Red Maple borer attack
A recent letter from Peter has been answered by Stephen Frank at Tree Logic and so we include here as advise to those with similar problems.
Hi
My name is Peter I have a problem with my maple tree in the back yard.
Can you help me with a grub that seems to be eating the crotches and trunk of this Acer rubrums.
It is a young tree.
If I send some photos can you please give me a consultation? Possibly a way to save the tree from getting worse as we love the tree I am happy to pay you for your time
Regards
Peter
Hello Peter,
Indeed your Red Maple has a problem, and to be honest one that can not be solved by any arboricultural treatment I am aware of.
Judging from the photo accompanying your email, the pest has been present for some time and extent of damage is too much. It would appear that ~50% of the circumference of the stem has been affected.
Control of borer in trees is very difficult. Most borers attack trees weakened by drought, mechanical injury, recent transplants, poor soils or root systems. The most important prevention of borers is keeping trees healthy through proper management (primarily watering, which again can be difficult under current drought conditions). The most common way to control borers, in addition to proper tree maintenance, is chemical control. However, borers live inside trees, and treating them with insecticides is difficult if not impossible, and it comes down to timing of treatment. The best time to control borers is when adult are laying eggs on or under bark, which is difficult to monitor in a domestic situation. Pheromone traps, available for some borer species, help determine if adults are present. Trunk sprays can be effective when borers are in the early larvae stage before they enter the tree. I reiterate that the extent of damage with your tree suggests that the tree is past chemical treatment. I have heard people using a fine wire to poke into the tunnels created by the borers in the hope of skewing one.
I would suggest you remove the tree (as distasteful as it sounds) and replace it with a new one. Properly plant species that are well adapted to your location and provide them with proper care. Avoid pruning from spring through summer when adults are active. Protect trees from injury. Remove and dispose of dying limbs and dead trees. Do not pile fresh-cut wood near trees.
I hope this helps.
Sincerely,
Stephen Frank

