ÿþ<html> <head> <title>Regional Species - Holly Blue</title> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> <meta name="keywords" content="Holly Blue, Celastrina argiolus"> <meta name="description" content="The Holly Blue butterfly in North Wales"> <LINK REL="StyleSheet" HREF="../../branch.css" type="text/css"> <SCRIPT language="JavaScript"> <!-- if (parent.location.href == self.location.href) window.location.href = "../../index.html?species/holly_blue/index.html"; // --> </SCRIPT> </head> <body class="background"> <a name="top"></a> <table border="0" cellspacing="0" cellpadding="0" align="center" width="100%"> <tr> <td width="1" bgcolor="#cccccc"><img src="../../images/dot.gif" border="0" width="1" height="1"></td> <td valign="top" class="content"> <blockquote> <SPAN class="page-title">Regional Species</SPAN> <br><br><br> <SPAN class="article-subtitle">Holly Blue</SPAN><br><SPAN class="scientific-name">Celastrina argiolus</SPAN> <br><br> <table border="0" cellpadding="4" cellspacing="0" width="408"> <tr><td><img src="photo_1.jpg" width="400" height="296" alt=" Holly Blue " border="2"></td></tr> <tr><td><h5>Photograph by Janet Graham (Breidden Forest)</h5></td></tr> </table> </blockquote> </td> <td valign="top" class="content"> <!-- NAVIGATION ELEMENT - BACK TO SPECIES INDEX PAGE --> <table border="0" cellpadding="2" cellspacing="0"> <tr> <td><a href="../index.html" onFocus="this.blur();"><img src="../../images/right.gif" width="19" height="19" border="0"></a></td> <td class="links"><a href="../index.html">Regional Species</a></td> </tr> </table> <br clear="all"> <p>&nbsp;</p> <SPAN class="subtitle">About the Holly Blue</SPAN> <p class="content">This butterfly is usually seen in lowland districts, flying around trees and shrubs at, or above, head height. It is not unusual to see the butterflies flying high in the canopies of mature oak trees, in which situation they can be confused with Purple Hairstreaks. </p> <p class="content">The butterfly is bivoltine with the spring brood laying on holly and the autumn brood on ivy. The winter months are passed in the pupal stage. </p> <p class="content">The species is well known for experiencing a cyclic variation in population size and this phenomenon has been very noticeable in North Wales over the last decade or so. Numbers were very high in 1998/99 with another, lesser, peak in 2004/05. Numbers seem, subjectively, to have been up again in 2010/11 though the data does not currently seem to support this conjecture, possibly due to reduced recording effort in recent years.</p> <p class="content">The Holly Blue is not difficult to identify due to the pale, almost unspotted underside and the habit of flying higher than other blues. In March and April this is the only blue butterfly likely to be seen.</p> <p class="content">&nbsp;</p> <p class="content">Further information available from the <a href="http://www.trawsgoed.com/nwleps.aspx?tp=but&Let=H" target="noframe"> NW Lepidoptera Database</a>, including access to detailed records, maps, flight-time charts and photographs.</p> </td> </tr> <tr><td colspan="3" class="sidebar">&nbsp;&nbsp;&nbsp;<img src="../../images/top.gif" width="10" height="10" hspace="4" border="0"><a href="#top"><SPAN class="thispage">Top of page</SPAN></a> | <a href="../index.html"><SPAN class="thispage">Regional Species</SPAN></a></td></tr> <tr><td colspan="3" align="right"> <table border="0" cellpadding="10" cellspacing="0"><tr><td align="right"><h5><SCRIPT language=JavaScript src="../../_scripts/copyright.js"></SCRIPT></h5></td></tr></table> </td></tr> </table> </body> </html>