Imidacloprid, Insecticides and Safety

Q. I don't like what I'm reading about Imidacloprid (frequently found in borer control insecticides) and wanted to know if there is a better insecticide that won't harm bees.

Bayers Tree and Shrub Insect Control insecticide is one of many insecticides approved by the USEPA for killing some borers, like Emerald Ash Borer (not currently found in Nevada). 

A. You are talking about an ingredient (tiny letters on the label under active ingredients) found in several different products rather than an actual product name (big letters) found on the label. The actual or product name might be “Merit” for commercial applicators and “Bayer Tree and Shrub Spray” for homeowners but also many others

Some Countries Banned It

As a "class" of insecticides, the neonicotinoids are the most used group of manufactured insecticides in the world. Insecticides containing imidcloprid have been banned for use in some countries due to accumulated evidence. That particular ingredient is still approved for use in the United States but has faced a lot of environmental problems and may be eliminated in the future. It has been implicated in the death of some pollinators like honeybees when visiting the pollen contained in open flowers.

How to Apply it Safely

The label information for these types of products gives you a clue about how to apply it properly. If you must use this product, apply it to plants after they have finished flowering. This helps prevent the transmission of this ingredient to pollinators.

Alternatives

At this particular time I don’t know of any insecticide available or permitted for use that has the same potential for controlling borers as imidacloprid. Its major advantage is also, potentially, its disadvantage; it is a long-lived systemic insecticide that can potentially be harbored in flowers, fruit produced and plant parts for up to 12 months. The only other option I know that can work is the digging of these problem insects from infested trees as they are seen.

 

Borers can be removed from an infested limb with a sharp, sanitized knife.