are mostly black with blue sides on the and blue dots toward the tip of the . Females have dull green coloration on the sides of the thorax. Distinguished from the similar Ischnura denticollis by the shape of the male genital appendages.

Images

Habitat

Coastal wetland of the San Francisco Bay Area, including seepages and ponds. Tolerates some disturbance such as channelization of waterways provided marshy vegetation cover remains. Larvae develop in the cover of aquatic plants.

Distribution

to the San Francisco Bay Area, California, United States. Occurs only in greater San Francisco and parts of San Mateo and Marin Counties. Total range less than 500 square miles.

Seasonality

Active between March and November. are known to live over 30 days, which is relatively long for .

Diet

feed on other wetland arthropods.

Human Relevance

Designated endangered on the IUCN Red List, later downgraded to vulnerable status. have been extirpated from some localities due to urbanization; reintroduction efforts at Glen Canyon Park in San Francisco initially succeeded but the population subsequently disappeared. The ' persistence at restored sites provides data about requirements.

Similar Taxa

Ischnura denticollisVery similar in appearance; distinguished by shape of male genital appendages. The two are thought to hybridize.