Frank
1
Chris Frank
Peter Wilkin
Biology 205
30 October 2005
Emerald Ash Borer
Scientific Name: Agrilus planipennis or Agrilus marcopoli
Scientific Classification:
Kingdom: Animalia (taxonomic kingdom comprising all living or extinct animals)
Phylum or Division: Anthropodo (jointed-foot invertebrates: arachnids, crustaceans, insects,
millipedes, and centipedes)
Class: Uniramia (Insecta) (The uniramia is mainly abandoned taxon of arthropods, comprising
the Hexapoda – insects and allies and Myriapoda – centipedes, millipedes, and related forms.
The uniting feature was the nature of the appendages on the head and the walking legs. The
Crustacea were generally considered the closest relatives of the Uniramia). Insecta (class
Hexapoda – about five-sixths of all known animal species).
Order: Coleoptrea (beetles)
Family: Buprestidae (metallic wood-boring beetles, jewel beetles, and flatheaded borers.
Characterists include: first abdominal sternite entire, not divided by hind coxae, hard bodied,
clongate-slender to elongate-robust beetles, ranging from two to forty mm in length. Many
species metallic or bronzed in appearantce, especially on the ventral surface. Antennae usually
short and sawtoothed. Tarsi 5-5-5. Larvae have flat, broad thorax and live in bark, wood, roots,
and leaves of various plants. There are 700 species in North America, about 130 species in
Florida). http://eny3005.ifas.ufl.edu/lab1/coleoptera/Buprestid.htm
Subfamily: Agrilus (Curtis 1825)
The emerald ash borer is native to Eastern Asia. Its natural range is eastern Russia, northern
China, Japan, and Korea (Michigan.gov Home Website).
The emerald ash borer is an invasive species to Ontario, Canada and in the United States to
Ohio, Michigan, and in May, 2004 to Steuben County, Indiana. In the United States the emerald
ash borer was first discovered in Detroit, MI in July of 2002. It is believed to have been in that
area for about five years (Columbia University). It is further believed that the emerald ash borer
first came to the United States hidden in wooden packing material.
On their own, emerald ash borers move slowly through the landscape at a rate of about half a
mile per year. Humans are the major contributors to the spread of these insects by moving ash
wood, especially firewood into un-infested areas. It is believed that is how the emerald ash borer
arrived in Indiana (Purdue University). To view the parts of Indiana affected by the emerald ash
borer, http://www.ceris.purdue.edu/napis/pests/barkb/imap/eabin.html.
The ecological role of the emerald ash borer is the attack upon ash trees such as green
Fraxinus pennsylvanica, white F. Americana, and black F. nigra (Columbia University).
According to Cliff Sadof, a Purdue Cooperative Extension Service entomologist, the emerald ash
borer has killed 6 million ash trees in Detroit and poses a serious threat to the 147 million ash
trees in Indiana (Purdue News). The emerald ash borer has the potential to eliminate ash as a part
of North American forest which will have a tremendous affect on the ecosystem processes, as
well as plant and animal communities. Ash provides a habitat for wildlife and as it is destroyed
is creates unbalance of the wildlife dependent upon it. There will also be a great economic
Frank
2
impact. An Ohio Department of Natural Resources study estimated there to be more than 3.8
billion ash trees in Ohio. The timber value is more than $1 billion. Ash is also one of the most
important nursery and landscape species. “According to the USDA, wholesale value of ash sold
by Ohio nurseries exceeded $20 million in 1998, a market threatened by emerald ash borer”
(Buckeye Yard and Garden Line). It will cost approximately $300 million to try to control the
emerald ash borer in southeastern Michigan over the next 10-13 years.
The United States doesn’t have the predators, parasites and diseases which keep this insect
population low.
To view the emerald ash borer go to http://www.entm.purdue.edu/EAB/. The adult emerald
ash borer is metallic, golden or brassy green, with dark green wing covers called elytra. The tips
of the elytra are rounded, with small teeth along the edges. When the emerald color wings are
open, the metallic copper-red abdomen can be seen. The first pair of legs is attached to the
prothorax, which is slightly wider than the head and the same width as the base of the elytra.
The back edges of the prothorax covering are wavy, and the top of the prothorax has tiny,
transverse ridges. It has a boat shaped body that is somewhat flat. It is about a half inch in
length and 1/16th inch wide. The females are larger than the males. The emerald ash borer is
brighter and larger than any North American species of Agrilus (Columbia University).
The life cycle of the emerald ash borer can be seen in stages by going to the “Information
About Emerald Ash Borers” page of http://www.entm.purdue.edu/EAB/ . The adult females
mate in late May through mid-summer. The females lay eggs individually on bark surface or in
bark crevices on trunks or branches. The eggs are light yellow, oval shaped and about 4/100 of
an inch long. Each female lays about 75 eggs during her lifetime. The eggs hatch in seven to 10
days into wormlike larvae. The next stage of the life cycle includes three phases of larvae. After
hatching, the larvae bore through bark to feed on ash trees’ vascular tissue which transports
water and nutrients throughout the tree. As the larvae are growing they zigzag through the tree
tissue as they feed forming S-shaped tunnels. The tunnels are packed with excrement. Mature
larvae are about one inch long, creamy white, with a flat and broad-shaped body. The larvae live
under the bark in the winter. Next, is the pupae stage. The larvae begin this stage in April and
will turn into sexual mature adults. Larvae remain under the bark until they pupate. Adults
emerge from the tree as soon as they are fully developed. The adult emerald green ash borers
emerge from the tree through D-shaped exit holes beginning in April and continuing throughout
the summer. The adults live about twenty days.
They feed on ash leaves which don’t cause much damage (Purdue University). It’s the larvae
stage that does a great deal of harm to the tree. The larvae feed on Phloem and outer sapwood
just under the bark. The infestation progresses into the second year and the canopy will start to
thin and the branches will dieback. The decline accelerates rapidly, killing the tree within two to
four years of infestation.
So far there isn’t a particular method which proves to be successful in eliminating this
invasive species.
The following is an abstract proposing a plan of action to reduce the threat of invasive
species’ proposed in the BioScience research journal in 2005.
Frank
3
ABSTRACT
Invasive species pose a major, yet poorly addressed, threat to sustainable forestry. Here we set forth
an interdisciplinary science strategy of research, development, and applications to reduce this threat. To
spur action by public and private entities that too often are slow, reluctant, or unable to act, we
recommend (a) better integrating invasive species into sustainable forestry frameworks such as the
Montréal Process and forest certification programs; (b) developing improved cost estimates to inform
choices about international trade and pest suppression efforts; and (c) building distributed information
systems that deliver information on risks, identification, and response strategies. To enhance the success
of prevention and management actions, we recommend (a) advancing technologies for molecular
identification, expert systems, and remote sensing; (b) evolving approaches for ecosystem and landscape
management; and (c) better anticipating interactions between species invasions and other global change
processes.
There aren’t many natural enemies in the United States to combat and keep the Emerald Ash
Borer population density down. Woodpeckers are a good predator of the emerald ash borer
(Buckeye Yard and Garden Line).
Frank
4
According to an article in Agricultural Research Service by Luis Pons,
two species of wasps have been found which are natural enemies of the
Emerald Ash Borer. One is of the species Balcha, which like to snack on
the ash borer’s larvae. The other is of the genus Pediobius, which attack
its eggs. The specific wasp identities are unknown and finding the wasps’
precise identity will involve a great deal of research. The Pediobius
genus contains about 215 species alone with 32 of those in the United
States.
The Checkered Beetle is a native predator. In its larval state, it
feeds on clusters of EAB larvae. The adult Checkered Beetles also feed on adult Emerald Ash
Borers but it would take years before the Checkered Beetle to multiply to the point where it
would be able to keep population density down of the ash borers.
According to the USDA Forest Service in Lansing, Michigan, the most prevalent natural
enemies of the Emerald Ash Borer are five species of fungi. Fungal species include: Beauveria
bassiana, Pacilomyces farinosus, Paecilomyces fumosoroseus, Verticillium lecanni, and
Metarhizium anisopliae. Seven potential larval parasitoids include Heterospilus sp.
(Braconidae); Phasgonophora sulcata (Chalcidae); Balcha sp. and Eupelmus sp. (both
Braconidae). The most prevalent parasitoid was Balcha sp. Two other parasitoids include
Atanycolus and Spathius simillimus (both Braconidae). Colopteran predators include Enoclerus
sp. (Cleridae), Catogenus rufus (Passandridae), and Tenebroides sp. (Trogossitidae); these
beetles consume EAB during both larval and adult stages. Mortality rate of the EAB due to
parasitoids is low.
The natural enemies to the emerald ash borer prove to be of little help in keeping its
population down and because the ecological and economical results will be devastating research
continues and methods to minimize spreading are in place.
The USDA Forest Service is testing conventional insecticides in hopes of eradication of EAB
and to protect landscape ash trees. However, Michigan won’t allow the use of conventional
insecticides due to the vast area infected, legal issues and lack of public support. They are also
studying biopesticides formulated with isolates of Bacillus thuringiensis (Bt) and a product
formulated with Beauveria bassiana Var. GHA (Bb). The public is o.k. with the use of
biopesticides because of good safety records and compatibility with other management strategies
including biological control.
Finding a way to produce an ash tree that is resistant to the emerald ash borer may be
necessary in order to maintain ash trees in the United States. In Asia the emerald ash borer is
mainly a threat to already weak or diseased ash trees and hits hardest during times of drought.
Frank
5
The following is a hypothesis published in Secret Arboretum which is a news publication put out
by Ohio State University.
Our a priori hypothesis is that the Asian ash will prove to be most resistant
because of natural defenses resulting from coevolution with the insect. The
inclusion of the native-Asian hybrid may provide insight into patterns of
inheritance of resistance genes, and facilitate their identification.
Identification of resistant genotypes will be critical for reforestation, as
well as maintaining market demand for ash in the nursery industry.
Identification of resistance mechanisms and their relationship to whole tree
physiology will facilitate screening, selection, and/or breeding of resistant
trees, as well as cultural management of emerald ash borer in urban and
natural forests.
Another method to control the spread of infected trees is quarantine. This method has
been in place in infested sites in Michigan and Ohio (Buckeye Yard and Garden Line). The
quarantine prohibits the movement of ash trees, logs, branches, firewood, and untreated lumber.
Indiana also has a quarantine in two counties in Decatur. Firewood cannot be moved from
contaminated regions. (IndyStar.com). To view an alert notice,
http://www.entm.purdue.edu/EAB/eabPdf/firewood_alert.pdf.
Cutting down infected trees is another method of control. In LaGrange and Stueben counties,
110,000 ash trees have been taken down and more than six million ash trees have been removed
in Michigan (IndyStar.com).
Firebreaks have proven to be the best bet in stopping the spread of infested trees. “A
firebreak is a wide corridor next to an infested area where the invader is deprived of its food
source or suppressed with aggressive control measures, or both” (Main Control). When the
emerald ash borers are contained within the fire-break, they should die off because once the trees
are dead they will have no food source and will then die of starvation.
The emerald ash borer is a good example of the devastation can occur when an invasive
species is introduced into an ecosystem. Hopefully, with all of the researchers at work, there will
be a breakthrough in getting rid of these little pests and saving the ash trees.
Works Cited
Bennett, Pam, et al. Ohio State University Extension. Buckeye Yard and Garden Line. 2003.
“Special Ash Borer Issue.”
“Emerald Ash Borer Found Two Miles from Indiana Border.” Purdue News. 2005. 17 Sept.
2005. <http://news.uns.purdue.edu/UNS/html3month/030815.Sadof.emeraldash.html>.
“Emerald Ash Borer (Agrilus planipennis).” Columbia University. Invasion Biology Introduced
Species Summary Project. <http://www.columbia.edu/itc/cerc/danoft-burg/invasion_bio/
Inv_spp_summ/Agrius_plann…>.
“Emerald Ash Borer.” Wikipedia, the Free Encyclopedia. 29 Oct. 2005
<http://en.wikipedia.org/wiki/Agrilus_planipennis>.
Michigan.gov.Website. Department of Agriculture.
<http://www.michigan.gov/mda/0,1607,7-125-1568_2390_18298-44156--,00html>.
Miller, George, et al. Word Net-Princeton University Cognitive Science Laboratory.
20 Oct. 2005. <http://wordnet.princeton.edu/>.
“Working to I.D. Foes of Emerald Ash Borer.” Agricultural Research Service. 05 Nov. 2005.
<http://www.arg.usda.gov/is/AR/archive/feb05/borers0205htm?pf=1>.