Cankerworm outbreak in Weber And Morgan counties

In case you were not already aware there is a serious outbreak of the larval form of a moth which attacks hardwood trees (think native benchland maples). I believed it to be Alsophila pometaria and sent samples to the UDAF for confirmation.


Cankerworm larvae completely defoliate maples and other trees . This creates an esthetic issue for everyone and a commercial issue for high value props and recreational / tourism properties . It is also possible it will cause serious fire hazards .

Some trees will refill after the weeks-long attack , but it is yet to be proven if this will occur in severe drought conditions .

The major outbreak areas are around Huntsville benchland areas and across Trappers loop.

Licensed commercial applicators do have tools and appropriate pesticides to treat the larva , it is not recommended that DIY types do any spraying due to personal danger and risk to pollinators.

In the weeks ahead the larva will lower themselves to ground level and dig into the soil to pupate. They will be the moths of egg laying females for next year

There is one generation per year, the larval stage is the best time for control, though we have not seen them in urban areas yet, they will surely come.

We have residential and commercial Equipment at Harmon and Sons if someone is looking for treatment .

810 771 2000

Jerry Auble ISA Certified Arborist

Utah 4566A

Utah Licensed Commercial Pesticide Applicator


Feel free to contact me with questions