Editor's note: Get Growing, written by the La Plata County Extension Office's Master Gardener Program, appears every other week during the growing season. It features timely tips and suggestions for your garden and landscape.
There is a new pest in the area, and he has quite the appetite. The European elm flea weevil (Orchestes alni) has decided to take up shop in our community, and it doesn't look like it will be leaving any time soon.
In the last month, my office has been flooded with calls about "something is eating my elm" or "it looks like someone stood underneath my tree and discharged a shotgun."
Oddly enough, the pest seems to be interested only in the Asian elms in our area - Chinese and Siberian - and not the majestic American elm. Many of us tend to have a love-hate relationship with Siberian elms, which seem to dominate the area. They are a fast-growing tree that provides wonderful shade. But they also produce a ton of seeds in the spring and are weak-wooded with limbs that easily break from snow, ice or wind.
Preliminary research shows the insect may not have the ability to take out a mature tree. How and if you choose to control the insect is up to you. Personally, I wouldn't mind a couple of juvenile seedlings to be used as flea weevil meals for a couple of years.
In an attempt to suppress the damage inflicted on the tree, make sure they are not stressed (give them plenty of water).
There is an over-the-counter insecticide with the active ingredient imidacloprid, which is applied as a soil drench. The challenge with this approach is that for the larger trees, the cost of the product becomes prohibitive. Apply the product in the fall after leaf drop to control early spring feeding of adult elm flea weevils.
The city of Durango is also well-aware of the problem and will be taking some preventive measures for the city-maintained trees.