On April 5th, Denbies vineyard had a visit from the Butterfly Conservation team, who are working on a project to help the Small Blue Butterfly in Surrey. This species is far less widespread than it once was for various reasons, the primary one being a serious shortage of its foodplant, Kidney Vetch. The larvae feed solely on this on plant and specifically need the flowers, which they live amongst and also feed from the developing seeds. Kidney Vetch is a plant which requires bare ground that gets some disturbance, therefore doesn’t do well when a dense sward of grasses and scrub develops. The plant always did quite well when there were active chalk quarries in the area and when there was more chalk downland and less woodland and built-up areas. We have populations of Small Blue at Box Hill and at Pewley and Merrow Downs and the Butterfly Conservation team are trying to link these populations by creating lots of great habitat between them. Bare ground patches will be required to sow locally sourced Kidney Vetch seed directly into and these areas will need management in the first few seasons. Additional bare areas will need to be created in the future, to encourage the plant to spread. Small patches of bare ground have been cleared for the most part here on the vineyard, due to the fact that we already have a diverse range of important caterpillar foodplants growing on the bank. These include:-
Horseshoe Vetch – foodplant for Adonis Blue and Chalkhill Blue butterflies
Common Rock Rose – foodplant for Brown Argus
Salad Burnet – foodplant for Grizzled Skipper
Marjoram – Lace Border Moth foodplant
These are some of the other species that the Butterfly Conservation hope to encourage through the project, along with the Silber Spotted Skipper and Dingy Skipper butterflies. Considerable habitat management has been undertaken at nearby sites including Denbies Hillside, Hackhurst Downs, Newlands Corner, Shere Woodlands and Brockham Quarry.
With the ground cleared, the Butterfly Conservation will be back with seeds in the next few weeks. Hopefully this will germinate well and maybe next summer we will have flowering Kidney Vetch. Being so close to Box Hill, there is every chance that the vineyard will support the butterfly in the future.