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For Immediate Release: Wednesday, Sept. 12, 2018
New infestation of invasive pest discovered in Dike
DES MOINES – The
emerald ash borer (EAB), a destructive insect that attacks and kills ash trees,
has been detected for the first time in Grundy County. There are now 65
counties in Iowa with confirmed infestations.
Insect
samples were collected from a city-owned tree in Dike after an Iowa Department
of Agriculture & Land Stewardship (IDALS) worker noticed ash trees showing
the signs of a tree under attack. The collected samples were positively
identified as EAB by a federal identifier.
The
adult emerald ash borer is a metallic green insect measuring about one-half
inch long. The female beetles lay eggs on the bark of ash trees. Following egg hatch
the larvae bore into the bark to the fluid-conducting vessels underneath. The
larvae feed and develop, cutting the flow of nutrients and, eventually killing
the tree. EAB is native to Asia.
The
beetle can fly only short distances. There is also the ever-present risk of spreading
EAB and other tree-killing pests
through human transport of firewood. Use locally-sourced firewood when burning
it at home and when traveling, burn firewood where you buy it.
EAB-infested ash trees can include sparse foliage or
thinning of the canopy, excessive sprouting of epicormic shoots from the trunk
or main branches, increased woodpecker activity, serpentine (“S”-shaped) galleries under the bark, vertical bark
splitting, and 1/8 inch D-shaped emergence holes.
At
this calendar date, the window for all preventive treatments has closed. If a
landowner is interested in protecting a valuable and healthy ash tree within 15
miles of a known infestation, he or she should have landscape and tree service
companies bid on work, review the bids this winter, and treat beginning spring
2019 (early April to mid-May). More details pertaining to treatment are
available in Iowa State University Extension and Outreach publication PM2084: https://store.extension.iastate.edu/product/13114.To find a
certified applicator in your area, download PM3074 and follow the steps: https://store.extension.iastate.edu/product/Finding-a-Certified-Pesticide-Applicator-for-Emerald-Ash-Borer-Treatment.
The
State of Iowa continues to track the movement of EAB on a county-by-county
basis. To report a suspected infestation in a new location, contact one of the
following:
·
Iowa
Department of Agriculture & Land Stewardship, State Entomologist Office:
515-725-1470
·
Iowa
Department of Natural Resources: 515-725-8453
·
Iowa
State University Extension and Outreach, Entomology: 515-294-1101
To
learn more about EAB and to view known locations in Iowa, please visit http://www.iowatreepests.com.
For more information contact any of the
following members of the Iowa EAB Team:
·
Mike Kintner, IDALS EAB coordinator, 515-745-2877, Mike.Kintner@IowaAgriculture.gov
·
Robin Pruisner, IDALS state entomologist, 515-725-1470, Robin.Pruisner@IowaAgriculture.gov
·
Jeff Goerndt, DNR state forester, 515-725-8452, Jeff.Goerndt@dnr.iowa.gov
·
Mark Shour, ISU Extension and Outreach entomologist,
515-294-5963, mshour@iastate.edu
·
Tivon Feeley, DNR forest health program leader, 515-725-8453, Tivon.feeley@dnr.iowa.gov
·
Donald Lewis, ISU Extension and Outreach entomologist,
515-294-1101, drlewis@iastate.edu
·
Emma Hanigan, DNR urban forestry coordinator, 515-249-1732, Emma.Hanigan@dnr.iowa.gov
·
Laura Iles, ISU Extension and Outreach entomologist, ISU Plant
and Insect Diagnostic Clinic, 515-294-0581, ljesse@iastate.edu
·
Jeff Iles, ISU Extension and Outreach horticulturist, 515-294-3718,
iles@iastate.edu
Frequently Asked Questions and Answers on
Emerald Ash
Borer (EAB)
1.
What is the
emerald ash borer? It is a very small,
shiny green beetle (½ inch long x ⅛ inch
wide; about the
size of Mr. Lincoln’s image
on a penny).
2.
What does EAB eat? Hosts
are species (and cultivars) of ash in the
genus Fraxinus. Hosts include
green
ash (e.g., ‘Marshall Seedless’, ‘Patmore’,
and ‘Summit’), white ash (e.g., Autumn
Purple®) black ash, blue ash, and
pumpkin ash. Manchurian and Chinese
ash
trees are primary hosts
in
its homeland [Eurasia].
A new host record of
white fringetree (Chionanthus virginicus) was discovered
in Ohio; this is
not a common plant in
Iowa. Mountain ashes (Sorbus species) are NOT hosts.
3. Where is
EAB from? This beetle is native
to Asia and
is
found in China and Korea. It also
has
been reported in Japan, Mongolia, the Russian Far East, and Taiwan. EAB arrived in the United States sometime
before 2002 in wood packing materials. It has been
recorded feeding on F.
chinensis and F.
mandshurica as a native borer.
4.
How did it get to Iowa? Most EAB infestations in the United States have been started by people
unknowingly moving infested firewood, nursery plants, or sawmill logs. The adult beetle also can fly short distances (2 to 5 miles).
5.
Should I be
concerned about EAB? Yes.
It
kills ash trees, usually in 2-4 years. In the
Midwest,
millions of ash trees have been killed by EAB since
2002. There are
about 3.1 million
urban ash trees
and an estimated 52 million ash trees in
forests in the state
of
Iowa. Statewide, Iowa averages
16- 17% ash on city property,
though
the ash component in
tree inventories can reach 87%.
6.
How do I know if I
have an ash tree in my yard? Two sources to
check on tree identification are: https://store.extension.iastate.edu/ItemDetail.aspx?ProductID=1482 and
http://www.extension.iastate.edu/forestry/iowa_trees/tree_id.html
7.
How do I know if my ash tree is infested?
Look for the following symptoms: https://store.extension.iastate.edu/Product/EAB-or-Native-Borer
and https://store.extension.iastate.edu/Product/Common-Problems-of-Ash-Trees
a.
Canopy thinning or dying branches in
the
top
of
the tree
b.
Water sprouts (suckers) halfway up the trunk
c. Feeding notches on edge of leaflets
d.
Woodpecker feeding sites/many bark flakes on
lawn
e.
S-shaped feeding galleries under dead bark
f.
D-shaped exit holes
(1/8 inch diameter)
8.
For counties not yet known to be infested with EAB, who can
help me determine
if my tree is
infested? Contact one of the following if you
suspect EAB in
your tree:
a.
Iowa Dept. of Agriculture & Land Stewardship, State
Entomologist Office:
515-725-1470
b.
Iowa
Department of Natural Resources 515-725-8453
c. Iowa State
University Extension and Outreach, Entomology: 515-294-1101
9.
Who
should
be
thinking
about
treating ash trees? If you are
a homeowner within
15 miles of a known
infested area, you can consider treatment of a healthy ash tree during the
growing season (see #10 below). If you
are not in a known infested area, treatment may be premature.
10. Ash
Borer Management Options:
a. There
are two management publications available from Iowa State University Extension
1)
English: https://store.extension.iastate.edu/product/13114
2)
Spanish: https://store.extension.iastate.edu/product/14762
b. Ash trees can
be protected with insecticide applied by a
commercial pesticide
applicator or
the
homeowner. Trees must be healthy,
vigorously growing,
and valuable to your landscape.
c.
Most of the systemic
insecticide treatments (i.e., imidacloprid and dinotefuran) must be
done each year for the
life of the tree. Two active
ingredients will last for 2 years in a light EAB infestation:
emamectin benzoate and
azadirachtin. In
heavy
EAB infestations, only emamectin
benzoate is effective
for
2 years; azadirachtin must be injected
every year.
d. Keep
in mind that treatment may not
be effective for a given tree
due to past injuries,
age of the tree,
soil moisture,
soil compaction,
and other site
and environmental factors.
e. Preventive treatments are most effective. Infested trees
with less than
30%
dieback of the
crown might be saved for a few years,
but the tree’s crown will be
misshaped as a result of removing the dead
branches.
f. Ash trees within 15
miles of a confirmed
EAB
site are at risk of
EAB
attack. Preventive treatments are suggested within this risk zone,
but
may be premature outside this area.
Continued monitoring of
ash trees outside the risk zone for
EAB
symptoms is suggested.
g.
Systemic insecticides require time, good
soil
moisture, and active
tree
growth for distribution in
the ash tree. Most soil-applied products (soil
drench, granular, soil injection) must be applied in early spring (mid-April to mid-May) to
be effective. Basal trunk sprays [most effective for
trees <23”dbh] using dinotefuran can be applied from mid-May through
mid-June. Trunk injections can generally be made during full canopy (April
through August). Good soil moisture is critical for the effectiveness of any
preventive treatment.
h.
Soil drench
homeowner treatments
are effective for ash trees
up to 60 inches in circumference (20
inches diameter), while granular treatments are
recommended
for
trees up to 36
inches in circumference
(12 inches diameter). Homeowners
can make only one application per year. Trees
larger than 60 inches in
circumference (20 inch diameter)
will
need to be treated by a
certified commercial pesticide
applicator.
i.
There are several treatment options
available for ash trees when a commercial pesticide
applicator makes the application.
Always
use a certified
applicator with
experience in
treating trees. For
assistance in making a list of prospective certified applicators in your county/area, go
to: https://store.extension.iastate.edu/Product/Finding-a-Certified-Pesticide-Applicator-for-Emerald-Ash-Borer-Treatment
j.
There is a
per
acre use limitation for soil treatments and
basal bark treatments; consult the product label when planning applications. There is no per acre use limitation
for
trunk injections.
k. ISU Extension
and
Outreach does
NOT recommend canopy sprays
because of limited
effectiveness, the need
for
specialized equipment, spray drift, and
possible adverse
effects to
nontarget organisms.
11. If
I am contacted by
a pesticide
applicator to
treat ash trees for
EAB in the
fall or winter, what
course should I
take? The best time
for most preventive
applications for EAB is spring; some products
can
be used throughout the
summer and
early fall (before leaf color starts to change).
IF
you live within 15
miles
of
a confirmed EAB infested site, get an estimate for the treatment. It is
best to get at least one additional estimate before any work is
done. IF you live outside the risk zone, thank the
applicator for showing interest and
keep the company information on file.
12.
Where has EAB been found in
Iowa? EAB infestations have
been confirmed in sixty-five Iowa counties. Counties
considered infested:
1)
Adair – Bridgewater
(Mormon Trail Co. Park), Lake Orient Recreational Area (2016), Greenfield Lake
(2018)
2)
Adams – Rural
area north of Cromwell (2016)
3)
Allamakee –New Albin, Lansing, Black
Hawk Point, Plough Slough (2010)
4) Appanoose –
Moravia (2014)
5)
Benton – Belle Plaine (2017)
6)
Black Hawk–Waterloo (2014), Deerwood Park (2017)
7)
Boone – Boone (2014),
Ledges State Park (2017)
8)
Bremer–Waverly (2014)
9)
Buchanan – Winthrop (2018)
10) Buena
Vista – Alta (2017)
11) Butler
– Clarksville (2017)
12) Carroll
– Rural area west of Carroll (2018)
13) Cedar – Mechanicsville (2013)
14) Clarke
– Osceola (2016)
15) Clayton
– Marquette, Monona (2017)
16) Clinton
– Clinton
(2015)
17) Crawford
– Denison (2018)
18) Dallas – Waukee (2015)
19) Davis
– Rural area north of Bloomfield (2015)
20) Decatur
– Rural area north of Grand River (2017)
21) Delaware
– Edgewood (2018)
22) Des Moines – Burlington (2013)
23) Dubuque
– Dubuque (2015), Dyersville (2017)
24) Fayette
– Oelwein (2017)
25) Floyd
– Charles City (2017)
26) Greene
– east of Grand Junction (2017)
27) Grundy
– Dike (2018)
28) Hamilton
– Rural area near Randall (2018)
29) Hardin
– Eldora (2018)
30) Harrison
– Logan, Missouri Valley (2016)
31) Henry
– Mt. Pleasant (2014), Geode State Park (2017)
32) Howard
– Cresco (2017)
33) Iowa
– Lake Iowa Park (2016), north of Middle Amana (2017)
34) Jackson
– Bellevue (2017)
35) Jasper – Newton (2014), Rock Creek State Park (2017)
36) Jefferson – Fairfield (2013)
37) Johnson
– Coralville, Iowa City (2016), south of Oxford (2017)
38) Keokuk – Hedrick (2015)
39) Lee
– Fort Madison (2015)
40) Linn
– Cedar Rapids (2015), Toddville (2016), Lisbon (2017), Marion (2018)
41) Louisa
– Rural area in central part of county (2016)
42) Lucas –
Private woodlot (2014),
Chariton (2016)
43) Madison
– Rural site south of Winterset (2017), Winterset (2018)
44) Mahaska – Eddyville
(2014);
rural area NW of Oskaloosa (2015)
45) Marion
– Maryville (2014), Marion Co. Park (2017)
46) Marshall
– Rural area N of Le Grand (2018), Marshalltown (2018)
47) Monroe – Private property (2014),
Albia (2017)
48) Montgomery
– Rural area NW of Red Oak (2015); rural area north of Villisca (2016)
49) Muscatine – Muscatine (2014)
50) Page
– Clarinda (2018)
51) Polk
– Urbandale, West Des Moines (2015); Des Moines, Mitchellville, Windsor Heights
(2016), Johnston (2018)
52) Poweshiek
– Grinnell (2015), Montezuma (2017)
53) Ringgold
– west of Tingley (2017)
54) Scott
– Davenport (2015), Bettendorf (2016), Scott Co. Park (2017), West Lake Park
(2017)
55) Story – Story City
(2014), Ames (2018)
56) Tama
– Rural area N of Le Grand (2018)
57) Taylor
– Clearfield (2018)
58) Union – Creston (2013)
59) Van
Buren – Birmingham (2016)
60) Wapello – Eddyville (2014), Eldon (2017)
61) Warren
– Rural Milo (2017)
62) Washington
– Brighton (2016), Washington (2017)
63) Wayne
– north of Corydon (2017)
64) West
Pottawattamie – Council Bluffs (2018)
65) Winneshiek
– Decorah (2016)
13. Now that
EAB has come to Iowa, is there some plan to
manage/contain this
pest? A detailed plan has
been developed by Iowa’s
collaborative
agencies. The EAB Response
Plan
and other
current Iowa
information about EAB are given
at: http://www.extension.iastate.edu/psep/EmeraldAshBorer.html
14. What
does an EAB quarantine mean? A quarantine by state and U.S. agriculture
departments means that hardwood firewood,
ash logs, and wood chips cannot be
moved out
of the area without a
permit. Homeowners must not remove their ash tree
or firewood from their tree to an area
outside the quarantine. Tree removal companies must not haul logs
or firewood
outside the quarantine area
unless inspected and
treated as required by the
regulations.
15. How many counties in Iowa have been
quarantined? The entire state (99 counties) of Iowa has been quarantined for EAB.
16. What should a homeowner or tree care
company do with ash trees cut
down
in or near the infested area? We request that you dispose or use the wood
within your county.
17. Can I use the mulch produced by
chipping an EAB infested tree for landscaping? If the chip size is 1 inch x 1 inch or smaller (in
two dimensions), recent research has shown that EAB does not survive and the
chips can be used without concern. If the chip size is larger,
however, it is best to bury or burn these chips (according to local ordinance) as
soon as practical to prevent spreading EAB into new areas.
18. Can I use the wood from an EAB
infested ash as firewood? Yes, with
one qualification. Once the ash tree is cut into pieces, the pieces can be used
as firewood on your property. Please do not take infested firewood with you on
camping trips, tailgating, hunting, or other places because you will spread
EAB.
19. What can my ash tree be used for,
besides firewood? Depending on the straightness of
the trunk and main branches, ash killed by EAB can be processed for lumber or
can be debarked and used for outdoor furniture or landscaping. Pieces of scrap
wood with the bark still attached should be burned, buried, or chipped.
20. What
general recommendations
are
available to
communities? The
Iowa
Department of Natural Resources
has worked with several communities to
deal with
EAB infestations. Contact Tivon Feeley (515-725-8453) or
Emma Hanigan (515-249-1732) for more information.
21. Where can I find current information about
EAB on the Internet? Sites to gather current information about this exotic pest include:
a. National: www.emeraldashborer.info
b.
ISU Extension
& Outreach: http://www.extension.iastate.edu/psep/EmeraldAshBorer.html
c.
IDALS: www.IowaTreePests.com
d. IDNR:
www.iowadnr.gov/Environment/Forestry/ForestHealth/EmeraldAshBorer.aspx
22. Who
is a local contact? Call your county Iowa
State University Extension
& Outreach office for
more information:
·
Grundy
County 319-824-6979
If
you live in another Iowa county and would like to contact your Extension &
Outreach office, visit http://www.extension.iastate.edu/content/county-offices and click on your county; the
phone number is in the blue box in the upper right corner of a county’s web
page.
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For more information, contact Dustin Vande Hoef, (515) 281-3375 or (515) 326-1616 (cell) or Dustin.VandeHoef@IowaAgriculture.gov
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