The smallest British butterfly favouring small patches of kidney vetch. Very limited in range.
Small Blue: hide and seekPost date: Wednesday, 20 May, 2015 - 00:00
Small Blue in Dorset: what your tweets tell us ...Post date: Tuesday, 23 April, 2019 - 21:13
The small blue is certainly small, it is the smallest of our British butterflies, but it is not blue; both sexes are brown with the male being a darker, bluish brown. Although somewhat plain I think they are a delicate and quite attractive little insect. They have a preference for calcareous grasslands where kidney vetch and horseshoe vetch are present; the female lays her eggs only on kidney vetch. The males spend a lot of time resting on bushy vegetation ready to ward off other males whilst waiting patiently for a female to come within range. Because of their lack of activity and their small size they can be easily overlooked but, in any case, they are not a common species although they seem to be doing quite well in Dorset.
Small blue fly from mid May until the end of June and then often have a second brood in late July and August. The reports for 2017 and 2018 from Dorset tweeters surprisingly shows two records for week 16 at the end of April with records starting in earnest in week 19, mid May, in line with the text books. There are then records for every week until week 22 in mid-June and then just one in week 28 at the end of July which will be a second brood adult. There are currently only 19 reports for the two years combined so it is difficult to draw too many conclusions.
There are records, which include some from other survey data, from twenty four sites in Dorset which does demonstrate that it is doing well here. Portland and the Purbeck coast are good for them but the real bonus is a strong colony establishing itself along the new Weymouth relief road that was built for the 2012 Olympics; kidney vetch now occurs along this road's embankments in abundance and it seems small blue have responded well to that. Other sites occur along the chalk spine that runs from the Bridport area north-eastwards towards the Wiltshire border near Cashmoor.
|Common Name||Small Blue|
|Scientific Name||Cupido minimus|
|Species Group||Lycaenid Butterflies Blues and Hairstreaks|
|Additional Identification Notes|