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Vol. 23, No. 3, April 18, 2008

In this issue
Landscape and nursery

Emerald ash borer treatment products for professionals

Emerald ash borer treatments for the homeowner

Tree-Äge (emamectin benzoate) receives SLN registration for control of emerald ash borer in Michigan

European chafer damage to home lawns is showing now

Home lawn grub control

Early season nursery crop disease management
Turfgrass

Patching up lawns
Christmas trees and forestry

Envidor labled for Christmas trees

Nitrogen application for Fraser fir

Pre-emergence herbicides for use in Christmas tree plantations

Gypsy moth 2008 spray window dates and map
Around the home

Red squirrel injury to spruce
Other news

Changes to Pesticide Regulation 637 are in effect immediately

Weather news

Next Issue May 2

Emerald ash borer treatment products for professionals
Dave Smitley, Entomology

Several insecticide products have worked well in research tests for control of emerald ash borer (EAB) in individual trees. At this time, treatments are needed every year for all the products in Table 1 with the exception of Tree-Äge which can be trunk-injected every other year. Tests have shown that we can protect healthy trees from emerald ash borer with insecticides, but successful protection of compromised trees is less likely. By the time you see canopy thinning, dead branches and woodpecker activity, the tree is already severely damaged, and it may be too late to save with insecticides. The most effective products appear to be working on trees with up to 50 percent canopy thinning, although the recovery from EAB damage is slow, with the trees looking a little better each year after treatment begins.

Imidacloprid basal soil injections or basal drenches should start when trees are still healthy (zero to 25 percent canopy thinning and dieback), because large trees (greater than 10-inches dbh) may not be protected well in the first year after basal soil drenches. Also, large trees should be watered during dry periods to maximize control with imidacloprid basal soil applications, and to maintain tree health.

Trunk injections and foliar sprays should also begin when trees still appear healthy. Some imidacloprid or bidrin trunk injection products have provided reliable control when treatments are made every year. Arborists should consider combining trunk injection treatments with a basal soil drench or foliar sprays for the first year or two when attempting to save trees that are already infested with EAB.
The products listed in the accompanying table will help protect trees from emerald ash borer if treatments begin when trees are still healthy. For more information on how well each of these products work, see reports of our research tests at http://emeraldashborer.info/. At the website, you will see a list of topics on the left side of your screen. Just click on research and you will find reports from at least five different EAB insecticide tests.

Table 1. List of products labeled for protecting ash trees from emerald ash borer.

Active Ingredient	Product name	Timing	Type of Application
Imidacloprid	Imicide (Mauget) Pointer (Wedgle) IMA-jet (Arborjet) Merit Tree Injection	Late May to late June for control in current year.	Trunk injection (once per year)
Emamectin	Tree-Age	Late May to late June for control in current year.	Trunk injection (once every two years)
Bidrin	Injectacide-B	Late May to early September	Trunk injection (once per year)
Imidacloprid	Merit	April to early June	High pressure basal soil injection (once) or basal soil drench
Dinotefuron	Safari	Late May or June	Trunk spray
Cyfluthrin	Tempo	Early June and again in late June	Trunk and foliage spray (twice)
Bifenthrin	Onyx	Early June and again in late June	Trunk spray (twice)

Note: This information is for educational purposes only. Reference to commercial products or trade names does not imply endorsement by MSU Extension or bias against those not mentioned.

Emerald ash borer treatments for the homeowner
Dave Smitley, Entomology

Homeowners have the option of protecting ash trees from emerald ash borer by using imidacloprid as a basal soil drench. Imidacloprid is available to homeowners at local garden centers as Bayer Advanced Tree and Shrub Insect Control. The product is mixed in a bucket of water at the concentration of 1.0 ounce of product per inch of trunk circumference. The bucket of solution should be mixed and poured around the base of the trunk in May or early June. Treatments should begin when trees are healthy. Repeat this treatment each year.
The cost of treating an ash tree with a 32-inch circumference is about $22 to $26 per year. Several field trials have been conducted using this treatment method with very good results (greater than 80 percent success with trees starting with less than 50 percent canopy thinning), and nearly 100 percent success with small ash trees (less than 20-inch circumference).

Failures to save ash trees with this treatment are most likely to occur with large trees growing in dry soils. More detailed information and pictures are in the MSU Extension bulletin E2955 Homeowner Guide to Emerald Ash Borer Treatment. The bulletin can be viewed and downloaded at http://emeraldashborer.info/files/E2955.pdf.

Tree-Äge receives Michigan SLN registration for control of emerald ash borer
David Smitley and Deborah McCullough, Entomology

The Michigan Department of Agriculture has approved a special local needs (SLN) registration for Tree-Äge under section 24(c) of the Federal Insecticide Fungicide and Rodenticide Act. The registration is effective April 1, 2008. You may have heard this new trunk injection product referred to as emamectin benzoate or EM. This product was tested and developed for control of emerald ash borer as a result of a cooperative research project with Michigan State University, Syngenta and Arborjet. Results from an efficacy test in Troy, Michigan conducted by. David Smitley indicate that you can expect 95 percent control or better for two growing seasons after a late May or June trunk injection.

In a 2007 study led by Deborah McCullough and Therese Poland, 100 percent of adult EAB beetles that fed on leaves from treated trees died in bioassays conducted during the summer. The density of live larvae in treated trees was 99 percent lower than the density of larvae in untreated trees on the same sites. Although several additional studies are underway, at this point it appears that Tree-Äge will provide excellent control of EAB for two years. More information about the Tree-Äge product is available on the http://emeraldashborer.info/ web site. Special registrations for this product were also approved this spring in West Virginia, Indiana and Ohio.

European chafer damage to home lawns is showing now
Dave Smitley, Entomology

In many cities in the southern half of the Lower Peninsula and a few in the northern Lower Peninsula (like Traverse City and Alpena), bare spots are showing in home lawns due to European chafer grubs consuming turf roots. Outbreaks from European chafer are most likely in lawns that were dry last summer and fall.

European chafer grub damage will continue for another two weeks in the southern Lower Peninsula and for another 3 to 4 weeks in the northern Lower Peninsula. Damage can be stopped and the grubs controlled by applying Dylox or Sevin to the affected area. Allow these products about one week to work before re-seeding the bare patches. There is no point in treating with insecticide after May 10, because the damage will be over for this spring.

European chafer grub damage found at the Natural Science Building April 14.

Home lawn grub control
Terry Davis, Entomology

I have noticed dead patches in a number of yards along my way to and from Michigan State in the last two weeks. The rain we have had the last week or so will make it very clear where there are grubs actively feeding. Dead patches in lawns – especially lawns with sandy soil and areas that have a slope to them are likely places for grubs to be active now. If you see a dead patch, dig up a few shovelfuls of soil at the edge of the bare spot and look for 5/8-inch long, c-shaped grubs. These are more than likely the larvae of European chafer if they are found in non-irrigated turfgrass. European chafer can suddenly appear and devastate a lawn with no warning as the adults are active at dusk during late June and early July and can easily be missed as they move out of the soil and congregate in trees. Since they move back into the grass and lay eggs about 11:00 PM, the average person would never notice them unless they were carefully looking for them as the sun sets. Reports have also been coming in indicating a lot of grub activity in the Brighton, Cheboygan and Alpena areas. This is the first year we have heard about extensive damage occurring so far north in addition to the normal reports from the southern part of the Lower Peninsula.

Grub damage on turfgrass.

I went to several of the local lawn and garden centers in the Lansing area to see what kinds of products are available that specifically claim they will work for grub control. I noticed a considerable amount of overlap between brands and active ingredients and products carried by different distributors. Since curative grub products, preventive grub products and snake oil were all in the same areas of these stores, I suspect a large number of homeowners have bought and applied things that will not do what they thought they would. Several of the bags had claims on them that are a little inflated. The assumption that any product claiming to kill grubs will really work is wrong. It is also important to remember that healthy turf, especially if there is plenty of rain in the spring and fall can support a grub population of five grubs per square foot with no obvious turf damage. If the grub population is high, or if there is a history of damage in an area, it may be necessary to consider using chemicals for grub control.

There are basically two ways to approach grub control. Curative compounds should be applied when the grubs are present and active. Approaching grub control from the curative standpoint avoids unnecessary applications of chemical, but is not quite as effective as the preventive products. Preventive compounds must be applied at the time of egg hatching or when grubs are small to be effective. The first critical issue is to determine what active ingredient the product contains by looking at the label.

Do not use products containing only lambda-cyhalothrin, bifenthrin, deltamethrin, cyfluthrin and permethrin for grub control. Products containing these ingredients will not work for grub control when applied to the soil surface as the active compound will bind with organic material and will not move down to where the grubs are feeding. These products work well for turf feeding insects that live on the grass leaves or soil surface, but not for insects that feed on the roots. There are a few combination products that also include imidacloprid – read on to the next paragraph. I found a product called Triazicide (containing lambda-cyhalothrin) and another called Eight (containing permethrin) in rounds. I did find other products containing permethrin, but they were properly labeled as to controlling surface insects and not soil dwelling insects. Last year, I found two granular products that contained permethrin that indicated on the bag that they would work for grub control – they will not.

Products containing imidacloprid or halofenozide will not control grubs in the spring. They are preventive products and do not work well for large grubs.

Grubs as they would appear in the spring.

Although the bag often says apply anytime from May to Aug 15, it is highly recommended that these products be applied and irrigated into the soil during the first two weeks of July. If applied now, they will have little or no effect on the grubs currently in the lawn and furthermore, they will degrade by the end of July when the chemical works well for killing the newly hatched grubs. I specifically saw Scotts Grub-Ex, Bayer Advanced Season Long Grub Control w/Merit, Bayer Advanced Complete Insect Killer (which contains both imidacloprid and cyfluthrin), a product called Grub and Lawn Insect Control and Spectracide One Stop Once & Done that contained one of these active ingredients currently in stores. If applied in early July and watered into the ground, these products will give 90-100 percent grub control. They will cost $140 to $250 to treat an acre of turf.

What to use now
Any products that contains carbaryl (Sevin) or trichlorfon (Dylox) will work well when applied in the spring (from March to mid-May) or in the fall (September 1 to November 1). These are considered curative compounds as opposed to the preventive compounds mentioned above and will kill the grubs currently in the ground. It is necessary to irrigate after applying any curative product to get the chemical to the grubs. Run a lawn sprinkler for at least 60 minutes over treated areas (fill a bucket to ½-inch). It will take 10-14 days for the grubs to begin to die. One trichlorfon product called Bayer Advanced 24 Hour Grub Control states that it will kill grubs in 24 hours. However, I doubt that any of the insecticides will kill grubs in the soil in much less than five days unless there is rain and very warm temperatures. Do not apply any curative compound after May 15 as the grubs stop feeding in late May. These “curative” compounds will typically give 65-85 percent control of grubs and will cost $150 to $303 to treat an acre.

In summary
Check the bag to determine what active ingredient the product contains.

Do not use products containing only lambda-cyhalothin, bifenthrin, deltamethrin, cyfluthrin or permethrin for any phase of grub control.

Do not use preventive compounds such as halfenozide or imidacloprid now. Use them during the first two weeks of July to control grubs that would be damaging turf in the fall.

To kill grubs in the spring use carbaryl or trichlorfon and irrigate.

Always wear rubber gloves and rubber boots when applying insecticides to turfgrass. Make sure to irrigate the lawn with at least ½-inch of water and allow the grass to dry before allowing anyone (or pets) into the treated area.

A short list of products now being sold for grub control as of April 18

Sevin-Lawn Insect Granules (20 lb bag) Various manufacturers carbaryl 2.0% 9 lb/1000 ft2 Apply in spring or fall to active grubs.	Grub & Lawn Insect Control (15 lb bag) Made by DowAgro halofenozide 1.5% 3 lbs/1000 ft2 Apply in early July.
24 hr Grub Killer Plus (15 lb bag) Made by Bayer Advanced trichlorfon 6.2% 3 lbs/1000 ft2 Apply in spring or fall to active grubs.	Grub and Lawn Insect Control (15 lb bag) Packaged by Meiers halofenozide 1.5% 3 lbs/1000 ft2 Apply in early July.
Complete Insect Killer (10 lb bag) Made by Bayer Advanced cyfluthrin 0.05% and imidacloprid 0.15% 3 lbs/1000 ft2 Apply in early July.	Eight (ready to spray – lists white grubs on bottle) made by Bonide permethrin liquid spray for hose applicator Will not kill grubs at any rate.
GrubEx (14.35 lb bag) Made by Scotts imidacloprid 0.2% 2.87 lb/1000 ft2 Apply in early July.	Triazicide Once and Done Insect Killer Granules(10 lb bag) Made by Spectracide lambda cyhalothrin 0.1% Will not kill grubs at any rate.
Season Long Grub Control (14.35 lb bag) Made by Bayer Advanced imidacloprid 0.2% 2.87 lb/1000 ft2 Apply in early July.

Early season nursery crop disease management
Thomas Dudek, MSU Extension educator

Bacterial blight on lilac
Nursery growers should be on a routine copper fungicide program to help reduce the spread of bacterial blight, especially when lilacs are overwintered in polyhouses. Prune out and destroy any infected shoots as soon as symptoms appear. Be sure to disinfect cutting tools between cuts. Overhead watering increases the spread of bacterial blight and condensation in polyhouses and can also spread the bacteria on to the plant.

Beware that freezing temperatures in polyhouses that have plants leafing out can also increase the risk of bacterial blight. If irrigation for frost protection is necessary, be sure to apply a copper fungicide within 12 hours prior to irrigating for frost protection.

Dogwood anthracnose
Growers with flowering dogwood trees affected by dogwood anthracnose should begin fungicide treatments as soon as the first leaves emerge. Apply Banner Maxx every 28 days throughout the period of leaf and shoot development. Avoid overhead irrigation if possible and irrigate with drip or direct soil application.

Immediately upon arrival of new stock, remove and burn small dead twigs from the canopy. Do not allow any of the twigs to remain on the ground where stock is held. Prune off all epitomic shoots and water sprouts as soon as they appear.

Most species and hybrids of cornus are resistant to this disease except C.florida and C.kousa ‘Autumn Rose,’ ‘Moonbeam’ and ‘Wolf Eyes.’ ‘Spring Grove’ and ‘Sunset’ cultivars are resistant. Consider offering these to your customers.

Sphaeropsis blight (a.k.a. Diplodia)
This twig blight disease of two and three needle pine species will start to show up in the spring as the buds begin to break. Nurseries trying to manage this disease need to scout Austrian pine closely and just prior to bud break, make a fungicide application and two more at 10 day intervals. Options include: Spectro 90, Camelot, Protect T/O,Junction or Banner Maxx. Or apply Clearys 3336 plus a spreader sticker or apply Heritage as per label instructions.

Powdery mildew on Scabiosa
Perennial growers who grow Scabiosa (pincushion flower) in the greenhouse have noted an increase in powdery mildew over the past couple of weeks. Look for the white flour-like dust on the leaves. This disease does not require wet foliage for development. Maintain good humidity control to reduce the infection and spread. If possible, space plants as much as possible if growing a susceptible crop like this. Powdery mildew is well known for its ability to adapt and develop resistance to fungicides, and it is important to rotate among fungicides with different modes of action. Using as few sprays as possible also helps to delay the development of resistance. Fungicide options include:

Heavy pressure: Eagle or Terraguard.
Light pressure: Compass, Zyban, Heritage, Insignia or Strike.

Patching up lawns
Kevin Frank, Crop and Soil Sciences

Now that the grass is finally turning green and starting to grow, we’re seeing what is alive and what is dead. This last winter was definitely full of plenty of snow and no doubt you’ve probably noticed some snow mold damaged areas throughout the turf landscape. In most cases, the snow mold has probably not killed the turf but has simply killed all of the leaf tissue. I’ll give you the classic two-option scenario for dealing with snow mold. The first option is to use a leaf rake to remove the dead leaf tissue and open up the canopy to allow the new growth to sprout through. The second option is to go back inside and sit down and let the grass poke through on its own. Option one will probably get the grass back growing a little quicker and will help you knock off the rust from your raking tools.
Early reports say this could be a nasty spring for European chafer grub damage as I received a report from the Flint area of grub feeding as early as late March. The recommendation is to wait one week after applying a grub insecticide before reseeding the area, otherwise the seed will be a nice snack for those grubs.

It is perfectly safe to apply fertilizer at the time of seeding. A starter fertilizer typically has a nitrogen to phosphate ratio of 1:1 or 1:1.5. A starter fertilizer application at seeding will prove beneficial in getting the young seedlings going. Typical application rates for a starter fertilizer at seeding are 1 lb. N/1000 sq. ft. Make sure to keep the seeded area moist throughout establishment. In many cases, this may require watering several times a day. A good mulch cover will help the area stay moist so the site may be watered less frequently. Water lightly when irrigating, there is no need to see water standing or running off the site.

If you’re reseeding turf areas, make sure to avoid applying herbicides this spring, i.e. no fertilizer + crabgrass preventer or weed and feed products. Young seedlings don’t tolerate herbicides very well, and the guideline is usually to wait three "real" mowings before applying any herbicides or in some cases at least 60 days. By "real" mowings, I mean you’re actually cutting significant grass, not just running over the area to trim down any weeds.

Preemergence crabgrass herbicide timing
Currently, most of the southern Lower Peninsula of Michigan is at the optimum time for making a preemergence herbicide application to prevent crabgrass. Check out www.gddtracker.net for daily updates on timing applications.

Envidor labled for Christmas trees
Jill O’Donnell
Christmas Tree ICM educator

Michigan was one of ten states that received a supplemental label for Envidor use in Christmas trees. ENVIDOR® 2 SC Miticide (spirodiclofen) is a selective foliar miticide belonging to a new chemical class called tetronic acids. The product has a unique mode of action classified as a lipid biosynthesis inhibitor (LBI) and is active by contact against all developmental stages of mites, including eggs, nymphs and female adults. Always read and follow label instructions. View instructions at: http://www.ipm.msu.edu/cat08land/pdf/4-18envidor.pdf

Nitrogen application for Fraser fir
Jill O’Donnell
Christmas Tree ICM educator

Application of commercial fertilizer materials has become an essential part of plantation management for many Christmas tree producers. Soil testing, foliar analyses and observance of tree growth and response are all used in establishing the need for fertilization in Christmas tree plantations. The potential exists to improve the growth and quality of many Christmas tree species through fertilization. However, for fertilization to be most effective, other environmental factors affecting tree growth such as the right site for the species, soil moisture considerations and effective weed control need to be in place.

Growers have used several approaches to nitrogen fertilization depending on their objectives and the particular site. One common approach is to make annual applications of about 40 to 100 pounds of actual nitrogen per acre after the first or second year of growth depending on height/age of the tree. Timing for this application should be about two weeks prior to bud break. Also, foliar analysis this fall can help you gauge if your nitrogen program should be adjusted.

Table 1 shows the recommend rates for nitrogen applications.

Pale green to yellow foliage generally more on older foliage but trees will show a general overall color loss. Note: Off-color trees can also be an indicator of the pH being too high. Photo credit: J. Shelton, North Carolina State University.

Table 1. Annual application rates for nitrogen (amounts of actual nitrogen)

Planting year	No nitrogen recommended
Year 2	½ oz./tree	( 38 # per acre)*
Year 3	½ oz./tree	( 38 # per acre)*
Year 4	1 oz./tree	( 75 # per acre)*
Year 5 plus	1 oz+/tree	( 75 # + per acre)*
Year of harvest	1 to 5 oz./tree	(part in August for color depending on size of tree)

*Based on 1,200 trees per acre.

Pre-emergence herbicides for use in Christmas tree plantations
Mike Marshall
Department of Horticulture

Editor’s note: This article was first published in the April 13, 2007 Landscape Alert and has slight revisions by Jill O’Donnell to reflect this year’s activity.

Pre-emergence herbicides are useful in Christmas tree production to prevent competition from undesirable weeds. A couple of newer herbicides have recently been added to the list available for producers: Westar and SureGuard (flumioxazin). Westar (hexazinone plus sulfometuron) is a premixture of Velpar (hexazinone) and Oust (sulfometuron). Westar rates range from 6 to 12 oz/A. Use the lower rates on coarse textured soil and where conifer tolerance is a concern. SureGuard also provides good to excellent control of most weed species. Rates for SureGuard are from 8 to 12 oz/A. Add 1 pt/A to 1 qt/A of Roundup Original to the SureGuard tank as emerged weeds are present at spraying.

Previous research has shown both herbicides provide nearly season long control. Other products include Princep (simazine) at 2 qts/A plus Aatrex (atrazine) at 1 qt/A. Use only in fields where incidence of triazine resistance is not an issue. Kerb 50W (pronamide) at 3 to 4 lb/A plus Princep at 2 qts/A is also a good option.

Finally, Princep at 2 to 4 qts/A plus Surflan AS (oryzalin) at 3 to 4 qts/A or Pendulum EC (pendimethalin) at 2.4 to 4.8 qts/A or Pennant Magnum (s-metolachlor) at 1 1/3 qts/A or Barricade (prodiamine) at 2.3 lbs/A. The most important thing to remember is to apply these herbicides before budbreak. As with any herbicide product, please consult the label for specific rates and instructions regarding its use in your plantation.

Gypsy moth 2008 spray window dates and map
Mike Bryan, MDA

Each year Michigan Department of Agriculture and MSU Extension evaluate the progress of gypsy moth egg hatch in order to set the opening and closing dates for the gypsy moth spray window. This year we will continue to use the process started in 2007 where we will be using historical degree day accumulation data available online through MSU IPM Resources http://www.ipm.msu.edu/landscapeipm/gddlandchart.htm. The state has been divided into five gypsy moth spray window zones that roughly correspond to historical degree day trends. These zones are comprised of the counties shown below.

2008 gypsy moth spray window zones
Zone 1 - Berrien, Cass and Monroe counties.

Zone 2 - Allegan, Barry, Branch, Calhoun, Clinton, Eaton, Genesee, Gratiot, Hillsdale, Ingham, Jackson, Kalamazoo, Kent, Lapeer, Lenawee, Livingston, Macomb, Montcalm Oakland, Ottawa, Saginaw, Saint Clair, Saint Joseph, Sanilac Shiawassee, Tuscola, Van Buren, Washtenaw and Wayne counties.

Zone 3 - Antrim, Arenac, Bay, Benzie, Clare, Gladwin, Grand Traverse, Huron, Isabella, Lake, Leelanau, Manistee, Mason, Mecosta, Midland, Manistee, Muskegon, Newaygo, Oceana, Osceola and Wexford counties.

Zone 4 - Alcona, Alpena, Antrim, Baraga, Crawford, Delta, Dickinson, Gogebic, Houghton, Iron, Iosco, Marquette, Menominee, Missaukee, Montmorency, Ogemaw, Ontonagon, Oscoda, Otsego and Roscommon counties.

Zone 5 - Alger, Charlevoix, Cheboygan, Chippewa, Emmet, Keweenaw, Luce, Mackinac, Presque Isle and Schoolcraft counties.

Projected gypsy moth spray window dates
The accompanying chart shows projected open/close dates for application of the two groups of pesticides used for regulatory treatment of gypsy moth in nursery stock and Christmas trees. We are listing the projected dates as guidelines to help you plan your pest management program. Since gypsy moth development will vary by location, you will need to monitor development around your farm.

Click to see enlarged version.

Weather conditions will affect caterpillar development and may effect end date of the spray windows. Growers should watch the Landscape CAT Alerts for additional announcements.

As of April 18, degree-day accumulations were below normal for all of the state. Predicted degree-day accumulations shown on the MSU Enviro-weather web site indicate that the spray window open dates for Zones 1 and 2 for Dimilin will occur after April 26.

Zone	*Open – Dimilin (150 DD)**	Open – all other compounds (200 DD)	Close – Dimilin (700 DD)	Close – all other compounds (800 DD)
1	April 23 (projected) **	May 4 (projected)	June 9 (projected)	June 15 (projected)
2	April 28 (projected)	May 10(projected)	June 15 (projected)	June 20 (projected)
3	May 3 (projected)	May 15 (projected)	June 21 (projected)	June 27 (projected)
4	May 14 (projected)	May 21 (projected)	June 28 (projected)	July 4 (projected)
5	May 20 (projected)	May 27 (projected)	July 3 (projected)	July 11 (projected)

* DD = Degree Days at base 50 degrees F.
** Projections are based on 30-year historical degree day data.

Red squirrel injury to spruce
Howard Russell
MSU Diagnostic Services

Last week, we received two different samples comprised of only a half dozen or so cut off terminal ends of a blue spruce branch. Each 3 to 4-inch branch end had been neatly pruned from the tree. The tree owners had found piles of these cut-off ends on the ground around the base of their trees. They sent some to us hoping for some answers. A quick look at the buds revealed the centers had been eaten out. This was the work of our noisy little friends, the red squirrel.

Red squirrels, aka, pine squirrels and chickarees, are native rodents that can be easily identified from other North American tree squirrels by their smaller size, territorial behavior and reddish fur with a white under-belly. Red squirrels aggressively defend their territory from other squirrels. They get annoyed whenever large animals, particularly dogs and people, intrude onto their territory. Anyone who walks the woods recognizes the barks and chatter of an annoyed red squirrel.

Red squirrels have one the widest distributions of all North American squirrels. They occur in Alaska, across Canada to the northeast United States and south through the Appalachians. They also are found in the Rocky Mountains. The diet of these tree squirrels is specialized on the seeds of conifer cones and as such, they live throughout North America wherever conifers are common. There are 25 recognized

A nice photo of our noisy little friend, the red squirrel. Photo credit: M. Mengak, Univ. of Georgia, Courtesy of forestryimages.org

sub-species of red squirrels. They eat almost anything they can get their little hands on including spruce buds and needles, mushrooms, willow leaves, poplar buds and catkins, flowers and berries and animal material such as bird eggs and bark beetle larvae. In my woodlot, they seem to like walnuts.

Studies in Alaska where white spruce dominates suggest that white spruce seeds comprise over 80 percent of the caloric content of the red squirrels. White spruce cones are harvested by red squirrels and stored in a central cache called a midden. A midden provides the necessary food stores for surviving the winter and reproduction the following spring. Middens of red squirrels that live in predominately hardwood forests are probably comprised of nuts and other available foods. Red squirrel territories may contain only one or several middens. Juvenile red squirrels must acquire a territory and midden prior to their first winter. Juveniles without a midden do not survive their first winter and on average only 22 percent survive to one year of age. Red squirrels do not hibernate and remain active all winter long to defend their territory and middens (and consume vast quantities of bird seed from feeders where these are available.)

One of the more interesting things that have come out of these Alaskan studies is the ongoing struggle between the red squirrel and the white spruce. White spruce trees have developed a defensive strategy called a masting cycle to protect some of their cones from red squirrels. White spruce exhibits 2 to 6 year masting cycles, wherein most years they produce very few seed cones in an attempt to starve the juvenile squirrels, but once every six years or so they produce a superabundant number of cones which essentially overwhelms the red squirrel’s ability to harvest and store all of the cones like they do in years when few cones are produced. The result is that many more cones go uneaten during these mast years while at same time reducing the survivability of the juvenile red squirrels during the off years. Recent research suggests the red squirrels have adapted to this strategy by developing the ability to tell when a mast year is about to take place. In response, red squirrel females mate a second time and produce an additional batch of pups to take advantage of the large number of seed cones produced.

I don’t really know what to recommend to clients with red squirrel problems, though both Remington and Winchester manufacture products that provide effective red squirrel control and possibly a tasty meal. However, local ordinances regarding the discharge of firearms within city and other municipal boundaries, as well as the legal hunting season for red squirrel must be followed. If you have any other ideas, please contact me.

For more information on red squirrels see:
http://animaldiversity.ummz.umich.edu/site/accounts/pictures/Tamiasciurus_hudsonicus.html
http://www.redsquirrel.msu.edu/index.htm


The squirrels neatly prune the branch tips from the tree with a quick bite. Photo credit: H. Russell, MSU.	A close up of the spruce buds that were eaten by red squirrels. Photo credit: H. Russell, MSU.	Here are some the spruce branch tips that were sent in by clients last week. Photo credit: H. Russell, MSU.

Changes to Pesticide Regulation 637 are in effect immediately

The Michigan Department of Agriculture (MDA) has announced amendments to Regulation 637 - Pesticide Use - impacting the states licensed commercial pesticide applicator businesses and certified pesticide applicators. For the past year, a partnership consisting of state, industry and environmental leaders worked together to bring this regulation up-to-date, said Don Koivisto, MDA director. MDA will now begin notifying stakeholders of the revisions as well as ensuring all pesticide applicators are adhering to the changes.
Two key changes

Many of the amendments to the regulation simply clarify existing requirements; however, there are two significant amendments affecting turf and ornamental lawn markers and integrated pest management/parental notification requirements. The turf and ornamental lawn marker requirements are intended to return markers to their original symbolism and now restrict their use to pesticide applications only. While the regulation provides for immediate implementation, MDA is allowing applicators to use up remaining inventory of signs that comply with the previous requirements until June 30, 2008. On July 1, firms must begin using markers that comply with the revised rules. This will allow marker manufacturers time to produce a sufficient supply and move their product into the market.
In March 2005, requirements for schools and day care centers to implement integrated pest management (IPM) programs and notify parents prior to pesticide applications moved from the regulation into Public Act 451, Part 83. As such, many of these requirements have been removed from the revised rules.

MDA will offer compliance assistance meetings to help those affected understand how the revisions affect their business. Additionally, MDA mailed a notice of the revised rules to all 2008 licensed commercial pesticide applicator businesses and other impacted stakeholder groups.

For a copy of the revised regulation or information on a compliance meeting, visit the MDA web site at www.michigan.gov/mda.

Weather news
Jeff Andresen
Agricultural Meteorology
Geography

Changes in the upper air pattern across North America took place earlier this week. There has been a gradual westward shift of a troughing feature which has persisted across the central United States for much of the past few months. Accompanied by strong southerly winds, this shift has resulted in a noticeable increase in temperature. The morning of Friday, April 18, a stationary front was located across central sections of the Lower Peninsula. It is expected to remain stationary through the first part of the weekend, then slowly edge eastward as a cool front by Sunday. Look for a range of weather conditions across Michigan Saturday, with mostly sunny and abnormally warm weather over southern sections of the state and mostly cloudy and cool, and unsettled conditions north. Showers and a few thundershowers will be possible across northern sections of the state overnight Friday, with a chance statewide Saturday night into Sunday. Best chances for precipitation will be across central and eastern sections of the Upper Peninsula. Precipitation totals for Friday through Sunday should generally remain on the light side with most totals in the 0.10-0.50 inch range where rain occurs. Some areas may remain dry, especially south.

A second frontal system is forecast to approach the state by the middle of next week, with more rainfall possible Tuesday to Wednesday. Cooler and unsettled weather is a good bet across the state once again by the end of next week. Temperatures during the next few days will range from near normal levels across northern sections to above normal levels in the south, with highs ranging from the upper 40's or low 50's north to the mid-70's south Saturday. Highs will fall back a few degrees statewide Sunday to a range from near 50ºF far north to the mid- to upper 60's by Sunday continuing through Monday. Low temperatures should range from the upper 30's far north to the upper 40's south through Sunday. Normal temperatures for the third week in April range from highs near 50ºF north to 60ºF south, with lows falling to the mid- 30's north to the upper 30's south.

In the medium‑range, forecast guidance suggests a transitional pattern with the eventual return of upper air troughing and cooler weather by the end of April. Above normal precipitation totals are expected across Michigan and much of the Great Lakes region during both 6-10 day and 8-14 day time frames covering April 23-27 and 25-May 1. Temperatures during the 6-10 day period are forecast to range from near normal levels across the Lower Peninsula to below normal across Upper Michigan, cooling to below normal levels statewide during the 8-14 day period. Forecaster confidence in these outlooks is considered higher than normal due to good agreement amongst the individual forecast tools.

The MSU IPM Program maintains this site as an access point to pest management information at MSU. The IPM Program is administered within the Department of Entomology, fueled by research from the Michigan Agricultural Experiment Station, delivered to citizens through MSU Extension, and proud to be a part of Project GREEEN.
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Date: 04/18/08