Charlie Burnham Report: November, 2008

DCR Forester Charlie Burnham visited Hemlock Gorge in November, 2008. Here are his reports to the Friends:

I went to the gorge to evaluate it as a possible release site for a different predatory beetle, Laricobius nigrinus. I noticed that the hemlocks were in two very different states of health which I can’t explain. Some of the trees have full crowns and a nice green foliage color, exactly what a hemlock is suppose to look like. Other trees have a thinning crown; and are kind of off color. These two different states of tree health are in some cases right next to each other which would rule out site or environmental factors. As for the adelgid the populations are extremely low at least on the branches I could reach so the site did not meet the needs of the new predator program. One other thing I notice is that there is an increase in the population of elongate hemlock scale which can cause tree decline and mortality especially when coupled with another stress factor like adelgid, drought, or soil compaction.

I would like to think the ladybugs are still present at the Gorge and for the past several years intended to do some sampling, but other things seem to be higher on the priority list, maybe next spring or summer.

The other predator is native to the Pacific Northwest, some of the insects we had available were collected in Washington and Idaho. Virginia Tech is doing some lab rearing also. We haven’t given up on the ladybugs but we just don’t want to have all our eggs in one basket.

As for the Asian Longhorned Beetle, given the fact that it has been in Worcester for 7-plus years I suspect it has been spread through the movement of infested wood without anyone knowing it, but I hope for the sake of the New England forests it is contained in Worcester.