Hampshire and Isle of Wight Butterfly and Moth Society
Hampshire and Isle of Wight Butterfly and Moth Society
| Family: | Pieridae |
| Subfamily: | Coliadinae |
| Genus: | Gonepteryx |
| Species: | rhamni |
| Authority: | (Linnaeus, 1758) |
It is commonly believed that the word "butterfly" is a derived from "butter-coloured fly" which is attributed to the yellow of the male Brimstone butterfly, the female being a much paler whitish-green. The Brimstone has a most exquisite wing shape, perfectly matching a leaf when roosting overnight or hibernating within foliage. This is one of the few species that hibernates as an adult and, as such, spends the majority of its life as an adult butterfly. The distribution of this species closely follows that of the larval foodplant. In England, where it is represented by the subspecies rhamni, it can be found south of a line from Cheshire in the west to South-east Yorkshire in the east, although vagrants may turn up in other areas. In Ireland, where it is represented by the subspecies gravesi, its strongholds are in a small area that lies between the borders of West Galway, West Mayo and East Mayo, and a band running through central Ireland from Clare in the west to Kildare in the east.
| #Individuals | #Tetrads | 2022 | 2023 | Abundance Trend | 2022 | 2023 | Distribution Trend |
|---|---|---|---|---|---|
| 14731 | 27488 | +86% | 680 | 814 | +19% |
| #Records | #Individuals | Earliest Record | Latest Record | |
|---|---|---|---|---|
| All Records | 130,449 | 303,089 | 01/01/2001 & 2022 | 29/12/1999 |
| 2023 | 11,323 | 27,488 | 2/1/2023 | 28/11/2023 |
| Location | Date | Quantity | |
|---|---|---|---|
| Earliest Record | Thorness Bay | 2/1/2023 | 1 |
| Latest Record | Poulner | 28/11/2023 | 1 |
| Highest Count | Stockbridge Down | 25/7/2023 | 112 |
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: 555.04
Average #Recorders: 555.04