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Chemical and Biological Control of Ailanthus altissima, the Last
of 3 Presentations
ABSTRACT: This is the third and final presentation on Ailanthus altissima (Tree-of-Heaven). It will show that Ailanthus altissima is easy to kill by chemical methods 24/7/365. At the same time, over several states and
years, a naturally occurring biocontrol system has been observed that is effectively killing Ailanthus altissima. This serves as a model for finding biocontrol systems
for other invasive non-native organisms and ending the scientifically unsound practice of introducing yet more
non-native organisms to control current and future problems.
Tree Physiology
Early in the life of Ailanthus the main root makes a right angle turn that is parallel with the ground as seen in this photo and the following.
Fluid flow is along a line @ 2” wide from the injection to the apical
meristems in the roots and branches.
This was found out by drilling a hole into the trunk and injecting 50.2% glyphosate then tracking
the death of the leaves and vascular cambium.
flu
i
d
f
l
o
w
Injection point
Injection point
The left fork of this trees was poisoned about 2 weeks before this photograph.
This and similar experiments were performed on several trees.
Male trees – notice the single clean peduncles
peduncle
peduncle
Female tree – notice the elaborate branching peduncles and seeds.
peduncles
peduncles with seeds
Biocontrol
Atteva aurea – the Ailanthus
web worm, super defoliator, taxi and disease vector.
A. aurea, November 19, 2012 on Solidago sp. along Blue Marsh, Berks County, PA.
egg
egg
larva
empty pupa shell
egg
larva
larva
larvae entering into pupa stage
pupae
This is a young tree full of communal A. aurea webs, a
common sight.
In this location 100% of the trees of all age groups had A.
aurea webs.
Communal webs
Another young tree with communal webs and disease
as shown by the dead branches and chlorosis.
chlorosis
Some A. aurea adults are apparently overwintering in central Pennsylvania as evidenced by the adults found feeding on Solidago species into late fall and the finding of larvae early after A. altissima goes
into leaf.
This could be caused by basic evolution as the A. aurea adapts to colder temperatures due to the availability of a new food source or due to global
warming.
It is most probably a combination of both.
The one question I have not been able to answer is the nectar source for A. aurea before
mid-summer.
I am assuming that the food source is a native Asteraceae as the later summer food sources I
have seen are Asteraceae family members.
Aculops ailanthii – killer of the young, bringer of disease and
death.
Diseased tree with Aculops ailanthii infestation.
Aculops ailanthii and chlorotic leaves on a mature tree.
A. aurea herbivory
A. Ailanthii mottling of leaves
A. aurea web
Fusarium and Verticillium –the third strike and death blow,disease strikes hard and fatally.
Fungi that infect A. altissima
Fusarium lateritium – lesionsFusarium oxysporum - wilt
Fusarium solani – lesions and wiltVerticillium albo-atrum - wilt
Verticillium dahliae - wilt
Fusarium lateritium macroconidia
Plate with Fusarium from diseased tree
Fusarium macroconidia from diseased tree.
Fusarium macroconidia from diseased tree.
Fusarium micro and macroconidia from diseased tree.
Fusarium micro and macroconidia from diseased tree.
With Atteva aurea, Aculops ailanthii and pathogens working
together death is certain.
Urbana, MD Community Park, September 2007.
The same stand in July 2011.
Pine Swamp Road, near Hawk Mountain, Fall 2011
Pine Swamp Road, near Hawk Mountain, August 2012.
Blue Marsh, August 2012
Blue Marsh, December 2012.
Compound leaf with A. aurea larvae and A. ailanthii.
This is the first biocontrol system I recognized, SGL 106 near Hawk Mountain, PA.
Birds – best for long distances
Moths – best for medium and short distances
Wind – best at short distances with high mite and tree densities
Transport of Aculops ailanthii across landscapes
Transport of Aculops ailanthii across landscapes
From recent walking it appears that there is a correlation between the density and nearness of the nectar sources adult Atteva aurea feed on
and the amount of disease in a stand of Ailanthus.
The key to finding a native biocontrol (system) for plant is to find an organism which is a generalist
herbivore for a family or genus and a specialist to that family or genus.
This means that the biocontrol has a the genetic ability to switch from one
plant to another and yet will not cause the extinction of coevolved food
sources.
A. aurea larvae eat other Simbouracae family members, but only eats
members of this family.
A. aurea larvae will preferentially eat a non-coevolved food source because it does not have the defenses to it that a
coevolved food source has.
Hence, an easy meal that is a higher quality food source (higher energy return for energy expended) than a
native coevolved one since it spends less energy dealing with chemical and
physical defenses.
At the same time it is embedded in a system of a mite (A. ailanthii) and
several diseases.
Which together interact to cause control of A. altissima.
Unique features of this system:1. A. altissima is the only food for A. aurea larvae in most of the A.
altissima range2. A. aurea adults are generalist nectar feeders
3. A. ailanthii is an apparent specialist to A. altissima4. A. aurea larvae have no other local food sources so the adults have spread themselves beyond their normal range by following
nectar sources and egg laying sites.5. A. aurea and A. ailanthii are the vectors for several A. altissima
diseases6. A. ailanthii apparently hitchhikes between A. altissima trees on
birds and A. aurea.7. A. aurea appears to evolving to colder temperatures as witnessed
by their presence feeding on goldenrod in central Pennsylvania in mid-November after frost and freeze.
How to develop an Ailanthusbiocontrol system:
1.) Do not apply pesticides to the surrounding area – herbicides,
insecticides, fungicides, … .
2. Plant a wide variety of native high nectar flowers nearby so there are
high quality food sources from mid-spring to first heavy freeze for the
adults to feed on.
So far I have found adult Atteva aurea on daisy-like flowers and at least 2
species of goldenrod from August to mid-November. I am still not sure
what they feed on from early spring when the Ailanthus leaves are just beginning to bloom to mid-August.
Chemical Control:Drill and Fill -
effective 24/7/365
This method was developed as a safe and efficient method for volunteers to
use in contained areas such as a township park.
Bartram Trail on May 31, 2012 of tree injected January 10, 2012.
Drill a 3/8” hole through the vascular cambium every 2” of girth at comfortable working height.
3/8” drill holes @ every 2” apart
Then spray 50.2% glyphosate (purple cap RoundUp®) into the
holes with a spray bottle.
If done in the summer, within a
week the leaves will begin
wilting and yellowing.
Within 2 weeks the leaves will
begin falling.
If the method is done in the winter, there may be a few vestigial leaves that try to form as it comes out of
dormancy.
However, the tree will still be dead by the end of the summer.
One day after injection in July 2011.
8 days after treatment in July 2011.
11 months after treatment, June 2012.
Day 0 at another location. I did this “as a volunteer” to test the robustness of the method.
Two weeks after injection.
End of summer at same site.
Day 0, five trunks with DBH from 8” to 44”.
17 days after injection.
Same stand in October, 4 months after injection.
Tree injected on January 10, 2012 then felled by Hurricane Sandy, October 29, 2012. Notice the burrows of ambrosia beetle Euwallacea
validus, (identified by Dr. Matthew T. Kasson) originating in the drill holes.
Small tree injected in June 20 then felled by Hurricane Sandy, October 29, 2012.
The three sure signs of tree death are:1.) no green layer under the bark
when scraped, 2.) white fungi growing around the
outside of the tree and 3.) loose/peeling bark.
It is essential that all dead trees around trails, roads and buildings be cut down within six months of dying.
Several trees poisoned in January and June 2012 fell in late October with
Hurricane Sandy.
Due to its exceptional growth rate Ailanthus does not develop the internal structures denser trees
develop which give them strength.
Once it dies, the tree falls and decomposes swiftly.
The reason this method works 24/7/365 is that glyphosate is
degraded primarily by microbes and not metabolized or detoxified by the
tree.
During tree dormancy the microbe population decreases substantially due
to severely slowed fluid flow within the tree and low environmental
temperatures.
As the tree moves out of dormancy and the sap begins to flow the
glyphosate poisons the tree most likely by killing the vascular cambium both ways along the vertical line between the injection site and the ends of the roots and stems while also poisoning the meristem tissue in the roots and
stems.
Method advantages:
1.) It does not use sharp blades. This reduces the potential for injury.
2.) All the materials can be found relatively inexpensively in most
hardware stores.
3.) Feedback is fast and can be watched as it develops. The results begin to show in less than one week with nearly complete defoliation of
trees in less than three weeks.
4.) This method can be done in the winter when the amount of brush is diminished and there are no biting
insects.
5.) Lastly, this method appears to be robust and may work on other plants such as Lonicera morrowii, Lonicera maackii, Broussonetia papyrifera,
Elaeagnus umbellate or other invasive woody plants.
In summary, this is an easy and safe volunteer friendly method which is
effective in eliminating Ailanthus altissima in discrete areas such as
parks. At the same time it is usable by professionals to cheaply remove
Ailanthus from small landscapes with a minimum of equipment and time.
Glyphosate environmental
non-target organism effects
Over 24 days there was an experiment to measure the affect of glyphosate in dropped leaves on plants, in this case a
lawn grass mixture.
Glyphosate in dropped leaves toxicity experiment on grass, day 0.
Glyphosate in dropped leaves toxicity experiment on grass, day 24.
• 16 trays were filled with potting soil and various grass seed mixtures over the summer. They were then placed under a row of mature Spruce trees.
• August 15, 2012 several branches were pruned from tree #2 before injection and the leaves frozen in 1 gallon Ziplock® bags.
• August 15, 2012 50.2% glyphosate was injected into 2 trees, #1 and #2 through 5/16” x 1-2” holes
• Leaves were collected after they fell, about 1 week later, and stored in a freezer.
• On August 31 the leaves were then spread across 16 trays of mixed lawn grass in potting soil as follows:o 2 trays left untouched, blank controlo 2 trays with water only, water controlo 6 trays with 100 grams leaves picked from trees before
injection with glyphosateo 6 trays with 100 grams glyphosate leaves
• On September 24, 2012 the experiment was concluded with no apparent differences between any of the trays.
Experiment Protocol
Other application:Paper mulberry,
Broussonetia papyrifera, killed by
Drill and Fill to demonstrate the
method robustness.
Future research1.) determining the food sources of
Atteva aurea in the late spring and the first half of summer.
2.) growing a biocontrol garden specific to Atteva aurea and Ailanthus
altissima control.3.) determining to the family the fungi that are infecting Ailanthus altissima
and their carriers.
The best way of destroying stands of Ailanthus altissima:
Plant native Asteraceae near the trees and leave alone.
The second best way to deal with Ailanthus altissima:
1.) Drill and Fill large trees.2.) Plant native Asteraceae nearby and
leave alone.
Ailanthus altissima biocontrol garden.
Ailanthus altissima biocontrol garden
2. Aster laevis 1. Asclepias tuberosa4. Erigeron speciosus 3. Aster novae-angliae6. Eupatorium perfoliatum 5. Eupatorium maculatum8. Monarda fistulosa 7. Heliopsis helianthoides10. Rudbeckia laciniata 9. Rudbeckia hirta12. Solidago canadensis 11. Rudbeckia triloba14. Solidago rigida 13. Solidago nemoralis16. Verbesina alternifolia 15. Solidago speciosa18. sunflowers 17. Asclepias syriaca19. Coreopsis 20. Shasta daisy21. sweet peppers 22. sweet peppers23. sweet peppers 24. Eu. mac./Cor.
trip./Ech. pur.
25. Collected plants
pasture uphill driveway
• originated in the neotropics and migrated north when a new food source was available – Ailanthus altissima.
• breed from early in the season until hard freeze – no diapause, this reinforces that they have not had enough time to change from a warm climate to a temperate species.
• females mate in the morning and then lay eggs in the evening.• webs are multigenerational with adult females laying eggs on the
webs made by other larvae.• from egg to adult is @ 21 days.• adults apparently overwinter at least as far north as central
Pennsylvania. • adults have at least a two color morphs, standard
orange/black/white and the same with a reddish cast.• adults are generalist nectar feeders at least in the Asteraceae
family.
Interesting facts about Atteva aurea
• larvae eat the young bark as well as leaves of Ailanthusaltissima, but no other plants.
• larvae have several color morphs from black to light brown and greenish.
• larvae form “tents” before they enter into the pupal stage by biting mostly through the rachis (mid-vein) of a compound leaf and letting it drop, then making a web around the resultant structure.
• aposematism is the primary defense in the same way as monarch butterflies – bright, colorful and easy to catch suggesting that there is no need for other defenses. Ailanthus altissima ingested as a larva probably make the larvae and adults unpalatable.
• easy to catch and easy to raise.
