Celastrina

Tutt, 1906

Holarctic Azures

Species Guides

9

Celastrina is a of small butterflies in the Lycaenidae, commonly known as the Holarctic Azures. The genus is distributed across the Palearctic, Nearctic, Indomalayan, and Australasian realms. within this genus are typically associated with specific plants, with larvae showing varying degrees of dietary specialization. Several species have been studied in detail for their ecological relationships, including facultative mutualisms with ants.

Celastrina neglecta by (c) botanygirl, some rights reserved (CC BY), uploaded by botanygirl. Used under a CC-BY license.Celastrina neglecta by (c) Christine Betts McAnlis, some rights reserved (CC BY), uploaded by Christine Betts McAnlis. Used under a CC-BY license.Celastrina by (c) SteveM4560, some rights reserved (CC BY), uploaded by SteveM4560. Used under a CC-BY license.

Pronunciation

How to pronounce Celastrina: /sɛˈlæstrɪnə/

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

Images

Habitat

Varies by . Celastrina humulus is associated with riparian areas supporting its plant wild hops (Humulus lupulus). Celastrina gigas has been recorded from riverbed in the eastern Himalayas.

Distribution

Palearctic, Nearctic, Indomalayan, and Australasian realms. Specific records include: North America (Colorado, Montana, California, Oregon, eastern United States), Europe, Japan, Korea, China (including Tibet and Taiwan), Nepal, northeast India, Burma, Philippines, Borneo, Papua New Guinea, and the western Himalayas.

Seasonality

Spring activity documented for some North American . Celastrina ladon (spring azure) and Celastrina lucia (Lucia azure) are among the earliest-emerging butterflies in spring in their respective ranges. Celastrina humulus larvae have been monitored during plant flowering from 2020–2022.

Diet

Larvae of Celastrina humulus feed on pollen-bearing inflorescences of Humulus lupulus var. neomexicanus. Larvae of Celastrina argiolus (holly blue) have been documented utilizing plants in 19 different , showing exceptional dietary breadth within the .

Host Associations

  • Humulus lupulus - larval plantwild hops; specific association documented for C. humulus

Life Cycle

Complete with , larval, pupal, and stages. Larval development of Celastrina humulus occurs on plant inflorescences, with performance varying by phenological stage of the host plant.

Behavior

Celastrina humulus larvae engage in a facultative mutualism with ants, where the likelihood of tending varies with plant flowering . Ant recruitment is reduced on early-stage host plant inflorescences despite these stages enabling greater larval weight gain. butterflies are described as small, active, and difficult to photograph due to persistent flitting and skittish .

More Details

Ant-plant-herbivore interactions

Research on Celastrina humulus demonstrates that -plant can indirectly mediate herbivore through effects on mutualist recruitment. Early-stage host plant inflorescences contain higher concentrations of soluble proteins and α-acids, which enhance larval growth but simultaneously reduce ant attraction.

Conservation status

Celastrina humulus is considered rare in Colorado and Montana despite being locally abundant at specific sites such as the U.S. Air Force Academy. Patch extinction and probabilities for this are extremely low, suggesting stable where suitable exists.

Tags

Sources and further reading