Hampshire and Isle of Wight Butterfly and Moth Society
Hampshire and Isle of Wight Butterfly and Moth Society
| Family: | Lycaenidae |
| Subfamily: | Polyommatinae |
| Genus: | Polyommatus |
| Species: | bellargus |
| Authority: | (Rottemburg, 1775) |
The Adonis Blue is a species of chalk downland, where it may be found in warm, sheltered spots. The male Adonis Blue has brilliantly-coloured blue wings that gives this butterfly its name, and can be found flying low over vegetation, seeking out the less-conspicuous females that are a rich chocolate brown in colour. Like its close relative, the Chalk Hill Blue, the distribution of this species follows the distribution of Horseshoe Vetch which, in turn, follows the distribution of chalk and limestone grassland. However, this species has a more restricted distribution than the Chalk Hill Blue, indicating more precise habitat requirements. This butterfly can be found in large numbers where it does occur, such as the chalk downloads of Dorset, South Wiltshire, West Sussex, East Sussex and East Kent. This species is absent from central England, northern England, Wales, Scotland, Ireland, the Isle of Man and the Channel Islands. This species lives in discrete colonies.
| #Individuals | #Tetrads | 2022 | 2023 | Abundance Trend | 2022 | 2023 | Distribution Trend |
|---|---|---|---|---|---|
| 987 | 1054 | +6% | 30 | 28 | -6% |
| #Records | #Individuals | Earliest Record | Latest Record | |
|---|---|---|---|---|
| All Records | 7,703 | 38,647 | 26/04/2011 | 15/10/2011 |
| 2023 | 284 | 1,054 | 17/5/2023 | 29/9/2023 |
| Location | Date | Quantity | |
|---|---|---|---|
| Earliest Record | Arreton Down | 17/5/2023 | 1 |
| Latest Record | Magdalen Hill Down Original transect: Section 1 | 29/9/2023 | 1 |
| Highest Count | Compton Down | 27/5/2023 | 51 |
One of the issues with 'raw' trend data is that there is inherent bias based on the number of recorders. For example, the number of individuals and populated tetrads recorded are likely to increase if there is an increase in the number of recorders. In order to remove this bias, the normalised trends use data that has been recalculated using the average number of recorders over the trend period. This normalisation gives a much better picture of the true trends.
Average #Recorders: 40.24
Average #Recorders: 40.24