Cause and Effect: Nelson's Hairstreak Butterflies

    In this late winter to spring, we have had a long series of sunny, dry days.  A few weeks ago I remarked to my fellow blog naturalists that with these conditions, this was going to be a going to be a good year for butterflies.  And so it has proved to be…

    Nancy was in our backyard on one sunny afternoon, goggling over all the pollinators that were clustered on our Ceanothus shrub.  She was focused on all the bees, but suddenly noticed a small brown butterfly, its proboscis extended, drinking deeply of the nectar provided by the tiny blue flowers.  She got some great photographs and came back in the house to share her discovery with me.  It was a Nelson’s or Cedar Hairstreak butterfly Callophrys nelsoni.

     This is a life butterfly for me, meaning I’d never seen it before.  I was very surprised to find it in our small city backyard.  The thing about butterflies is that they tend to flit into a garden, grab some nectar and move on.  But if you provide a key host plant for that butterfly, they might actually stick around your yard.  That is what happen with this Hairstreak.  .

     It turns out this hairstreak butterfly lays its eggs only on cedar trees.  The males will perch all day on cedar branches, waiting for females to come by.  When she arrives, they will mate, and then the female will lay single eggs on the tips of cedar branches.  This hairstreak uses both our native cedars Western Red and Incense Cedars, but will also use Cedar of Lebanon, native to the middle East.

     In our front yard is a old, very tall Cedar of Lebanon.  It is facing south and gets full sun, conditions which butterflies love.  We have lived at our place for eight years now;  it is my guess that in all these years, the Hairstreaks have been using our cedar as a host plant, then diving down into our pollinator garden to feed.   And we had never known about this butterfly.

     We are nature watchers and we are excellent observers.  Yet until this year, we missed the Hairstreak butterflies.  It just goes to show that there are always new things in nature and in our own backyard, to provide a rich source of amazement and learning...

Janet


Resources:
•  All photos by Nancy Partlow
•  A great blog on Washington Butterflies:
http://www.washingtonbutterflies.com/2013/01/june-butterflying-in-western-washington.html