A Codling Moth Story … December 2010

by Frank @ Father Earth Organic Farm

I have read a lot of info about Codling Moth and have learned a lot from Forest Peterson, Martha young, and other BCG members.  I have been living at my home in Lafayette for 8 years now and finally got tired of bad apples on the two old trees by the side of the house.  The house was built in 1966, and I assume the apple trees were planted about the same time.  Although they have produced apples every year since I have lived here (some years more apples than others), they were 100% inedible.

Here is an account of my personal experience.  Three years ago I began learning about ways to increase my odds of being able to bite into an apple off my trees without biting into a worm. There is a lot to consider when dealing with any pest in your environment.  There are so many variables.  Even within a 10 mile radius of where I live, there must be at least 10 to 20 different microclimates that may require different control methods for the same pest.  On any given day, the wind, rain, temperature, clouds, and sun could very possibly be different for my garden than yours.  So, with that in mind, you may have to adjust whatever control methods you use to work with some of these variables.

The first thing I tried three years ago was the molasses. Being on a limited budget, this method seemed to be the least expensive.  I tried two kinds, a granular and a liquid, both mixed in a water solution.  The more concentrated the solution of molasses to water, the better the results.  By results, I mean that the jars, pots, jugs hanging in trees, or containers with the liquid molasses mix, caught the most codling moths.  So over a two week period from the last week of May thru the 1st week in June, I may have caught about 150 to 200 moths.  This may seem like a lot of moths, but by this time in the season, the apples had set, and upon inspecting the trees, I could see at least one – head of a pin sized clear jelly spot – on every apple I looked at.  So, yes, the molasses helped to keep a hundred or so moths from laying their eggs, but what about the other … thousand. or more?  My analysis of this season takes me back to the variables… and timing.  Maybe I missed the beginning of the moth cycle by a week or two. Either too soon, or too late.  That could have made a difference.  And missing the cycle could have been caused by the elements, too cool, too wet, and too dry, for the moth to lay eggs at a given time.  And so, another frustrating year of bad apples.

Back to the drawing board.  Wish it was that easy.  More research, and talking to Forest Peterson, leads me to the Kaolin Clay product.  Green Cypress kaolin Clay Crop Spray is from Peaceful Valley. You can get the same clay product under the name of “Surround” from Fedco, and Raintree nursery.  I’m sure there are other sources, but seeing that I already use these companies for other products, I didn’t see a need to research further.  A 50# bag of clay is $40 at Peaceful Valley.  It is twice as much or more at the other two places.  Then of course there is the shopping charge.

But wait a minute!!  Just because you have the clay, doesn’t mean your problems are solved.  PV doesn’t mention anything about applying the clay for the coddling moth.  Raintree says to apply the spray when the fruit is small.  Well we all have a different idea of what is small.  Is small, pea size, marble size, jawbreaker size, or golf ball size?  In my experience, by the time you see the form of an apple, it is usually too late and the worm has already entered the apple.  Fedco says to spray just before petal drop, or blossom drop.  And just what does “just before” mean?  Does it mean an hour before, two days before, or a week before? Who knows!! I haven’t seen any neon signs flashing in the trees saying “almost time for petal drop, get ready to apply spray”.  So I took an educated, or uneducated” guess to spray the trees when I physically saw the first petals fall from the tree.

So, on Tuesday May 19, 2009, I sprayed the apple trees.  Seems easy huh?  Although the petals began to drop a week earlier, I had to wait until the 19th for the conditions to be right.  Spring winds are always around and so you can’t spray during that time.  Then if it’s going to rain, it will wash off the clay film and you have to spray again.  At this point after spraying, all you can do is hope that you beat the coddling moth laying activity.  If the weather provided the right conditions, the moth could have laid her eggs three week prior to the tree being in full bloom.  In that case, the eggs could have hatched and the worm is now feeding on the leaves, waiting for the apple to form.  Even thought the worm will not eat the sprayed leaf, it is nearly impossible to spray every leaf.  So it is my suggestion to spray again as soon as you can tell that the apple is forming.  This should be when 80 to 90% of the petals have fallen, and the red/green apple is about the size of a pea.

The second cycle of laying came and I did not spray due to the weather.  Too windy two days, and rain three out of five days.  I figured it was too late to stop the damage, and so I didn’t spray.  At this time, the apples were almost golf ball size and looked pretty good as compared to the apples of the year before.  But by late July, and early August, when the tree begins to drop apples, there were quite a few apples with several holes in them.  I conclude that the weather must have provided the right conditions to allow a possible third laying cycle.  So, needless to say, the apples weren’t very good this year, but somewhat better than the year before.  Things will be better next year.

Fast forward to September and October, 2010.  The apples this year were much, much, much better than they have been the past 8 years combined.  Here is what I did to create this success.  Mother’s day came on May 9th this year and most of the apple trees were in full bloom by then.  I wanted to spray the clay the week before, but weather wouldn’t permit it.  On May 10th, it was foggy and cool at 6:00 in the morning and I thought it would be a good time to spray.  There was hardly any wind, and the bees were not out yet…. Probably because it was foggy.  I wanted to spray the day before, but by the time the winds died down about 9:00, the bees were all over the apple tree blossoms.  I don’t know what effect the clay film would have on the bees … or the honey, but didn’t want to take a chance.  I started spraying about 6:15 and finished all the trees by 7:45.

It turned cold on Tuesday the 11th and Wednesday the 12th, I woke up to 3” of snow.  I thought the snow might hurt all the flowering fruit trees, but the snow was all melted by Wednesday night, and the trees looked pretty good.  So with this added variable, snow, maybe that killed a lot of worms and moths, and maybe that is why the apples were much, much better this year.  Who knows??  One book I read said that the moth cycle was “about” 6 -7 weeks.  So I calculated that I would need to spray around the end of June or the first of July.  On June 23rd, the golf ball size apples looked great.  At least 80% of the apples I looked at were wormless. I delayed my spraying because of weather, until July 1st.  Some time between June 23rd and July 1st, there must have been a hatch of eggs that were laid a week or so earlier.  By July 4th, I noticed more worm holes in more apples.  So next year, I will make a note to spray “about” the 5th week, from the time of the apples set… or forming.

I just learned this year about a possible third cycle during the year… depending on the weather and climate conditions that would allow the moth to reproduce again.  I didn’t spray a third time this year.  Truth is, with so many other things to do on the farm, I just got tired of trying to schedule another spraying in between the unpredictable weather/climate conditions.

My plan for next year is to “fine tune” whatever I did this year and try to be more aware of what nature is doing in the spring especially.  During the winter, the Pupae of the moth are in hibernation somewhere.  These pupae could be in the ground, in dried apples lying under the apple tree, in the crevice of tree branches and bark, or any other place where they can make a cocoon and hide.  When the weather warms in the spring, the moth emerges and begins to lay eggs.  The fruit (apple) trees also begin to bud when the weather warms.  This would seem like a good time to spray.  The tree is usually in full bloom within 2 to 3 weeks after the buds open.  I had good results spraying at full bloom last year, and so will do the same thing again.  Then once the petals drop, I will schedule to spray again in 5 weeks, and then again 5 weeks after that.  The larvae that do make it into an apple will be coming out after about 3 weeks to enter into the hibernating larvae and pupae stage.  So here are some more things that can be done pretty easily.

The apple season is a peak time to work on your organic strategies for codling moth. Inspect the trees every 10 days, collect any fruit you find with small holes and destroy it by immersing it in water for several days. Alternatively place it in a sealed, black plastic bag in the sun, and then try feeding it to poultry.

Remove loose bark and leaf debris from the crotch of the tree, to reduce hiding places for cocoons. Corrugated cardboard bands can be placed around trunks and limbs to trap caterpillars looking for a place to pupate. Inspect every 3 weeks and destroy any cocooned caterpillars. The most important trapping time is winter and spring but for effective control inspect the bands all year round.

A horticultural glue such as Trappit Barrier Glue or Tanglefoot Glue around the trunk of the tree will prevent the movement of some of the female moths from the ground into the tree, as they tend to crawl and flutter up the branches. It should be in place from the first moth sighting until mid-winter. Using the glue below the corrugated cardboard bands will also help to force the larvae looking for a pupation site into the cardboard bands, as it will make it more difficult for them to reach the ground.

The first bullet above talks about collecting and destroying any fruit you find with holes, both on the tree AND on the ground.  I collected three wheelbarrow loads of apples that had fallen from the trees, but I failed to destroy them as recommended above.  And I also failed to collect apples with holes from the trees.  Right now, those apples that I collected are in my compost.  So there could be hundreds or thousands of hibernating pupae waiting to hatch in the spring as moths.  My compost is now a possible breeding ground for this moth.  Sometime during the winter, and before April, I will clean up the apples in my compost and destroy them as recommended above.  I also raked up all the apples that had fallen under all the trees.  That should help a lot.

I baked several pies using the apples off my trees.  I used the same recipe for all the pies.  The red delicious apples were firmer than the others and not as sweet.  The Macintosh was a bit sweeter, but not as firm as the red delicious.  The golden delicious were softer than the previous two pies and sweeter also.  The Jonagold (cross between a Jonathan and a golden delicious) was the sweetest and softest of all.

I wanted to make one last note about the codling moth AND her accomplice.  Yes, the codling moth is not working alone.  The EARWIG played a huge part in destroying some apples in my orchard this year.  There were a lot more earwigs on the farm this year than I have ever seen here in eight years.  They were everywhere!!!  They were in my apricots (at least 50% of them), the peaches (20 – 30%), plums (20 – 30%), and in the apples.  Sometime in late June thru August, the apple trees begin to drop apples.  Most of these apples are infested with worms.  I just happened to pick a couple of apples with worm holes off the tree and cut them open to see if I could see the worm (larvae).  I was surprised to see earwigs in them.  I cut open a couple dozen more apples off two trees, and all had earwigs in them.  There were no worms.  So here is a puzzle.  The worms could have left to find a place to hibernate and pupate.  There was worm excrement on these apples, so I know the worm was there.  Could the earwig have eaten the worm?  Did the earwig enter the apple before or after the worm entered?  I think the earwigs entered sometime after the worm entered.  When I checked the apples a month before, when they were golf ball size, there were no earwig size holes in them.  Earwigs are omnivores and so it is highly possible that they ate some of the larvae inside the apple.

The peaches and apricots did not have worm holes, so I can assume the earwigs were not after the larvae.  They just wanted to be a nuisance.  Although earwigs have wings, they do not use them very well for getting from place to place.  They transport themselves mostly by crawling.  So next year, I will be putting a band of Tanglefoot or trappit barrier around the trunk of all my fruit trees as soon as they begin to bud.  That should eliminate the destruction of a lot of fruit.

One more thing that may or may not be related to the codling moth.  My Yellow Egg plum tree has been producing for 4 years now.  I have never had worms in them.  This year there were worms in 90% of the plums on that tree.  I sprayed the kaolin clay on all the surrounding apple trees, but not on the peach and plum trees that were nearby.  Just a thought, but maybe because the codling moth couldn’t lay their eggs on the apple trees, they decided to lay their eggs on the plum tree instead. Everything gets sprayed next year.

For the 2011 growing season, I wish you all the best in this New Year to come.  Hope some of this info is helpful to you.

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