Geranium Bronze

Cacyreus marshalli Butler, 1898

Status

Description

 A small butterfly with a dark brown upperside, and olive-brown with lighter bands underside. Females are larger than males, but otherwise similar. The wing margin is chequred, and there is a black spot by the tiny tail on both sides of the hindwing. Whilst the underside of the wings are distinctive, they could be confused with Lampides boeticus and Leptotes pirithous, which have some similarity, and both have an obvious tail on the hindwing. 

Habitat Requirements

Most commonly enountered where its cultivated host plant is grown, i.e. towns and gardens. However, Dan Danahar has encountered a courting pair in rurual environs away from human habitation. suggesting that perhaps this species also utilises other host plants, e.g. Geranium molle.

Larval Foodplants

Geranium asphodeloides, Geranium brutium,Long-stalked Crane's-bill Geranium columbinum, Cut-leaved Crane's-bill Geranium dissectum, Shining Crane's-bill Geranium lucidum, Dove's-foot Crane's-bill Geranium molle, Little-Robin Geranium purpureum, Herb Robert Geranium robertianum, Round-leaved Crane's-bill Geranium rotundifolium, Bloody Crane's-bill Geranium sanguineum, Pelargonium Pelargonium peltatum planted for ornament.

Observations

A butterfly that has its origins in South Africa, that has spread with the human aided distribution of its host plant, Pelargonium, also found originally in South Africa. However, the spread of this species through Europe has only really occured during the last twenty to thirty years, probably helped by climate change.

The first record of this species from Corfu was made in 2009. Dan Danahar recorded it widely in Paleokastritsa during 2010, where he observed an apparent preference for oviposition on pink rather than red flowering Pelargoniums. Since this time it has spread widely thoroughout the island. It is considered a pest species of Pelargonium cultivars by horticulturalists but butterfly enthusuasts in Corfu have welcomed its presence in their gardens.

*The information provided in the tables below is based on verified sightings of the Geranium Bronze submitted via this website since 1st January 2021.

First and Last Sightings

Year First Last/latest # Days
2023 13/01/2023 08/06/2023 146 days
2022 15/03/2022 12/12/2022 272 days
2021 16/03/2021 11/11/2021 240 days

Number of Observations

Year Number of observations
2023 22
2022 234
2021 50
Grand Total 307

Distribution Map

Distribution maps for this species are currently unavailable.

Flight Times for the Geranium Bronze (2023)

The chart below shows flight data by month for 2023 submitted online since 1st January 2023 to 8th June 2023.

Flight Times for the Geranium Bronze (All Data)

The chart below shows flight data by month based on all data submitted online since 1st January 2019 to 8th June 2023.

Taxonomy

  • Vernacular/Common Name: Geranium Bronze
  • Family: Lycaenidae (Leach, 1815)
  • Sub-family: Polyommatinae (Swainson 1831)
  • Tribe: Polyommatini (Swainson 1831)
  • Sub-tribe: Cacyreina ()
  • Genus: Cacyreus (Butler, 1898)
  • Species: marshalli Butler, 1898

References

For a list of references, please see our bibliography page.