I went out last week to look for a tree, a rather specific tree, in the forest behind our home. I hoped to see this tree again.  I first saw it last summer when the trees were still in leaf.  Now in the winter, on a subzero morning, making my way on snowshoes, everything looked quite different.  A Maine state forester had pointed out the tree while he was walking our property line with us.  It is a healthy beech tree (Fagus grandifolia), a bit more than a foot in diameter with beautiful bark that reminds me of a young elephant’s skin (or at least what I imagine it would look like). We had been talking about how sick our beech trees were and the peculiar nature of the disease killing them.   Beech trees where we live all suffer from beech bark disease caused by the beech bark scale.  Their bark looks like a terrible case of acne as the trees slowly die, rotting away at their core.

Beech bark scale, Cryptococcus fagisuga, is an odd little insect.  It only exists as females: no males have ever been found by persons able to identify them.  The females reproduce parthenogenically, that is without needing fertilization. They produce one brood a year, the eggs hatching in early summer.  During their first summer, they crawl about finding a nice cozy crack in a tree’s bark to inhabit. They molt, overwinter and in their second season emerge as soft legless non-mobile little creatures that adhere to their chosen spot on the tree. They use a kind of snout sucker to pierce cells deep in the tree and live off nutrients they suck up from cells deeper in the tree.  They hide themselves under a covering of secreted whitish wax.