It was a fairly good year for the Black Hairstreak locally. It was reported from 10 new tetrads which included 3 new sites within the Upper Thames area.

Numbers at most sites were lower than in 2007. About ten isolated sites have returned no sightings for many years and give rise to concerns over their persistence.

More extensive surveying is required in several areas of the butterfly's known distribution, especially to ascertain the viability of several colonies now only known from old records and to determine the limits of each colony.

Black Hairstreak - 1st instar larva
Photo © Dave Wilton

Egg searches have shown that egg laying occurs at all heights within blackthorn scrub. No particular preference vis-à-vis oviposition sites has been detected.

Distribution map © Butterfly Conservation, Upper Thames Branch

The 2008 distribution of Black Hairstreak (Satyrium pruni)

Contact has been maintained at all key sites and established at some new sites, though some owners still need to be identified, so that management advice can be passed on. A detailed report on the last ten years of research has been produced.