Many landowners have discovered the benefits of systemic chemical treatments when it comes to Hemlock Wooly Adelgid (HWA) infestations. Imidacloprid and Dinotefuran are the two most common insecticides that are used to manage adelgid outbreaks throughout the Hemlock range. In most cases, Imidacloprid is applied to trees containing a light to medium infestation, while Dinotefuran is reserved for heavily infested trees. Trees systemically treated with Imidacloprid typically begin to show results anywhere between six and twelve months. Imidacloprid typically has a residual effect for five to seven years, and therefore, re-treatment is recommended for every five years. Dinotefuran results are typically seen much quicker, with results being evident anywhere from three to eight weeks after treatment, but requires an earlier re-treatment to maintain resistance to the HWA.

A variety of application methods can be used to deliver these systemic treatments. To determine the proper method, a number of factors must be taken into account including, but not limited to: infestation level, tree diameter, and location. The most common application method utilized by TerraMedics is soil injection due its affordability, portability, and good track record for results. Basal spray is another common method utilized by professionals for the treatment of HWA. TerraMedics will evaluate each individual circumstance in order to develop a plan that makes the most sense for each landowner.