Worcestershire Record No. 3 November 1997 p. 9

HOLLY BLUES ARE HERE AGAIN

After hearing of many reports of Holly Blues this summer Worcestershire Wildlife Trust sent out a Media Release in July to draw attention to this interesting phenomenon. Coincidentally, Digby Wood of Butterfly Conservation (West Midlands Branch) had sent in an interesting article for the Trust's Newsletter Worcestershire Wildlife News.

The text of the MEDIA RELEASE was at follows:

After several years in which these attractive blue butterflies have been scarce they are back with a bang this year. Many were seen in gardens in April when the first brood hatched from over-wintering chrysalids. The spring butterflies laid their eggs on holly flowers. These have now completed their life cycles and high-flying blue butterflies are once again on the wing and busy searching round the holly and the ivy. The males are looking for the females and the females for suitable places to lay their eggs on ivy flowers which the summer caterpillars eat.

Harry Green of the Worcestershire Nature Conservation Trust said "Its very good to see these attractive butterflies about in large numbers this year. If you are lucky enough to find a caterpillar (which looks a bit like a tiny green slug) on a holly or ivy flower you may notice that it is often attended by ants which lick special secretions from small glands on the caterpillar's skin. Ants also attend the chrysalis for the same reward when it forms near the ground. The ants drive off parasites, especially small wasps that lay their eggs into the caterpillar which is then consumed from within. Despite the ants, the parasites get the upper hand in some years and holly blue numbers fall. This of course deprives the parasite of livelihood and butterfly numbers eventually rise again. Definitely a boom and bust lifestyle!

If you see a smart blue butterfly with pale underwings marked with a few black spots in your garden during July its probably a Holly Blue. Some of the biggest colonies are in towns and villages where there are gardens with plenty of holly and ivy. The Worcestershire Wildlife Trust would be interested to hear of sightings". The "story" was taken up by most local newspapers and radio and a surprising number of people contacted the Trust by phone. Droitwich turned out to be a mega-hot-spot for Holly Blues! The Droitwich response was in part provoked by the cartoon which appeared in the Droitwich Advertiser. Although a few records may have been lost, 80 people contacted the Trust and reported Holly Blues from the following places:

These calls from the public were the tip of an iceberg: there were very large numbers of Holly Blues around. Many callers reported up to ten in their gardens (one reported 20 in a Bromsgrove garden!), and every naturalist in the county mentioned "large numbers of Holly Blues!". The responses were mainly from North Worcestershire - even the Malvern record was from a man who lived in Bromsgrove. This does not reflect a lack of Holly Blues in South Worcestershire but reflects reaction to the newspaper cartoon and prominent Press coverage. It will be interesting to see what happens in 1998.