Wooly Adelgid.

9-23-10 SHORT HILLS: The Equinox has past and we’re back on the dark side of the year until March, 2011. Yesterday and today were in the eighties, and we had a T-storm last night which gave us 0.25 inches to go with the 0.5 inches when we returned a few days ago. That last was from the storm that became a tornado in Brooklyn and Queens. We had one big branch down that came off a white ash. I cut it into about a dozen pieces of firewood, the largest of which is just small enough not to need splitting. Tomorrow might get to a record-breaking 90°, not exactly fallish.

Yesterday was quite exciting in the yard, first the sprinkler people finished their repair, then the gardeners mowed and the tree sprayers arrived in the afternoon to treat the hemlocks for wooly adelgid.

Wooly adelgid is a hemlock, Tsuga canadensis, parasite. It used to be classified as a protozoan, but, I believe, it is now called a true bug, Adelges tsugae. They look like little bits of cotton stuck to the undersides of hemlock needles. They can suck the tree dry if untreated. We have lost a few small trees to the disease, and having several in the yard, are concerned about saving the rest. The spraying is done spring and fall. Mineral oil, plain old mineral oil, coats the parasite and smothers it, at least to keep it in check. Some nasty pesticides may be used, we avoid them because of the dogs, and people.


Hemlock needles are flat and have a pair of stripes on the underside. The cones are small and droop from the ends of small branches. The white stuff is the parasite.

Photomicrograph of the bug. Yuck.


The big picture is from Wikipedia. The two smaller ones from a Google search.