Holly Blue Celastrina argiolus

Habitat

The Holly Blue has extended its range northwards over the last few decades, now reaching as far as Cumbria. It is found in woody parks, churchyards and gardens, basking high on the foliage of trees, and feeding on the honeydew of aphids or salts from damp mud, rather than nectaring on flowers.

Identification

The male is violet-blue and can be confused with the Common Blue male. The female has distinctive black wing tips, and both sexes have pale blue undersides with black spots.

Flight times

Generally double-brooded further south, it is on the wing from late March to late June, and again from July to early September. Numbers fluctuate widely from year to year.

Food plants

Spring generation females lay their eggs on Holly buds, whilst the summer brood lay mainly on Ivy. Dogwood, Spindle and Pyracantha are also used.

Holly Blue
Holly Blue - © Simon Jenkins.

Distribution Maps

2005-2009
Holly Blue distribution map 2005-09
2010-14
Holly Blue distribution map 2010-14
2015-2019
Holly Blue distribution map 2015-19
2015
Holly Blue distribution map 2015
2015 Summary
No of tetrads 415
First sighting 05/04/2015
Last sighting 11/10/2015
2016
Holly Blue distribution map 2016
2016 Summary
No of tetrads 400
First sighting 12/04/2016
Last sighting 22/10/2016
2017
Holly Blue distribution map 2017
2017 Summary
No of tetrads 367
First sighting 27/03/2017
Last sighting 10/10/2017
2018
Holly Blue distribution map 2018
2018 Summary
No of tetrads 631
First sighting 21/04/2018
Last sighting 02/09/2018
2019
Holly Blue distribution map 2019
2019 Summary
No of tetrads 537
First sighting 20/03/2019
Last sighting 05/10/2019

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