Hi All,
We’ve been gone for the holiday and I’ve just
noted all the questions about a “righteous borer tool.” Hopefully
what follows will answer all the questions. I am always amazed at what images simple
words can conjure up (and, hopefully, thus learn how to be that much clearer in
my writing!).
- My tool of choice to now pry
out the borer grub is a 3/8” spade bit, as sold in the tool section
of any hardware store. Irwin and DeWalt are two drill bit brands. This
bit is used solely by itself – no drill or router is involved. I am
not “drilling” out the grub in any fashion whatsoever. The
spade bit is more akin to a pocket knife, only with it’s narrow
drill point, that much more effective in getting down to the bottom of the
meandering grub damage and actually skewering the pest. A stiff wire is
useful in this regard as well.
- What’s really, really
critical to understand with
this insect is how important it is to successfully get the developing grub
in that first fall season or early the next spring. The eggs are laid in
June, July, and August. One female may oviposit as many as seven eggs at
once. Sometimes another female may come by two months later and add one or
two more eggs. A vigorous growing tree may crush some of these; birds that
poke into the bark at the base of the tree may find a few. All summer long
I use the blunt edge of my hand pruner to smush any fresh egg slits. But
come the fall months I get serious, as in being systematic in going down
rows to every tree AND as is being thorough in opening up the damage.
- People naturally are concerned
about damaging the young tree. Truth is the borer grub has totally
destroyed the “cambium connection” wherever it has been feeding.
Thus I always feel free to open up the damaged area and follow every
meandering turn to its end. Again, I want to stress that I am doing this
early along in the damage curve (so to speak) when the 1/8 to 1/2 inch
grub has done minimal damage compared to what’s to come. The sooner
you get it, the less damage done. Cutting away the dead bark with a pocket
knife or stiff poking tool like a spade bit only reveals the totality of
destruction AND where the healing callus will develop along the edges of
the damage. The tree itself closes off the damaged area (with or
without our probing) and ideally rebuilds the cambium connection with its
growth rings to come.
- Orange frass coming out of the
bark is one visual clue but not the only one. Blackened bark, sometimes
sunken inward, sometimes not, just as often reveals a problem as the frass.
Some borers are small enough to “contain” their frass early on
within the damage area, thus you will see no frass. These are the ones
more easily missed. All egg slits and any dubious places on the bark at or
near the soil line should be poked to see if such lead onward. Do pull
back the soil for an inch or two downward when doing this check. (My trees
have peastone mulch at the base, which helps in this regard.)
- You absolutely need to see the
guts of this creature to know you’ve done a righteous job. Some
borers go downward for awhile but then go back to the upper edge of the
damage. Some dip around a root and hide on the other side. Some “merge”
into a younger grub’s tunnel, leaving you satisfied with a victory
that still leaves the younger grub lingering behind. It really helps me to
see past damage opened-up -- from entry point to the bitter end – in
order to be sure.
- The adult round-headed apple
tree borer is a tan to whitish beetle, with longitudinal stripes, about an
inch long if you don’t count the antennae. Forget that post that
said the RHAB is six inches long . . . such a creature would take us out
as well . . . ready guys, here he comes
. . . argghhh!
- Numerous tree species can fall
victim to the borer. Wild apples, hawthorn, serviceberry, and a wetlands
maple (don’t know the exact species name) seem to contribute to the
extreme pressures at my site. I remove all unmanaged species on occasion.
Migration is limited to a few hundred yards a year, thus being surrounded
by cornfields is probably a big help. If you get good at “borer duty”
you should find a decline in borer pressure over the years.
- The reason I like the spade bit
is that now I have a tool that combines the attributes of a pocket knife
with a stiff wire. What I’m describing is kind of like dental work:
open up the cavity completely, find the problem, and then let the healing
begin. Don’t leave gobs of frass in place to only confuse you on the
next search.
- The idea of an organic syringe
is really only a backup to get those grubs that escaped you in their first
year. That’s when damage goes deeper and the surface area loss of
cambium often becomes irreversible. Phil Norris in Maine is the one who suggested a long
piano wire for such cases. Now you’re not preventing damage as much
as stopping pupation and thus another round of egg laying when the grub
becomes an adult.
Hope this helps.
Michael Phillips
Lost Nation Orchard
Heartsong Farm Healing
Herbs
859 Lost Nation Road
Groveton, NH 03582
603-636-2286
www.HerbsAndApples.com
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