GREEN ASH: Fraxinus pennsylvanica Marsh. D. R. Smitley & T. W. Davis

EMERALD ASH BORER; Department of Entomology

Agrilus planipennis Fairmaire Michigan State University

East Lansing, MI 48824-1115

517-355-3385

tdavis@msu.edu

Mixing and applying drench treatments at Kentwood EAB trial, 2010.

EMERALD ASH BORER CONTROL IN ASH STREET TREES IN A NEIGHBORHOOD IN MICHIGAN, 2008 – 2012.   Ash street trees in two neighborhoods in the northeast corner of Kentwood, Mi were used for this test.  The trees were tagged in early Nov 2008, and were blocked based on location, trunk diameter and the number of replications required for each treatment.  The 175 trees in the southern neighborhood (42º55’54.12”N 85 º 33’11.19”W) were about 15-18 years old and were about 20 ft tall.  The trees ranged in size from 5 to 14 inches DBH with a mean of  9.8 inches.  The 50 trees in the northern neighborhood (42º56’21.67”N 85º33’16.23”W) were more mature and ranged from 9 to 20 inches DBH with a mean diameter of 15.3 inches.  The trees were marked with a numbered aluminum tag.  Treatment 0 was applied in the fall of 2008.  All of the other treatments were initiated in 2009.  The number of replications varied between 9 and 12, depending on the requirements of the company requesting the treatment.  The treatment specifics and application dates are listed in the detailed treatment descriptions below and in Table 1.  Dieback ratings were taken on 10 Jul 2009,  12 Jul 2010, 22 Jul 2011 and 10 Jul 2012  by having 2 (2009), 3 (2010), 4 (2011) or 3 (2012) samplers independently sample each tree.  The final rating value assigned to each tree was the average value for that year.  The trees were rated from 0% – no dieback, to 100% – a completely dead tree.  The mean dieback rating for each tree was converted arcsin(sqrt(1/x) before running ANOVA.

Evidence of emerald ash borer activity was obvious and widespread in the site from the beginning of the test.  Most of the trees were showing either epicormic growth, blonding (a flecking of the bark that seems to be indicative of EAB caused by woodpeckers or small mammals.  It is not a wholesale woodpecker hit), bark cracking and on some trees – dieback or a combination of symptoms.  Most of the trees in 2009, 2010 and 2011 did not exhibit any canopy dieback.  The 2009 dieback ratings should be considered a background assessment as the treatments made in 2009 would not have shown any differences in canopy dieback until 2010.  Even though there were actually statistically significant differences between treatments in 2009 and the untreated treatment was the highest, this was not due to an impact of the chemical treatments.  Usually a rating of less than 20% dieback is considered to be background, but the springs of 2010 and 2011 were wet, and the trees were full and healthy (see Table 3).  Most of the trees were assessed as having less dieback in 2010 than they had in 2009.  The fact that most of the trees in the site were treated with insecticides may have contributed to the lack of dieback, as the insects are very mobile and will move from tree to tree while feeding for several days before ovipositing, allowing for the potential of ingesting insecticide.  As a result, dieback ratings did not show any treatments as being significantly different from the controls in 2010 or in 2011.  There were trees beginning to show a fair amount of dieback as individual trees in several of the treatments were beginning to show significant dieback in 2011.  Although there were a few trees showing significant dieback, the mean per treatment was still below 11% in all of the treatments in 2011.   Tree crews from the City of Kentwood are removing trees as they reach 50% dieback.  Several neighboring homeowners convinced the crews to remove their ashes in the hopes that new trees of different species would be replanted even though their original ash was not showing significant damage.  One ash was removed that had split and was not showing any dieback.  This is the reason that several of the treatments have shown a reduction by 1 of the number of trees evaluated between 2010 and 2011.

Even though most of the treatments were below 20% overall, the dieback had increased by 2012 and significant differences between treatments were observed.  The average dieback in the untreated check treatments had increased from 6.93% in 2011 to 22.88% in 2012 (tmt 1).  The Acecap treatment from CSI was significantly different with an overall dieback of 1.51% (tmt 17).  The Experimental 2 tree injection was also significantly different with a dieback mean of 2.6% (tmt 16).

All of the Valent products: Safari 20SG spring drench (tmt 10), Safari 20SG late June drench (tmt 14), Safari 2G spring granular (tmt 11), Arena 50WDG spring drench (tmt 12) and the combination Arena/Safari (tmt 13) as a spring drench were all significantly different from the untreated check.  The spring Safari drench was a better timing with dieback at 1.17% than waiting 4-5 weeks and applying in late June (7.33%).

Both of the Merit 75 drench treatments that were applied twice (therefore at a 2x rate) (tmts 3 and 4) were significantly different from the single application (1x rate) (tmt 2) which was not significantly different from the untreated check.  The three Bayer Advanced granular treatments gave the same results in that the application that was repeated (2x – tmt was significantly different from the untreated check whereas the 2 granular treatments (tmt 0 and 6) applied a single time (1x) were not significantly different from the untreated treatment.  The Bayer Advanced liquid treatments showed the inverse in that the 1x rate was significantly different and the other two treatments applied at 2x were not significantly different from the untreated check.  There is no explanation as to why this occurred.

The data in Table 4 and Fig 1 of the neonicotinoid treatments show that rates higher than 2.25 grams active ingredient per inch diameter at breast height (DBH) were general significantly different from the untreated check.  Rates lower than 2.25 gr ai/DBH were all not significantly different than the untreated check except in one case.

April through June was much drier in 2012 than in the previous 2 years.  It is anticipated that the 2013 dieback will dramatically show differences between the treatments that are working vs the untreated check trees.  This trial will be completed with the evaluation of dieback in July of 2013.

Applying Acecap treatments 2012 Early May, 2012

Granular application, Kentwood EAB trial, 2010. Replacing damaged tags, Kentwood 2012

List of Treatments:

0)  Bayer Advanced SP102000017711 granular formulation containing imidacloprid (0.55%) & clothianidin (0.275%) (total ai – 0.825%) with DMSO and gypsum and 2-1-1 fertilizer applied at 56 grams of product per cm DBH.  142 grams of product per inch DBH was applied in a 12 inch band around the base of each tree on 26 Nov, 2008.  A small leaf rake was used to spread the chemical and to knock the granules into the grass.  This treatment was reapplied on 27 May, 2010 and on 25 May, 2011, and on16 May, 2012.  Trees 42, 58, 70, 75, 115, 150, 185, 216, 236 treated                     Tree 140 has been cut

1)        Untreated Check Trees 34, 41, 86, 106, 162, 204, 215, 230, 231, 232, 249 Originally, tree 221 was included.  It was deleted as it was treated with Tree-Age by a commercial concern.

2)        Merit 75 drench 1.9 gr prod per inch DBH applied in a 12 inch band around the base of the tree as a drench.  Merit 75 was used instead of Merit 2F, mixed 454g/5gal and sprayed at 50psi through a single wand backpack sprayer with the nozzle removed at 1L/9sec to give a metered dose based on time.  Application was on 26 May, 2009, 27 May, 2010, 25 May, 2011 and on 16 May, 2012.  Trees 54, 111, 118, 154, 176, 184, 197, 208, 225, 228, 247, 248

3)        Merit 75 drench 1.9 gr prod inch DBH applied in a 12 inch band around the base of the tree as a drench.  Merit 75 was used instead of Merit 2F, mixed 454g/5gal and sprayed at 50psi through a single wand backpack sprayer with the nozzle removed at 1L/9sec to give a metered dose based on time.  Application was on 26 May, 2009, 12 Jun, 2009, 27 May, 2010, 17 Jun, 2010, 25 May, 2011, 28 Jun, 2011, 16 May, 2012 and 20 Jun, 2012.  Trees 11, 47, 93, 97, 98, 137, 144, 172, 226, 227, 235, 238

4)        Merit 75 drench 1.9 gr prod inch DBH applied in a 12 inch band around the base of the tree as a drench.  Merit 75 was used instead of Merit 2F, mixed 454g/5gal and sprayed at 50psi through a single wand backpack sprayer with the nozzle removed at 1L/9sec to give a metered dose based on time.  Application was on 26 May, 2009, 26 Aug, 2009, 27 May, 2010, 23 Aug, 2010, 25 May, 2011, 22 Aug, 2011, and 16 May, 23 Aug, 2012.  Trees  5, 32, 89, 96, 113, 186, 199, 202, 211, 234, 240. Tree 212 has been cut

5)        Bayer Advanced liquid formulation containing imidacloprid (0.74%) & clothianidin (0.37%) (total ai – 1.11%) with green dye and 2-1-1 fertilizer applied at 36.57 ml of product per cm DBH.  92.9 ml of product per inch DBH was applied in a 12 inch band around the base of each tree on 26 May, 2009,  27 May, 2010, 25 May, 2011, and 16 May,  2012 by putting the product in a 5 gal CO₂ powered sprayer and applying a timed dose through a wand applicator with the nozzle removed.  Trees 6, 38, 99, 147, 167, 168, 173, 213, 218, 220, 242, 244.

6)        Bayer Advanced granular formulation containing imidacloprid (0.55%) & clothianidin (0.275%) (total ai – 0.825%) with DH46 applied at 56 gr of product per cm DBH.  142 gr of product per inch DBH was applied in a 12 inch band around the base of each tree on 26 May, 2009, 27 May, 2010, 25 May, 2011 and 16 May, 2012.  Trees 28, 35, 55, 65, 142, 153, 170, 209, 214, 222, 233, 239.

7)        Bayer Advanced liquid formulation containing imidacloprid (0.74%) & clothianidin (0.37%) (total ai – 1.11%) with green dye and 2-1-1 fertilizer applied at 36.57 ml of product per cm DBH.  92.9 ml of product per inch DBH was applied in a 12 inch band around the base of each tree on 26 May, 2009, 12 Jun, 2009, 27 May, 2010, 17 Jun, 2010, 27 May, 2011, 28 Jun, 201, 16 May, 2012 and 20 Jun, 2012 by putting the product in a 5 gal CO₂ powered sprayer and applying a timed dose through a wand applicator with the nozzle removed.  Trees 17, 40, 128, 145, 163, 182, 210, 219, 229, 237, 251. Tree 132 has been cut

8)        Bayer Advanced granular formulation containing imidacloprid (0.55%) & clothianidin (0.275%) (total ai – 0.825%) with DH46 applied at 56 gr of product per cm DBH.  142 gr of product per inch DBH was applied in a 12 inch band around the base of each tree on 26 May, 12 Jun, 2009, 27 May, 2010, 17 Jun, 2010 27 May, 2011, 28 Jun, 2011, 16 May, 2012 and 20 Jun, 2012.  Trees 37, 46, 66, 67, 88, 91, 100, 200, 241, 243, 253. Tree 217 has been cut

9)        Bayer Advanced liquid formulation containing imidacloprid (0.74%) & clothianidin (0.37%) (total ai – 1.11%) with green dye and 2-1-1 fertilizer applied at 73.15 ml of product per cm DBH.  185.8 ml of product per inch DBH was applied in a 12 inch band around the base of each tree on 26 May, 2009, 27 May, 2010, 27 May, 2011, and 16 May, 2012 by putting the product in a 5 gal CO₂ powered sprayer and applying a timed dose through a wand applicator with the nozzle removed.  Trees 27, 33, 61, 73, 77, 180, 188, 207, 223, 224, 250, 252.

10)     Safari 20SG at 12 gr product per inch DBH applied as a drench in a 12 inch band around the base of the tree on 3 Jun, 2009, 27 May, 2010, 27 May, 2011, and 16 May, 2012.  The amount per tree was mixed in a gallon of water and poured around the base of the tree.  Trees 24, 101, 104, 116, 146, 148, 156, 166, 175, 245.

11)     Safari 2G at 120 gr product per inch DBH was applied in a 12 inch band around the base of each tree on 3 Jun, 2009, 27 May, 2010, and 27 May, 2011.  Application skipped in 2012 as the formulation has been discontinued.  Trees 44, 49, 56, 87, 103, 105, 124, 158, 171, 183.

12)     Arena 50 WDG at 4.8 gr product per inch DBH was applied as a drench in a 12 inch band around the base of each tree on 3 Jun, 2009, 27 May, 2010, 27 May, 2011, and 16 May, 2012.  The amount per tree was mixed in a gallon of water and poured around the base of the tree.  Trees 26, 57, 59, 76, 90, 107, 112, 160, 178, 206.

13)     Arena 50 WDG at 2.4 gr and Safari 20SG at 6 gr product per inch DBH was applied as a drench in a 12 inch band around the base of each tree on 3 Jun, 2009, 4 Jun, 2010, 27 May, 2011, and 16 May, 2012.  The amount per tree was mixed in a gallon of water and poured around the base of the tree.  (Tree 123 may have been skipped in 2009).  Trees 31, 48, 52, 69, 119, 123, 126, 139, 159, 195.

14)     Safari 20SG at 12 gr product per inch DBH applied as a drench in a 12 inch band around the base of the tree on 10 Jul, 2009, 17 Jun, 2010, 28 Jun, 2011 and 20 Jun, 2012.  The amount per tree was mixed in a gallon of water and poured around the base of the tree.  Trees 36, 50, 64, 109, 114, 133, 151, 179, 193, 196.

15)     Secrecy – Experimental 1 Trunk Injection

16)     Secrecy - Experimental 2 Trunk Injection

17)     Creative Sales Incorporated ACECAP Trunk Implants (0.875 grams acephate per cap) applied on 14 May, 2009, 6 May, 2010,  again between 24 – 31 May, 2011 (multiple trips due to battery issues) and on April 25, 2012.  A single cap was placed every 4″ around the base of the tree in a 3/8 inch diameter, 3/4 inch deep hole and sealed by tapping in a plastic septum.   (Tree 122 may have also gotten dosed with tmt 13 in 2009).  Trees 83, 94, 122, 138, 164, 169, 174, 177, 191, 246.

18)    Secrecy – #9667

Table 5.  Raw dieback ratings (means per tree).

2008

A Primer On Soil Science

By

Bud Franklin

Excerpt from January 2011 Tree Tips Newsletter

For this January newsletter I thought it may be a good time to talk a little about soils and how they affect your plants.  Without a good understanding of some basic principles about soil science growing healthy trees can be quite difficult and frustrating.  It is important to understand what type of soil you are dealing with and it’s characteristics so you can better manage your cultural practices.
The first thing to understand is that for the most part you are pretty much stuck with the soil that is native to your area.  It is possible to make some minor alterations but it is important to accept that the soil you are dealing with has been evolving for approximately four and a half billion years and it is not likely that you can do anything in one afternoon to radically change the characteristics of your local soil.
The five things that affect the evolution of your soil are:

•  Parent Material:   bedrock and organic material, imported material from glaciers, volcanoes and flooding  
•  Climate :  heat, rain, ice, wind and sunshine
•  Organisms:   plants and animals – both micro and macro
•  Topography:   low lands, slopes, elevation
•  Time

     As time progresses all of these elements come together to form what we call soil. For instance, if you live in a high precipitation area with moderate temperatures you will naturally have more vegetation and animal life thus more organic matter than if you lived in the desert with low precipitation and hot temperatures.  You would also expect more parent material from sedimentation and run off.  In colder climates, because of freezing and thawing, you get a more rapid breakdown of the bedrock. Each of these five elements react with one another in a multitude of combinations that ultimately form soil.
How they interact will determine whether you have sandy soil, a loamy (silt) soil or a clay soil. The organic matter will determine if your soil is light or dark in color, it’s pH, and it’s ability to bind with other elements as well as it’s water retention capabilities.
The terms sandy, loam  (silt) and clay refer to the relative size of the particles that make up the soil.  Sand particles are the largest, loam particles are in the middle and clay particles are microscopic.  Size is important!

Relative Soil Particle Size

Because sand particles are relatively large they have large pore spaces between them which aids drainage but lacks the ability to bind or hold on to each other and other elements. This means that it will require more water and more nutrients because of leaching. On the other hand, clay particles are microscopic and have small pore space which inhibits drainage but encourages a high binding capability. This means they will need less water and less fertilization. Loam particles are in the middle range of the other two and share the characteristics of both and are generally considered to be the best for plant growth.  Sandy soils come in second because you can better control  with cultural practices than if you had a tight heavy clay soil that does not drain or allow for the movement of water, air and nutrients.

Another important characteristic is the soils pH.  This is the factor that measures the soils relative acidity or alkalinity.  Soils with high organic matter content are usually slightly acidic.  Parent material also plays a part in the pH factor.  The pH scale goes from 0  (highly acidic) to 14 (highly alkaline) with 7 being neutral.

Solubility Of Plant Nutrients

A slightly acid soil with a pH of around 6.5 is considered most desirable because it is in the range where elements such as Iron, Zinc, and Manganese are the most soluble and thus available for plant uptake.

Another important characteristic is the amount of salt present in the soil.  Overall, salt has a negative impact on both the physical attributes of the soil as well as a negative impact on plant cells.  A high content of salt is the cause of deflocculation which is a big word that basically means it prohibits the particles of the soil to bind together.  When this happens you lose all the pore space which in turn prevents drainage as well as the movement of air and nutrients.  Another problem with salt  is that because it is soluble it eventually gets picked up by the plant and if the per cent of salt content in the cell becomes to high it will kill that cell.

Salt Burn Damage On A Leaf

  Salt can originate from the parent material or accumulate from irrigation water with a high salt content.  Fortunately, if you have adequate drainage, you can leach it out of the soil profile with deep watering and get it below the root zone.

Everything I have just discussed has a bearing on how trees take certain elements out of the soil.  So to end this I need to toot my own horn here.  By using systemic implants you virtually eliminate all of the soil characteristics that have a negative impact on nutrient uptake.  The Systemic Implants put the required element or elements directly into the vascular tissue so you do not have to be concerned with drainage, leaching, solubility, pH, salt content,  etc., etc.  Toot Toot!

Tree Care-Managing Salt Burn

by

Bud Franklin

Excerpt from February 2011 Tree Tips Newsletter

In last months newsletter I mentioned the negative effects that salt accumulation has on both the soil and plant tissue.  It is such a common problem with a simple solution  that I thought it deserves a more detailed discussion.
It is not uncommon in locations of low precipitation or inadequate drainage to have a soil salt accumulation problem.  This is due to the fact that there is not enough deep penetration of water in the soil strata to move the salt below the root system.  Because salt is soluble the best way to resolve the issue is periodic deep irrigations.   This has two benefits: first it removes the salt from the root zone and secondly, with a monthly  deep watering, it encourages the roots to penetrate deeper which in turn leads to more root volume.   A more extensive root system can deliver more water, more nutrient and better plant stability.
One of the most common problems I encounter in my work is with trees grown in lawn areas or flower beds with annuals and perennials.  Because lawns and flower beds  require more frequent and shallow waterings  the land owner assumes that this will be adequate for the trees in the immediate area.  Unfortunately what results is that the tree roots over time come to the surface which causes many problems such as exposure to radical and frequent changes in the soil temperature, soil moisture, soil pH and fertility and a smaller root system that fails to  provide strength and stability.

Damage From Shallow Roots

The other major concern is the build up of salt in plant tissue.   The simple explantion of tissue damage due to salt burn is that when a high concentration of salt is on one side of a membrane and a low concentration is on the other side of the membrane the natural response is to equalize the per cent of concentration on both sides.  So what happens is that pure water will move out of a cell to dilute the concentrated solution outside of the cell.  And in doing so you dessicate the cell which is a nice word for killing the cell.  This is usually first noticed on the leaf tips and margins.

Salt Burn on Leaf Margin

This is logical if you think about it.  As the water saturated with salt moves to the extremities of the plant and the water is either utilized by the plant or transpired off the salt concentration becomes greater and greater until you have complete dessication.

As I mentioned last month the most common sources of salt are either the parent material of your soil or your irrigation water.  You should also be aware that all synthetic fertilizers are formulated as a salt because of their solubility.  Thats why a salt burn and a fertilizer burn look the same-they are the same.

So the whole point of this discussion is to get you to deep water at least once a month during the growing season.  If you do this one thing your trees will be so much healthier and happier in a year.

Tree Care and Extreme Weather

by

Bud Franklin

Excerpt from Aug 2012 Tree Tips Newsletter

For those of you who are first timers, this newsletter is provided to share information about the care and maintenance of our wonderful trees. They provide so many benefits to our lives: Oxygen, shade, beauty, balance, habitat and so much more.  Like our bodies, as they grow and mature they need more of the resources that were once taken for granted in youth. If grown in the wild they would have to accept the consequences of what nature provided. However, when we plant them in our yards we have the ability to control, adjust and extend those resources so that a plant can live a long and healthy and beautiful life.

There are, however, some elements beyond our control.  The weather this summer was a prime example.  From record breaking temperatures in all 50 states, flooding along the Missouri, Ohio, Mississippi Rivers and their tributaries.  Tornadoes in the midwest and the south, droughts in Texas, and Haboobs (duststorm) in the desert. I had to use that word.

Haboob (Arizona Republic)

These weather conditions can be expected to effect your trees both in the short term and the long term.  Some of the short term problems are:

•            Wind, Hail and Lightning-broken and damaged roots, trunk, branches and foliage.

•            Drought- foliage dessication, branch die back, older leaf drop.

•            Soil Saturation-disease and weakened and unstable root system.

The long term problems can be more subtle and slower to manifest.  All of the above problems can cause the tree to produce fewer carbohydrates which in time will produce less root development, less growth, more chlorosis of the foliage and impact the reproductive cycle.  Physical damage can pose a risk to both you, your neighbors and your tree.  The damaged area, if not repaired, can offer a site for insect or disease infestation.

Bradford Pear Wind Damage

Drought can create a situation that lowers the trees natural resistance to insect and disease.

Bark Beetle Damage on Pine Trees

Soil saturation by water can cause a weakened root system and an environment susceptible to disease as well as the lack of nutrient uptake.

Uprooted Tree-Soil Saturation & High Winds

When these unusual weather patterns strike-damage occurs but a well maintained tree is the best defense.  Proper irrigation (deeply once a month for mature trees), fertilization and proper pruning go a long way to prevent unnecessary damage.  Medicap MD, Medicap FE, Phoscap, Medicap MN and Medicap ZN are systemic nutrient implants that will prevent most nutrient deficiencies.  Late summer or early fall is the ideal time to use Medicap MD .  It is the complete nutrient implant designed to last for multiple seasons and prevent many symptoms which result from nutrient deficiency brought on by stress and severe weather.

Pruning

By Bud Franklin

Excerpted from Tree Tips Newsletter Nov 2011

Pruning is a cultural practice that needs to be done every few years to eliminate any dead, diseased or damaged branches as well as to enhance the shape of the canopy and to allow for the penetration of light.  In other words to improve safety, health, and aesthetics.

Pruning is an art as much as a skill.  Those who attempt to do it themselves need to have a vision of what that tree should look like upon completion, an understanding of good pruning technique and the proper tools.  If your not ready to acquire these you should probably call a professional.

What should a tree look like on completion?  Every species has a different growth pattern.  An elm, maple and oak have canopies that could be described as oval whereas firs, spruce and cypress could be described as pyramid and columnar.

Common Tree Shapes

So before you start try to figure out what the natural growth pattern should be,  stand back and try to visualize what branches need to stay and which need to go.  Always start this process by removing dead wood first.

What is the correct way to make a cut?  Always cut back to the next branch while leaving what is referred to as the collar.

Collar Pruning Cut

If done properly this will expedite the healing process. When removing large branches make two cuts, the first further out on the limb and the second by the collar.  This will prevent peeling the bark down the trunk. Do not leave stubs as this will promote suckers, possible dieback and an unnatural  appearance.  I always recommend using LacBalsam to dress the wound.  This also promotes healing and inhibits insect or disease infestation.

Good pruning tools can get a little pricey but they are worth every penny.  At a minimum you will need a good bypass pruner, a lopper, a pruning saw and perhaps a pole pruner/saw.  Corona makes a good product that is usually available at most retailers.

Galls

By Bud Franklin

Excerpted from January 2012 Tree Tips Newsletter

Galls are growths on a plant that are caused by an external pest, i.e. insect, bacteria, fungi, virus, parasite or nematode. They can appear on any part of the plant-leaf, flower, twig, branch, trunk or root.  They can range in size from hardly visible to quite large.

These abnormal growths are caused by an interaction between the host plants meristematic tissue (that tissue responsible for cell division) and the pest organism.  For instance, in the case of galls caused by wasps the larvae inject the meristematic tissue with a chemical that initiates the growth.  The larvae then has both shelter and nourishment during its development stage.

Surprisingly, galls are rarely  lethal to a plant.  They are, however, very unattractive and can cause an inherent weakness in the affected plant part.  Once they have been initiated they will not go away unless of course they are on a leaf or twig which eventually drops. The only way to prevent a gall from forming is to eliminate the pest organism prior to it’s having the opportunity to initiate the process.  In my experience, most ornamental tree galls are caused by insects which can be controlled with Acecap. Of course this must be applied prior to infestation so timing can be an issue.  Fortunately, Acecap is a season long systemic so if you are aware of gall formation in prior season an early spring application should be effective.

Leaf Gall

Root Gall

Trunk Gall

Contact: Eric Day, Manager, Insect Identification Laboratory
Publication Number 444-216, August 1996

Bark Beetles
Coleoptera: Scolytidae, several species.

Over 600 beetles in the family Scolytidae are commonly referred to as bark beetles. Species identification is difficult because nearly all bark beetles are black or brown, cylindrical, hard- shelled, and between 1/8 and 1/3 inch long. Luckily, similarities in their life cycles and in the injury they cause usually make species determination unnecessary for making control decisions.

Adult bark beetles bore through the bark to the cambium layer of suitable host trees. Females excavate a tunnel between the bark and wood along which they lay their eggs. Upon hatching, each grub burrows away from the egg tunnel and feeds on the live bark tissue (phloem) and outer cell layers of wood (xylem). The resulting network of egg and larval tunnels beneath the bark is called a gallery. The “shot hole” appearance of the bark in infested trees indicates that numerous beetles have matured, chewed exit holes, and flown off to find new breeding sites. From one to six generations per year are typical depending on the species.

As a general rule, bark beetles attack trees that are weakened or dying due to stress factors such as drought, disease, smog, mechanical injury, or alteration of the water table and root damage due to nearby construction. They are also attracted to recently cut wood which still has bark. In pines, resin often oozes from the bark where beetles first attack, producing conspicuous pitch tubes. Some beetles become trapped in the pitch and die. A healthy tree produces enough pitch to prevent successful attack by many beetles, but sometimes by sheer numbers alone bark beetles are able to overwhelm and kill healthy trees. This may happen to trees which are near heavily infested breeding sites. Once a bark beetle is successfully established in a tree, it emits a chemical called a pheromone which attracts other beetles to the same tree. Once infested, trees almost never recover and control efforts are usually futile. Bark beetles do not attack trees and wood that are dead and dried, nor dying or recently cut wood if the bark is removed.

Several of our most common types of bark beetles are listed below, along with characters which should help you identify them. Remember that there are many other species which may be encountered in shade trees and wooded areas from time to time.

Ips Beetles
Bark beetles in the genus Ips are commonly called engraver beetles or simply Ips beetles. They can be distinguished from other bark beetles by their scooped-out hind ends. Ips galleries, found in pines, have egg tunnels in the form of an H or a Y. Though capable of attacking the entire tree, Ips beetles are usually confined to the crown.

Southern Pine Beetle
One of our smaller bark beetles, the southern pine beetle is barely 3/16 inch long. Following long, dry spells or poor forest management, outbreaks occur that rapidly kill large areas of pine forests. Southern pine beetles attack mainly the middle or upper part of the tree trunk. All ages and sizes of pine trees are potential hosts. Their egg and larval tunnels wind around in an unorganized pattern. Healthy, vigorous trees and proper forest management practices reduce the likelihood of outbreaks and tree losses.

Black Turpentine Beetle
This beetle is large for a bark beetle, about 1/3 inch long. It attacks pine trees at the base of the trunk, and may also breed in stumps. Black turpentine beetle grubs feed together and excavate large patches under the bark. A common characteristic of this beetle’s attack is the presence of a glob of pitch, about 1/2 inch in diameter, at the exit hole. Sometimes there will be large numbers of white pitch globs on the dark bark.

Elm Bark Beetles
There are two species of bark beetles which attack elms. Both of them are capable of transmitting Dutch elm disease when they feed on healthy trees. The European elm bark beetle feeds in the crotches of one- to three-year-old-twigs; the native elm bark beetle feeds in the thick bark of trunks and limbs. Native elm bark beetles construct egg tunnels across the wood grain. Egg tunnels of the European elm bark beetle are parallel to the grain. Both make galleries and breed only in recently killed or dying elm wood three inches or larger in diameter.

Other common bark beetles include: Shothole Borer which attacks fruit trees, wild cherry, serviceberry, and occasionally elm; Peach Bark Beetle in stone fruits, mountain ash, elm, and mulberry; Pityogenes spp. and Pityophthorus spp. in pines; Phloeosinus spp. in cypress and junipers; Ash Bark Beetle in ash; Birch Bark Beetle in birch, beech, wild cherry and red gum; and Hickory Bark Beetle in hickory.

On healthy trees bark beetles may attack individual twigs and branches that are dying from shading out or other causes. For example, some species breed only in the dead or dying twigs, branches, and limbs of pines. These bark beetles will not breed in live branches, and thus are not a progressive destructive threat to healthy parts of trees.

Control
The old adage about an ounce of prevention being worth a pound of cure is especially appropriate here. Once a tree becomes infested with bark beetles, it usually dies rapidly. Bark beetles attack weakened, stressed, or dying trees. Preventative measures include: 1.) maintaining healthy, vigorous trees; 2.) eliminating beetle breeding sites, such as recently dead or cut trees, limbs, slash, and firewood with bark; and 3.) applying residual insecticides to susceptible but as yet uninfested trees, especially those under stress and therefore attractive to bark beetles. Treating infested materials before bark beetles emerge will kill them as they chew their exit holes. Check the Virginia Pest Management Guides for current insecticide recommendations. Always read and follow the instructions on the pesticide label.

Revised by Eric Day. Department of Entomology, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0319.

Background
Arizona is currently experiencing an infestation of bark beetles that are contributing to the demise of hundreds of thousands of pine trees. The two beetles responsible for this attack are the Pine Engraver Beetle and the Western Pine Beetle. Although many species of pine are being attacked, the Ponderosa and the Pinyon seem to be taking the heaviest losses. These beetles are always present in nature. A healthy and vigorous tree usually has the ability to pitch out attacking beetles thus preventing colonization. The reason we are seeing the tremendous loss this year is because of the drought, which we are currently experiencing. In a normal year the pines would be metabolizing, moving water and nutrients up the xylem and carbohydrates down the phloem. Because of the lack of moisture in the root zone this process has been completely shut down or nearly so. In fact, there are those who are beginning to believe that many of the losses are caused as much by a lack of water and nutrients as by the beetle itself. However, it is true that in this state of near dormancy the plant becomes totally unable to fight off an attack.

Control
The focus of any control program must be to return the tree to a healthy and vigorous state. Your first line of defense is to act now and try to eliminate as many points of stress as possible. This can be achieved using the following steps:

1. Watering: It is extremely important to initiate a watering program that will replenish the moisture in the feeder root zone. This is an area that encompasses twice the diameter of the drip zone to a depth of anywhere from 2 feet to 15 feet depending on the size and age of the tree as well as the soil characteristics. This watering program should replenish the moisture in this zone at least once a month throughout the entire year. There are numerous ways to accomplish this depending on the availability of water, the topography and the soil. If water is in short supply the following technique seems to accomplish this task with the least amount of water. Using a 4” diameter perforated PVC pipe 4 ft long (optimum) bury vertically at 5 ft intervals below the drip line. Fill the pipes with pea gravel. Using a hose fill the pipes with water until saturation occurs once a month. Another method is to dig a trench 4” deep and 6” wide around the drip zone and run water until saturation. The easy method is to use a lawn sprinkler under the drip zone and beyond and allow to run for 6 to 12 hours. This method is the least effective use of water because of evaporation and runoff. Drip irrigation techniques are typically not effective because of the limited application area as well as low water output unless left on for a very long duration.

2. Implants: Trunk implants should be used to address two issues: 1) nutrient deficiency and 2) insecticide placement. Because the plant is near stress induced dormancy, it is unlikely that it has the ability to uptake the adequate amount of nutrient via the root system. By using an injectable fertilizer, it is possible to bypass the stressed root system as well avoiding any problems associated with soil chemistry. I recommend Medicap MD 3/8” implants containing a complete fertilizer with an analysis of 12-4-4 with Iron, Zinc and Manganese. This application technique has been documented to last in the tree for periods of 24 to 36 months while providing all the elements necessary for vigorous plant growth.

As far as the insecticide is concerned, by injecting, it is possible to maximize control with the minimal amount of chemical, eliminate concerns for over spray or spray drift which could negatively impact wildlife, and container disposal issues. Acecap 97 is recommended because of numerous factors. First, the active ingredient is Acephate, a proven insecticide with both contact and systemic action. It has been shown to be active in pines for periods up to a year. Secondly, it is one of the safest insecticides on the market as far as the LD50. This product is non-restricted and can be used by the homeowner.

• Application Technique: When applying both Medicap MD and Acecap 97 simultaneously it is recommended that an implant is placed every 2 ½ inches to 3 inches around the circumference in a stair step fashion. See manufacturers label for additional information.

3. Sanitation: Remove all dead and dying plants. These plants are breeding grounds and will become a source of additional infestations next spring.

4. Thinning: Thin unwanted vegetation around pines. This will eliminate other plants from competing for water and nutrients.

Summary
ACT NOW! Once a tree has been colonized in all likelihood it will die. Address every issue which could be causing undue stress to the plant and make every effort to eliminate the cause. Use tree implants for fast, efficient and safe results. Remove dead plants and plant material from the immediate area. Thin area of unwanted vegetation to eliminate competition.

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Systemic Implants

by

Bud Franklin

October 30, 2003

The professional tree industry is continuously searching for more effective means of treating trees with nutritional and pest problems. There are numerous methods which can be employed to deliver nutrients and pesticides to plant material and this article’s intent is to discuss those and briefly outline advantages and disadvantages of each.

Plant Nutrients
A brief discussion of how plants take up nutrients is a good place to start. Nutrients such as hydrogen, oxygen and carbon (as in CO2) are present in the atmosphere and the plant absorbs these in relatively large quantities and under normal conditions it is not necessary to further amend these. Macro nutrients, nitrogen, phosphorus, potassium, calcium, sulfur and magnesium are also used in relatively large quantities but are absorbed via the root system. Nutrients referred to as micro-nutrients, iron, zinc, manganese, copper, boron, chloride, and molybdenum, are used in smaller quantities and are also absorbed by the root system. All of these nutrients are necessary for healthy plant growth and they are only categorized to distinguish the relative amounts used by the plant. If any of these nutrients are lacking, out of balance, or are not in the appropriate form the plant can utilize, the plant will experience negative consequences. Under normal growing conditions root hairs on the roots absorb water and dissolved nutrients. Many factors can have an effect on this very important process. To mention a few the root hairs must be present and functioning, nutrients (macro and micro) must not only be present but also in a soluble form, the soil or growth medium must have the proper characteristics to release the nutrients (cation exchange capacity, correct pH, functioning bio flora) and of course the correct water to air ratio in the soil.

Supplemental Nutrients
There are basically three methods to supplement nutrients. These are soil applied, foliar applied or implants and injection. Soil applied nutrients can be applied by dry fertilizer applications to the surface or liquid applications via root feeders or soil drenches. This is probably the most common approach to addressing nutrient deficiency problems and if it is done properly and periodically (two to three times a year) one can expect to achieve the desired results. There are, however, some areas of concern. First, with any soil application there can be an extended period of time before results can be observed. This is due to all the interactions that must take place between the soil, the nutrient, and external environmental factors before the plant can benefit from the application. Secondly, when using this approach it is necessary to use more material than the plant needs because much of what is applied is either ultimately tied up in the soil or leached below the root zone. Additionally, many synthetic fertilizers are formulated as a salt which over the long term can have a negative impact on soil structure and chemistry as well as plant growth. Soil applications are the only way to address issues in which you are trying to correct adverse soil conditions such as high acidity or alkalinity. Foliar applied nutrients have the advantage of quick response time but the disadvantages of short duration and the difficulty of treating large trees. Additionally, any type of foliar application of nutrient or pesticide has substantial environmental aspects. Drift to non-target plants and animals is a common problem. In the case of nutrient foliar applications this is not normally a concern but it should always be a consideration. However, drift from foliar applications of pesticides can have a major negative impact on non target plants, wildlife and domestic animals. When using this approach it is always extremely important to consider volatility, temperature, wind speed and direction as well a complete evaluation of all non-target organisms in the immediate area which may be exposed to overspray and drift.

Systemic Implanting
Systemic implanting is a method of nutrient application which addresses some of the issues with soil and foliar applications. First, the results are observed within weeks of the application. This is due to the fact the nutrient is implanted directly into the vascular tissue of the plant and is immediately available. Because of the vascular placement, systemic implants are an excellent way to apply nutrient when a plant is in a stress situation such as drought, damage from weather, construction, confined planters, fire or other external factors. Secondly, it is not unusual to control the deficiency for periods of two to three years. Thirdly, it is an environmentally safe way to apply nutrient because of the very small amounts of material needed to correct the problem and the closed system of application which has no negative impact on the soil or atmospheric environment. It is easy to apply and cost effective when you factor the length of control. Systemic implants can also be used to control insect infestations in most ornamental trees. Acecap 97 is a systemic implant containing Acephate, a non-restricted use broad spectrum insecticide, which is easy to use and requires no specialized application equipment or protective clothing. Non-target organisms, people, plants, wildlife and domestic animals are not endangered by this application technique when used according to the label.

Large ornamental trees are a priceless element to our urban and rural landscapes. Their value cannot be expressed in dollars. Unfortunately, there are conditions, sometimes created by nature and sometimes created by humans, that can put these priceless plants at risk. If such an occasion should occur systemic implants offer a unique therapy to return your trees to a healthy and vigorous state. When properly used, you can cure stressed and injured trees in the shortest amount of time, affordably and in an environmentally sound manner.