June 3, 2016

Codling Moth Season Has Begun!

Everyone likes to eat apples, including over 70 insects and a long list of fungi and bacteria.  To produce good tasting, good looking fruit, we have to control those pests.  Of all the flying pests, codling moth is probably the pest needing to be controlled the most.  Codling moth is responsible for the proverbial worm in the apple, so to speak!  As we hit 250 Degree Days in this pest's flight cycle, lets see how we might control it. 
Everyone likes to eat apples, including over 70 insects and a long list of fungi and bacteria. To produce good looking tasty apples we have to control those pests. - See more at: http://www.royaloakfarmorchard.com/workshop.htm#sthash.ySYdHMZ9.dpuf
Everyone likes to eat apples, including over 70 insects and a long list of fungi and bacteria. To produce good looking tasty apples we have to control those pests. - See more at: http://www.royaloakfarmorchard.com/workshop.htm#sthash.ySYdHMZ9.dpuf

Codling moth is a small moth whose caterpillars bore into the fruits of apple and pear trees during mid- to late-summer.  Codling moth is the cause of what is often referred to as "the proverbial worm in the apple". The caterpillars of this insect can damage a high proportion of the fruits on apple trees in gardens in a small amount of time.

Codling Moth Larvae
Newly-hatched larvae (caterpillars) chew through the fruit skin and bore their way to the core. The presence in fruit of one or more holes plugged with frass (excrement) is characteristic of attack by codling moth. The larvae enter the fruit through the sides, stem end, or calyx end, and a syrupy substance may exude from the holes as the fruit matures. Shallow entries called "stings" result when larvae penetrate a short distance and then die from insecticide poisoning or natural causes.

The eggs, larvae and pupae of codling moth each have specific physiological time requirements to complete development before they transform to the next stage. Temperature also affects the flight, mating and egg laying activities of the adults. Although the minimum threshold for emergence of moths is 50 degrees Fahrenheit, male moths do not fly until temperatures exceed 55.4 degrees F and codling moths do not mate until temperatures exceed 60.8 degrees F.
To determine when flight begins for codling moth, commercial growers make use of pheromone traps.  Once moths have been trapped for  two consecutive days in a row, a biofix is set  that initiates the beginning of growing-degree-day calculations.  We know that at 100 degree days after the biofix date codling moths begin to lay eggs and those eggs begin to hatch at 250 degree days after biofix.  It is this information that aids in the timing of necessary sprays for codling moth so they do not damage fruit.  Growers wishing to time sprays based on egg development and hatch should make an application of an insecticide at 250 DD (base 50 degrees F) after the first sustained capture of males in the sex pheromone traps.  Here is a Detailed Growing Degree Day Model for Codling Moth. 
For the home orchardist who does not have the benefit of a weather station or other means to calculate degree days, a simple tree growth stage time table can be followed.  Codling moths usually start flying at bloom time. Eggs laid by these moths begin to hatch about two weeks after petal fall, depending on the weather. You can apply the first codling moth spray at this time to prevent larvae from entering the fruit. Because insecticide residues last 7 to 10 days and moths are continuously present throughout the summer, apply a spray every 7 to 10 days to prevent later broods of codling moth larvae from entering apple and pear fruits. Always follow the label directions of any spray you may use.

Several insecticides can be used for codling moth control including acetmaprid and/or spinosad.  Acetamiprid is a soft, conventional control and is available as  Ortho Flower, Fruit & Vegetable Insect Killer.  This is a ready to use product that contains .006% acetamiprid, a synthetic organic compound of the family of chemicals that acts as neonicotinoid insecticides. Acetamiprid is a contact insecticide for sucking-type insects and can be applied as a foliar spray or a soil treatment. Acetamiprid acts on a broad spectrum of insects, including aphids, thrips, plum curculio, apple maggot and Lepidoptera, especially codling moth.  When sprayed in the evening at sunset, it will not harm bees or other beneficial insects.  Be sure to follow all label directions on the bottle for proper application.

An all natural approach is available in the form of Bonide’s Captain Jack’s Dead Bug Brew.  Captain Jack's Deadbug Brew® contains Spinosad (spin-OH-sid), a product first isolated from a naturally occurring soil dwelling bacterium that was collected on a Caribbean island from an abandoned rum distillery. Deadbug Brew® kills bagworms, borers, beetles, caterpillars, codling moth, gypsy moth, loopers, leaf miners, spider mites, tent caterpillars, thrips and more! Use on fruits, vegetables, berries, citrus, grapes, nuts and ornamentals and approved for organic gardening.

For additional information, see the following fact sheets which are available from local university extension services:

May 19, 2016

Plum Curculio Season

plum curculio ovipositing egg
Plum Curculio Ovipositing Egg
With the petal fall being behind us, and the temperatures predicted to be near 80 this weekend, it is prime time for our ugly little friend, PC! Adult plum curculio beetles, pictured to the left, emerge in the spring, right around or just after petal fall, to feed on apple buds, flowers, leaves and young fruit. Female beetles cut holes in the young fruit and deposit one egg in each cavity.
These sites are easily identified by their crescent shaped cuts. Unlike codling moth, the larvae of plum curculio rarely cause damage to the fruit. The fruit is primarily damaged superficially by the egg-laying and feeding by the adults. These "stings" will cork over and cause an indentation in the fruit as it matures making it look deformed and unsightly. 

The question then becomes, how do we control them??  Pesticide application at this time is very important for plum curculio control. To prevent fruit drop, and due to toxicity to bees if there are still blooms on the trees, do not use carbaryl (Sevin®) or any pyrethrin based spray as these are highly toxic to honey bees and other pollinators. For home growers, an acetamiprid spray such as Ortho® Flower, Fruit & Vegetable Insect Killer Ready-Spray is a deterrent.  If no blooms are present  on any trees, a pyrethrin based spray can be used.  Picking up and disposing of any fallen fruit will reduce problems with plum curculio, other insects, and many plant diseases. For conventional growers, Avaunt or Assail are two choices you might use, based on your codling moth protocol and your apple maggot protocol.  For a pure organic spray, the two most frequently used insecticides are Surround® and Pyganic®, both certified organic. The organic products may need to be sprayed multiple times for complete control at 7 to 10 day intervals or after any rain. And, as always, follow all label directions on any spray product.

For a complete Fact Sheet on Plum Curculio, consult the Cornell University Plum Curculio Fact Sheet and for an indepth look at plum curculio management in stone and pome fruits from Michigan State University.

April 7, 2016

Critical Temperatures For Frost Damage on Fruit Trees

This spring has marked another unprecedented weather pattern that raised our temperatures in late March and lowered early April temperatures to below normal.  It seems that each spring since 2012, we have been on the verge of critical temperatures for frost damage with our fruit trees.  

As the trees develop in the spring and buds start to swell, they lose the ability to withstand the cold winter temperatures that they could withstand in dormancy during the cold winter months. The young, actively growing tissue can then be damaged or even killed. Swollen fruit buds can better withstand temperatures in the teens without any damage. As the buds open, temperatures in the low 20s can cause harm, but sometimes leave other buds undamaged.  As growth moves from green tip to 1/4” green to 1/2” green to tight cluster to pink in apple trees, temperatures in the upper 20s can cause considerable harm to an early blooming tree. Near bloom, the range between slight and severe damage can be very small. So the stage of bud development determines how susceptible any given fruit crop is when freezes occur.  For more information on what those critical temperatures are that can cause freeze damage to trees during development, I have added two charts on the Critical Temperatures For Frost Damage on Fruit Trees from Utah State University below that you can download by clicking on either chart below. 


Given the weather patterns we have experienced so far this spring, and the fact that we have gotten snow as late as mid April, a spring frost could be possible within the next few weeks.  We will need to constantly assess the stage of development our trees are at and their susceptibility to freeze injury. If we continue in this spell of colder weather, apple trees will continue to develop more slowly, but once they begin showing tight cluster and pink, the critical temperature rises from the low 20’s to the high 20s, to levels just below freezing at bloom time.  

Follow by Email