Sloe Hairstreak

Satyrium acaciae (Fabricius, 1787)



A small dark brown butterfly. Male and female are similar, although the females is slightly larger and has a few orange spots on the hindwing upperside. The butterfly has one brood a year. It can be easily confused with members of the genius. The tail on the hindwing is indistinct which helps separate it from other members of the genius. On the underside, the postdiscal white line (hairstreak) forms a linear curve. Females have a distinctive black 'cap' to their abdomens.

Habitat Requirements

We know very little about the ecology of this species, see observations, but presumably its found in scrubby habitat.

Larval Foodplants

Blackthorn/Sloe Prunus spinosa.


An easily overlooked butterfly because it looks superficially similar to the Ilex Hairstreak.

Only two members of CBC have recorded sightings of this species, the first was Steve Young who photographed an imaculate female nectaring on Scabious on 22 May 2017. The second sighting came from Bob Giles who photographed a different female nectaring on Chamomile on 2 June 2017. Both observations were made in Loutses. 

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

First and Last Sightings

Year First Last/latest # Days
2022 30/05/2022 08/06/2022 9 days
2021 18/05/2021 10/06/2021 23 days

Number of Observations

Year Number of observations
2023 0
2022 28
2021 24
Grand Total 52

Distribution Map

Distribution maps for this species are currently unavailable.

Flight Times for the Sloe Hairstreak (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 Sloe Hairstreak (All Data)

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


  • Vernacular/Common Name: Sloe Hairstreak
  • Family: Lycaenidae (Leach, 1815)
  • Sub-family: Theclinae (Swainson 1831)
  • Tribe: Eumaeini (Doubleday 1847)
  • Genus: Satyrium (Scudder, 1876)
  • Sub-genus: Satyrium (Scudder, 1876)
  • Species: acaciae (Fabricius, 1787)


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