Wednesday, September 1, 2010

Imidacloprid drench for insect control.

A simple method of insect control consists of drenching the soil around a tree with a product containing imidacloprid.

The first step is to read the label.

This product points out the need to measure the circumference of the tree 4 1/2 feet above the ground.  This hackberry tree has a circumference of 29 inches.

The second step is to apply the proper amount of product 

The directions say to add one ounce of the product per inch of tree turnk circumference to a gallon of water and use this to drench the soil around the base of the tree. 

I purchased this 40 ounce container for $30. Thus each ounce of product costs 75 cents. Treating this hackberry costs $21.75.  This treatment will provide excellent control of aphids, borers*, and gall-making insects in this tree for a full year, possibly longer. This application will also prevent lawn grubs in the area where I applied the drench around the base of the tree.

While I don't like to apply a nitrogen fertilizer to trees in the fall, many pesticides contain nitrogen to help increase the uptake of the chemical. This small amount of nitrogen (2%) in this product should not be a problem with trees or shrubs even when applied in the fall.

My next task is to spray out the grass around the base of the tree to help protect it from lawn mower and string weeder damage.

I have used the granular form of turf imidiacloprid insecticide on my lawn for grub control.  Since this treatment was made close to lilacs, virginia creeper and other woody plants, a secondary advantage of this lawn treatment was the control of insects (except Leps *) in these plants as well as in the lawn.

Be sure to read and follow the label directions.  If the product does not list vegetables or fruits,  do not use the product on those plants.

* Leps = Lepidoptera species of insects. Imidiacloprid is not an effective control of the larvae of moths or butterflies that bore into the trunk or feed on the leaves.