Can You Control Emerald Ash Borer With Neem

Ash trees are currently in the “problem” stage with a new pest that’s sweeping across North America – the Emerald Ash Borer. Here’s a bit of work researchers in Ontario have done with this pest and neem oil.

Small trees (diameter under one inch) were planted in an area where the mature trees destroyed by the borer had been disposed of. So a good supply of borers were available to infect the trees.

Azidarachtin – a derivative of Neem tree seeds – was injected into the trees in varying concentrations. With the higher application rates, all larvae were killed. But no adults were hurt. (rather a good news – bad news kind of thing)

Now – researchers are working on larger trees and trying to establish the level of chemical necessary to stop the larval stage. It would appear there’s a solution on the horizon but it’s likely going to take a few years.

Note that simply spraying the trees doesn’t do anything because the adults don’t seem bothered by the chemical and the larvae are protected within the tree – the chemical had to be injected to be effective.

This means when you hear through the grapevine that neem will kill off emerald ash borers – you know the truth.

Reference: Nicole McKenzie (Dept. of Environmental Biology, University of Guelph, Guelph, Ontario, CANADA N1G 2W1), Blair Iielson, Dean Thompson, Gard Otis, John McFarlane, Tere- sa Buscarini, and Joe Meating, “Azadirachtin: An Effective Sys- temic Insecticide for Control of Agrilus planipennis (Coleoptera: Buprestidae,” Journal of Economic Entomology 103(3), June 2010, 708-717. (Entomological Society of America, 10001 Derekwood Ln., Lanham, MD 20706-4876.)