Asked May 18, 2016, 11:17 AM EDT
Weld County Colorado
Never heard of that, but a VERY common borer on ash trees is the Lilac-Ash borer.
Maybe the representative meant Lilac-ash borer. More info:
Thanks Robert. She may have said Lilac and I mistook for lavender (thinking of colors – emerald vs. lavender). I’ll check the link. She did point out some very distinct bore holes. I’m thinking of just taking out that ash and replacing it with something else. Do you have any recommendations? It's a street lawn tree, so it fits the profile of one that is primarily susceptible to the LAB. I also have a purple ash I planted farther away from the street next to our driveway that appears to be fairly healthy.
Drought-stressed ash trees, those with a limited rooting area, or other stresses make that ash more prone to LAB injury. Autumn Purple ash is very susceptible, especially when stressed in any way. So be sure to provide it adequate water during the growing season AND during dry warm snowless periods in winter months
The borer exit holes she showed you are almost certainly the handiwork of LAB.
Preventive trunk sprays of the insecticide carbaryl (Sevin and other trade names) or permethrin (several trade names) should be applied mid-April to mid-May.
If you decide to replace the ash tree with another type of tree, consider these; note that every tree has some potential pest problems and disavantages.
Japanese tree lilac
Hackberry (many insect galls)
Greenspire Linden (may leaf-scorch in limited rooting areas)
Norway maple - many named varieties
Thank you Robert. You've been a "tree"-mendous help. (sorry, had to do it....). Have a great day!!