Question
I am running into a problem with bores on honey locusts. what understand is the locusts borer hits black locust. the damge from this insect is almost to late.Are the round headed or flatheaded bores. Can zylam kill them and whats the rate per PDH.I'm not understanding the rates per 100 g of water. I want to do soil injections. If you can help me I would very thankfull

Answer
My first thought is honeylocust borer.

The various honeylocust borers are metallic or longhorned beetles that spend larval stages tunneling under the bark. This injury can contribute to honeylocust decline, but borer problems are rarely the fundamental cause of the decline. The most common species in honeylocust are thought to emerge and lay eggs during June.

Honeylocust borers can attack and develop successfully only in trees already stressed due to drought, root pruning, disease or other causes. Most borer activity occurs in areas of existing cankers. External evidence of a honeylocust borer infestation include "weeping" at wounds and the small circular to oval exit holes made by the adult beetles as they emerge from the trunk.

Proper watering, tree care and, in particular, wound prevention are the most important techniques for reducing problems with honeylocust borers. Usually, this is sufficient.

Supplemental insecticidal controls should consist of maintaining a protectant insecticide on the tree trunk during the egg-laying and egg-hatch period in early summer. Permethrin (Astro) is used for control of related borers attacking other shade trees. Alternately, soil drench applications of imidacloprid can be effective if applied in spring to trees not already damaged badly by borers.

There is a newer insecticide called Merit that works well on borers. Onyx is another insecticide for bark beetle and borers. It is mixed with water and sprayed on the trunk. Borers attach because the tree is weaken and if the attack is al the way around the trunk the tree maybe already dead and the spray will kill the borer but have no effect on keeping the tree alive. I would think the stress of the drought weakened the trees and the borers infested the trunks.

The Zylam is also an alternative insecticide. Here is the recommendation for its use as a soil applied or trunk spray.  http://www.gordonsprofessional.com/pdfs/ZylamLiquidEmeraldAshBorer-ControlSellSh

I would also fertilize with 10-10-10 fertilizer at the rate of 1 lb. per inch of trunk diameter scattered around the tree and watered in good, Apply just before a rain storm and you will not need to fertilize,