Apple Maggot trapout in Vermont- a grower's experience.

Jim Gallot, Manager, West Meadows Farm, New Haven, VT
February 1996

West Meadows Farm is a 30 acre apple orchard located in the
Champlain Valley of Vermont. Five of these acres have been
managed using Apple Maggot (AMF) trapout for the last 4 seasons,
and all 30 have been under AMF trapout for the 1994 and 1995
seasons
. There are two trapout methods that have been developed,
the red sticky spheres developed at the University of
Massachusetts and the Ladd Traps, developed at the University of
Vermont. Both require an odor attractant lure with each trap to
be effective.

The red sticky spheres are hung every 15 feet around the
perimeter of the orchard. This was the method I started with on
the first 5 acres. It worked, but required over 200 traps for
the 5 acres, and expanding to include the entire orchard using
red spheres was impractical because of the trap cleaning and
maintainence involved.

The Ladd trap is a red plastic sphere superimposed on (actually,
bisected by) a bright yellow plastic rectangle. In side by side
tests here in the orchard, it has been much more effective than
the red spheres in attracting AMF. I can effectively trap out
the entire 30 acres with 80 Ladd traps, compared with the
hundreds that would have been needed with red spheres.

Table 1 - Comparison of Ladd traps and red plastic spheres, odor
baited with AMF vials from Pest Management Supply (now part
of Gempler's). South block, West Meadows Farm, New Haven
VT. Ten traps each type, 1993.

Total AMF captures, 7/13-9/16/93
Trap Average High Low 2nd lowest
Ladd50.7 91 7 29
Red sphere 12.6 28 2 4



This is the trap-out strategy using Ladd traps as suggested by
Ladd Research Industries, as distributed with the Ladd Trap Kit:


begin quote...

1) This Strategy functions best in orchards that received insect
pest management during the previous growing season.

2) The location of all wild and unsprayed apple and hawthorn
within 300 to 400 yards of the orchard perimeter must be located
and identified, and one Ladd trap hung in each tree so
identified.

3) A Ladd trap should be hung every 100 ft. in the outside row
of trees (within the orchard) facing the direction of the wild
apple or hawthorn, if any.

4) Using one trap per acre, hang the required number evenly
through the orchard, hanging all traps about shoulder high, on
the south quadrant of the tree about 18 inches into the canopy.
Obstructing foliage should be removed in the vicinity of the trap
to give a clear view.

5) Place traps prior to the emergence of the first flies.

6) Clean traps of extraneous material, as necessary, by scraping
to insure visual acuity. Cleaning will probably be necessary one
to three times during the course of the season.

7) Place septum with the apple volatile on top of the red sphere
and resting against the yellow panel, after the adhesive is
applied. Replace septum every two or three weeks during the
course of the season.

8) Adhesive is best applied by hand using disposable plastic
gloves, and making sure that the adhesive is warm before
application.

REMEMBER: If wild and unsprayed apple trees and wild hawthorn
are not properly located and identified, and traps are not hung
in them, the number of migrant flies moving into the orchard will
overwhelm the traps (at one per acre) resulting in probable
maggot damage, and totally unsatisfactory results.

...end quote


In true Yankee fashion, I don't follow this precisely. I differ
by:

a) I use Brushable Tangletrap rather than the regular Tangletrap
recommended by both Ladd Industries (and UVM) and by U Mass. It
isn't as thick, thus is easier to handle, and as long as you gob
it on pretty thickly, it will trap the AMF fine in my experience.
Don't be skimpy with it! I have on occaision found bird feathers
on the trap, but the birds themselves can get loose. The same is
not always true of the regular Tangletrap, as I have heard
second-hand.

What is Tangletrap? It is like the stuff on flypaper. Anything
that makes it easier to use is a definite benefit! There is no
way that I know of to not get it on you as you work (forget the
plastic gloves). Vegetable oil and soap works for me to remove
it from my hands etc.

b) I do not distribute the traps evenly throughout the orchard,
I do the perimeter and down the central access road. In this
aspect, what I do is a hybrid of the UMass and UVM models. Copy
this at your own risk.

c) Traps are put closer than 100 feet apart at 'hot spots' for
AMF captures. The more AMF caught, the more traps, and the
closer together they should be.

d) I hang the traps on the side of the tree away from the
orchard, not within the orchard (see #3 above), so that it is
immediately visible to approaching AMF. Don't ask me why, I just
do.

e) I use the Butyl Hexanoate vial lures developed at UMass and
available through Gempler's. The odor will permeate through the
walls of the polyethylene vial when it is sealed, but I have
found that under dusty conditions the vial seals up with dirt. I
drill a very small hole in the top of the vial to provide ample
release of odor. Another method is to 'crack' the cap of the
vial open a little so it is not sealed completely. I have not
tried that method, but it is probably the better of the two. One
vial generally lasts the whole season.

f) This isn't a difference from the protocol, but I do want to
make the comment. I remove wild apple trees where I can find
them, and the traps will aid you greatly in finding them. At
least for the first few years do detailed trap capture counts.
The 'hot spots' will almost invariably point you to a wild tree
you didn't know was there. It may be hidden in among other
trees, it may be right there, but only blooming every few years
because it is intertwined with other trees, but I'll bet dollars
to donuts it's there somewhere. They're not as easy to find as
you might think.

The wild trees may not be on your property, so you may not be
able to cut them down. One other Vermont grower who uses Ladd
traps gets around this by massing traps as close to the source
(abandoned apple trees on the neighbors property) as possible.
The 'every 100 feet' is just a guideline. The traps should be as
close together as needed to intercept incoming AMF. In some
circumstances and places in the orchard, that could conceivably
be every 10-15 feet.----



I consider the use of AMF trapout to be the backbone of my pest
control strategies. Codling moth is present in the orchard, and
is kept under control by using mating disruption. Leafrollers
and Tufted Apple Budmoth are kept in line with summer B.t.
applications. There are no broad-spectrum insecticides applied
after mid-June. This allows ample natural predators and
parasites to develop in the orchard.

Using Ladd traps has reduced the number of traps required to a
managable level. The Tangletrap is messy to work with, but I
find it, again, managable. I will admit cleaning traps is not my
favorite job! For those who simply cannot stand to have their
hands sticky, UMass is currently working on insecticide-coated
spheres which will kill the fly when it lands on the sphere
rather than trap it. The exact technique has not been fully
worked out, at least as far as I have heard, but it is coming in
the probably not too distant future.

This is a basic outline of what I do for AMF trapout. You will
notice that it is not exactly like either the UMass or the UVM
method. What is required in your orchard is probably not exactly
like what I do, either. Be sure to record trap captures to
detect 'hot spots', and use unbaited spheres to monitor what is
going on within the orchard. If the monitoring spheres indicate
a problem, application of an insecticide is probably a good idea
(as my son would say, Duh!). Identify where the AMF are coming
in, and tighten the trapping activity there. Don't discount that
there may be a breeding population within the orchard if previous
control has been lax. Take nothing for granted. Stay alert.
Good luck.----



Ladd Traps available through:

Ladd Research Industries, Inc.
P.O. Box 1005
Burlington, VT 05402
Phone (802) 878-6711
Fax (802) 878-8074

There has been (and probably still is) a minimum $20 order. The
1995 prices were $12.95 for the Apple Maggot Fly Trap Kit (trap,
info, tangletrap, their lures, plastic gloves), $2.95/ea for the
red sphere, $1.95/ea for the yellow rectangle (one each required,
assembly is easy). Prices may have changed. I suggest you buy
one kit in order to get the info, buy the rest as individual
traps. Remember, you will need to buy the Tangletrap and lures
to go with the plain traps.